The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: Science, bitch! on March 15, 2018, 08:20:45 PM
-
We can all agree, flat-earther and round-earther alike, that GPS, GLONASS, Galileo and similar systems work pretty well.
Supposedly those positioning systems rely on time signals from satellites orbiting earth, which in a flat earth model obviously wouldn't possible. I've read several times from flat-earthers that those systems have to somehow work differently, perhaps with ground-based beacons instead of satellites.
FES Consensus seems to be that NASA and other space agencies fake space travel out of greed, but aren't actually aware that the earth is flat.
However, to develop and operate GPS and similar systems, whether using satellites in space or radio beacons on earth, somebody obviously needs to be pretty aware of earth's actual shape.
GPS is operated by US Air Force. Does this mean the USAF knows earth is flat but didn't tell NASA?
GLONASS is operated by Roskosmos, Russia's space agency itself and Galileo is operated by ESA (European Space Agency). How is that possible without them knowing the earth is flat?
I'd like to know what your take is on that, flat-earthers.
This is a genuine question so junker, please refrain from moving it to CN.
-
We can all agree, flat-earther and round-earther alike, that GPS, GLONASS, Galileo and similar systems work pretty well.
I don't agree with that. There are numerous complaints online that GPS gives inaccurate distances. Look at this link: https://pmags.com/gps-mileage-discrepancies
Multiple examples are given, including the following quote:
And in the racing world, professionally surveyed half-marathon routes of 13.1 miles are called too short by people wearing GPS enabled devices. Some people less politely and less friendly, but still firmly, write the race directors and complain that the race course is 13.9 miles or even 14.2 miles. Some racers even are LESS polite. :O Why? Because their GPS enabled devices report higher mileage than what is on the race course.
USATF Certified tracks are measured with wheeled devices, and this distance differs when compared to GPS.
This author claims that GPS devices are inaccurate for finding distance, and that this inaccuracy grows with greater distance traveled (which is curious under the Round Earth model since GPS is just finding your coordinate and computing the distance to another coordinate).
Another quote from that link:
Your GPS-enabled watch, a GPS unit such as one bought at outdoor stores or an increasingly frequently used mobile devices are all Recreational Grade GPS units. They are good for knowing, more or less, where you are in a general location. You will not get pinpoint accuracy for location or distance. The effects of this inaccuracy is more noticeable the longer or more varied a jaunt.
See the bolded. If the Round Earth model is true, this is confusing, since GPS devices are just based on finding your coordinate and mapping how far away coordinate B should be. It should not matter how far away you map coordinate B. It should not increase in error the further away you map. The coordinates and the distance between them on a Round Earth should be known.
A comment at the bottom of that article showing that this is illogical:
It surprises me how much inaccuracy there seems to be. If my GPS knows my position within fifteen feet, there shouldn’t be a half mile discrepancy over fifteen miles.
The author of the article further asserts that "professional GPS equipment" is necessary, but does not suggest that he has ever used it, or show information that it is any more accurate for distances. Such equipment may be more accurate for showing current coordinate with higher resolution, beyond the accuracy of consumer GPS (which measures in 3 to 7 meters, not on the range of miles), but it does not follow that such professional devices are more accurate for "measuring distances". The distance between coordinate points on a Round Earth should be known in all systems.
-
We can all agree, flat-earther and round-earther alike, that GPS, GLONASS, Galileo and similar systems work pretty well.
I don't agree with that. There are numerous complaints online that GPS gives inaccurate distances. Look at this link: https://pmags.com/gps-mileage-discrepancies
Multiple examples are given, including the following quote:
And in the racing world, professionally surveyed half-marathon routes of 13.1 miles are called too short by people wearing GPS enabled devices. Some people less politely and less friendly, but still firmly, write the race directors and complain that the race course is 13.9 miles or even 14.2 miles. Some racers even are LESS polite. :O Why? Because their GPS enabled devices report higher mileage than what is on the race course.
USATF Certified tracks are measured with wheeled devices, and this distance differs when compared to GPS.
This author claims that GPS devices are inaccurate for finding distance, and that this inaccuracy grows with greater distance traveled (which is curious under the Round Earth model since GPS is just finding your coordinate and computing the distance to another coordinate).
Another quote from that link:
Your GPS-enabled watch, a GPS unit such as one bought at outdoor stores or an increasingly frequently used mobile devices are all Recreational Grade GPS units. They are good for knowing, more or less, where you are in a general location. You will not get pinpoint accuracy for location or distance. The effects of this inaccuracy is more noticeable the longer or more varied a jaunt.
See the bolded. If the Round Earth model is true, this is confusing, since GPS devices are just based on finding your coordinate and mapping how far away coordinate B should be. It should not matter how far away you map coordinate B. It should not increase in error the further away you map. The coordinates and the distance between them on a Round Earth should be known.
A comment at the bottom of that article showing that this is illogical:
It surprises me how much inaccuracy there seems to be. If my GPS knows my position within fifteen feet, there shouldn’t be a half mile discrepancy over fifteen miles.
The author of the article further asserts that "professional GPS equipment" is necessary, but does not suggest that he has ever used it, or show information that it is any more accurate for distances. Such equipment may be more accurate for showing current coordinate with higher resolution, beyond the accuracy of consumer GPS (which measures in 3 to 7 meters, not on the range of miles), but it does not follow that such professional devices are more accurate for "measuring distances". The distance between coordinate points on a Round Earth should be known in all systems.
You need to understand that GPS provides a position with a known accuracy and repeatability. It is the application that uses that data and may be inaccurate.
Please look at professional equipment and its use.
The USA uses GPS with Cruise missiles, how accurate is their use?
What is your view of the WGS-84 model, are you happy with its accuracy?
-
Also, anyone can read the rest of the page Tom linked, and the more in-depth pages linked from there, that explain how the technology works and how the errors appear. It is not because the Earth is flat.
also remember that the satellites used in GPS aren't supposed to exist in flat Earth belief, so acknowledging their existence in an attempt to prove the Earth is flat is a contradiction in terms
-
Tom, you need to stop attacking this strawman. You're comparing apples and oranges in what is being discussed. You keep talking about it computing the distance from you to point B, and then how it's inaccurate when walking those distances. Well, when you walk those distances it's no longer simply a discussion of calculating the distance from point A to point B. It's calculating the distance from point A, to point ZZ, using points A, B, C, D, E....WW, XX, YY, ZZ. Each of those points taken based upon a location at a particular point in time with a percentage error, based on the device used, for each point. What you *should* be comparing, is the distance a GPS system gives between point A and point B, and then comparing that to the distance said wheeled device gets. That would be an accurate comparison between the two. Or better yet, plot a route using your GPS, see how long it says it is for distance. Then drive it and compare both odometer, and GPS final distance given. This will show you any error in the calculated distance, as well as the known error in the tracking distance. This also answers why professional grade equipment will have a more accurate distance measurement, because the error in location is lower, and thus there is less error between each point from A to ZZ. The software used will also have an impact on this, with your phone GPS using understandably less expensive (and thus less precise) software.
It's absolutely fascinating that you can keep referencing and sourcing that article, but disregard every bit of information it provides about higher accuracy mapping it provides for some reason.
-
We can all agree, flat-earther and round-earther alike, that GPS, GLONASS, Galileo and similar systems work pretty well.
I don't agree with that. There are numerous complaints online that GPS gives inaccurate distances. Look at this link: https://pmags.com/gps-mileage-discrepancies
Multiple examples are given, including the following quote:
And in the racing world, professionally surveyed half-marathon routes of 13.1 miles are called too short by people wearing GPS enabled devices. Some people less politely and less friendly, but still firmly, write the race directors and complain that the race course is 13.9 miles or even 14.2 miles. Some racers even are LESS polite. :O Why? Because their GPS enabled devices report higher mileage than what is on the race course.
USATF Certified tracks are measured with wheeled devices, and this distance differs when compared to GPS.
This author claims that GPS devices are inaccurate for finding distance, and that this inaccuracy grows with greater distance traveled (which is curious under the Round Earth model since GPS is just finding your coordinate and computing the distance to another coordinate).
Another quote from that link:
Your GPS-enabled watch, a GPS unit such as one bought at outdoor stores or an increasingly frequently used mobile devices are all Recreational Grade GPS units. They are good for knowing, more or less, where you are in a general location. You will not get pinpoint accuracy for location or distance. The effects of this inaccuracy is more noticeable the longer or more varied a jaunt.
See the bolded. If the Round Earth model is true, this is confusing, since GPS devices are just based on finding your coordinate and mapping how far away coordinate B should be. It should not matter how far away you map coordinate B. It should not increase in error the further away you map. The coordinates and the distance between them on a Round Earth should be known.
A comment at the bottom of that article showing that this is illogical:
It surprises me how much inaccuracy there seems to be. If my GPS knows my position within fifteen feet, there shouldn’t be a half mile discrepancy over fifteen miles.
The author of the article further asserts that "professional GPS equipment" is necessary, but does not suggest that he has ever used it, or show information that it is any more accurate for distances. Such equipment may be more accurate for showing current coordinate with higher resolution, beyond the accuracy of consumer GPS (which measures in 3 to 7 meters, not on the range of miles), but it does not follow that such professional devices are more accurate for "measuring distances". The distance between coordinate points on a Round Earth should be known in all systems.
That article you linked doesn't really fit the topic. It discusses shortcomings of recreational GPS devices in accuracy of the distance travelled.
It's not about discrepancies in absolute A to B distances. Those obviously don't increase with distance.
What the article deals with is discrepancies in the distance covered on hiking trips or similar, and those trackers obviously don't measure the absolute distance between starting and ending position, but rather record the route and calculate it's length. Thus, obviously discrepancies add up with the length of the route. Main issue here is the refresh interval, I've added a graphic to illustrate that, the green line from A to B being the actual route, the red dots being the positions measured by the GPS device and the red line being the route tracked by the device. In most cases, the GPS-tracked route will be significantly shorter than the actual route, this getting worse with larger refresh intervals.
Anyway, we're splitting hairs here, I said GPS "works pretty well" not it "works perfectly".
Back to the other 6 paragraphs of my OP that you didn't address.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
-
yo that's like reading the top half of a speed limit sign (https://en.wikipedia.org/wiki/Speed_limit#/media/File:MUTCD_R2-1.svg) and saying, all we know is there IS a speed limit, but we don't know what it is
just your basic cherry picking, I guess. it seems beneath you. hopefully everyone reading this sees through you
-
(which is curious under the Round Earth model since GPS is just finding your coordinate and computing the distance to another coordinate).
...
If the Round Earth model is true, this is confusing, since GPS devices are just based on finding your coordinate and mapping how far away coordinate B should be. It should not matter how far away you map coordinate B. It should not increase in error the further away you map. The coordinates and the distance between them on a Round Earth should be known.
that's not at all how gps works. knowing the distance between two arbitrary points on the surface of a sphere doesn't tell you anything about real path lengths. how could it? that doesn't make any sense.
knowing that the distance from my home to the grocer is 5 miles tells me nothing about the length of the path i travel to get there.
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
you saw a black swan did a google image search for black swans and found one, so all you know is that all swans are black. okay.
-
I didn't point you to a single instance where GPS was inaccurate. I pointed you to multiple instances.
Whether you want to argue that GPS is inaccurate because of bad technology, that is fine. GPS is still inaccurate in determining distances.
-
I didn't point you to a single instance where GPS was inaccurate. I pointed you to multiple instances.
Whether you want to argue that GPS is inaccurate because of bad technology, that is fine. GPS is still inaccurate in determining distances.
you only pointed to instances in which (some) gps units were inaccurate in determining path lengths.
and why wouldn't it be? gps isn't a thing that tells you distances or path lengths. it's a thing that tells you where you are. working out the distance between two points is trivial, but that doesn't tell you anything about how long was the path i took to get from point A to point B.
-
plus, like, if you have 10000 swans, and three of them are black swans, you can point out multiple black swans. it's still cherry picking
-
I didn't point you to a single instance where GPS was inaccurate. I pointed you to multiple instances.
Whether you want to argue that GPS is inaccurate because of bad technology, that is fine. GPS is still inaccurate in determining distances.
Shall we point you to the millions of times it is accurate daily? Saying GPS doesn't work because it is occasionally wrong is beyond absurd. I use it daily, it is highly accurate. You're just killing any credibility you had with these ridiculous assertions that are not borne out by fact.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Do you really not undefstand how GPS is used? Low cost satnavs are used by millions to calculate routes and arrival times and work well. They are accurate and reliable.
The maps in a satnav calculate the distance to a destination. GPS simply provides accurate locations for the software to use.
You are concerned about measured distances of a track and it is explained to you how that works, it is not an issue.
-
There are numerous complaints online that GPS gives inaccurate distances. Look at this link: https://pmags.com/gps-mileage-discrepancies
Multiple examples are given ...
... but they're merely multiple examples of the same thing. A GPS-based calculation on a consumer-grade device of an "as the crow flies" distance between two points differs from that recorded by someone taking a path, on foot, between them. Big whoop.
Or that these consumer-grade devices, showing latitude and longitude to one or two decimal places don't show the user's exact position. Again, big whoop. You need more decimals to do that.
USATF Certified tracks are measured with wheeled devices, and this distance differs when compared to GPS.
.... but doesn't the GPS system merely indicate one position, at one time? If you want to take two positions, and calculate distance between them, that is done by some software on the device in use?
For further reading;
https://geodesy.noaa.gov/CORS/Articles/Accuracy.pdf
https://www.gps.gov/systems/gps/performance/accuracy/#speed
-
I didn't point you to a single instance where GPS was inaccurate. I pointed you to multiple instances.
Whether you want to argue that GPS is inaccurate because of bad technology, that is fine. GPS is still inaccurate in determining distances.
OK. It has been explained to you what your confusion here is, so I won't repeat it.
I've just checked my phone, I am where it says I am. Maybe not to the centimetre - which is the cause of the errors you are citing, small errors add up over a journey (he says, explaining what has already been explained to you, having said he wouldn't) - but basically, I'm where it says I am. I tried it at home the other day, it was right then too.
So, in brief: GPS works.
And it works because of satellites orbiting the globe - fun fact, that's what the G in GPS is for.
So even if there are some glitches and inaccuracies, I don't see how this adds any weight to the flat earth argument. To do that you'd have to show that GPS works in some other way than by using orbiting satellites. To save us both some time, I've see you muttering about eLORAN before and I've seen other people explain how that doesn't even work the same way and there's no way a GPS receiver could work using eLORAN.
So either:
There's another global conspiracy by people who pretended they launched GPS satellites and other people pretending that GPS works by satellites, all to keep this very important secret that the earth is actually flat safe, because obviously it's very important that this truth is kept from the general public.
Or...GPS works exactly how it's stated it works, because we live on a globe.
-
I've just checked my phone, I am where it says I am.
That would not be thanks to GPS, not unless you're in the middle of the Australian outback or the Sahara desert. Both big players on the mobile phone OS market rely on non-GPS data to get your location. Wi-Fi access points are currently the most useful data points for urban areas, and mobile phone networks are a common source for less densely populated zones (possibly because Wi-Fi access points and mobile phone towers are not allegedly zooming through space).
https://en.wikipedia.org/wiki/Wi-Fi_positioning_system
https://en.wikipedia.org/wiki/Hybrid_positioning_system
And, shockingly enough, if you check your phone somewhere that doesn't rely on WPS or mobile network towers, your location data becomes quite inaccurate.
So either:
There's another global conspiracy by people who pretended they launched GPS satellites and other people pretending that GPS works by satellites, all to keep this very important secret that the earth is actually flat safe, because obviously it's very important that this truth is kept from the general public.
Or...GPS works exactly how it's stated it works, because we live on a globe.
Third option: You're not as tech-literate as you think you are and you fallaciously assume that GPS data is the only dataset used in mobile phone location tracking. You're attributing the efficacy of big data and very recent developments in fingerprinting to a rather simple system that's been conceived of 40 years ago. Round or flat, that ain't how it works.
-
Having done a bit of Googling it does seem that a mix of GPS and non-GPS data is used for iPhone location.
BUT, that doesn't refute the general point that GPS works and is used by many industries.
-
Having done a bit of Googling it does seem that a mix of GPS and non-GPS data is used for iPhone location.
"A mix of multiple non-GPS data sources with an occasional and reluctant sprinkle of GPS" would be a much more accurate phrasing, given the subject matter.
BUT, that doesn't refute the general point that GPS works and is used by many industries.
It kinda-sorta-maybe works, except when it doesn't. That is the central point, which you are now attempting to ignore. You attempted to divert this discussion onto the path of "all you need to do is grab your phone and boom, GPS proven," when it is nowhere near this simple.
As someone who's been using actual GPS for geotagging my photographs, I have developed an intuition of just how much one can expect from it. I'd encourage you to do the same.
-
As someone who's been using actual GPS for geotagging my photographs ....
With which device(s) ... ?
-
Third option: You're not as tech-literate as you think you are and you fallaciously assume that GPS data is the only dataset used in mobile phone location tracking. You're attributing the efficacy of big data and very recent developments in fingerprinting to a rather simple system that's been conceived of 40 years ago. Round or flat, that ain't how it works.
None of that is relevant. There are handheld GPS devices that work far out of the reach of cell phones. I've used them when hiking in remote areas. Very accurate.
Enjoy this website that tracks shipping traffic via satellite. Not GPS, but still relevant as it is a global positioning system provided via satellite.
https://www.marinetraffic.com/en/ais/home/centerx:-12.0/centery:25.0/zoom:4 (https://www.marinetraffic.com/en/ais/home/centerx:-12.0/centery:25.0/zoom:4)
-
It kinda-sorta-maybe works, except when it doesn't. That is the central point....
What about my Garmin GPS watch? I can see it is incredibly accurate because the route it shows me on the map is exactly where I know I've been. Doesn't connect to Wifi, no phone signal, doesn't even have Bluetooth activated. Is it just luck?
-
As someone who's been using actual GPS for geotagging my photographs, I have developed an intuition of just how much one can expect from it. I'd encourage you to do the same.
OK. So, basically, you don't think GPS is that accurate. Other people are saying it is.
Whatevz. Honestly, I don't care. The fact is GPS is a thing and it works. You say yourself you use it.
The central point is not how accurate it is or whether iPhones use GPS data alone.
The central point in the context of FE vs RE is that GPS works using a series of satellites which orbit the globe. Ergo, we live on a globe.
If you have any evidence to the contrary then I'd be interested to hear it.
-
What about my Garmin GPS watch? I can see it is incredibly accurate because the route it shows me on the map is exactly where I know I've been. Doesn't connect to Wifi, no phone signal, doesn't even have Bluetooth activated. Is it just luck?
Presumably. Your experience contradicts that of my own and virtually everyone I've spoken to about the subject. It also contradicts the technical specification of GPS.
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS - most of the tracking data unsurprisingly seems to come from 9-dof accelerometer/magnetometer units. This, of course, resolves the contradictions you've just raised.
-
Could we now please proceed to the essential part of my question?
My intention was not to spark a debate about the accuracy of GPS, and I deliberately left open whether those systems rely on satellites (which obviously I and most fellow round-earthers have no reason to doubt) or something else like ground-based radio beacons like some flat-earthers claim.
What I was getting at was why flat-earthers think it reasonable to claim that NASA and other space agencies are not aware of the shape of earth.
FES Consensus seems to be that NASA and other space agencies fake space travel out of greed, but aren't actually aware that the earth is flat.
However, to develop and operate GPS and similar systems, whether using satellites in space or radio beacons on earth, somebody obviously needs to be pretty aware of earth's actual shape.
GPS is operated by US Air Force. Does this mean the USAF knows earth is flat but didn't tell NASA?
GLONASS is operated by Roskosmos, Russia's space agency itself and Galileo is operated by ESA (European Space Agency). How is that possible without them knowing the earth is flat?
-
What about my Garmin GPS watch? I can see it is incredibly accurate because the route it shows me on the map is exactly where I know I've been. Doesn't connect to Wifi, no phone signal, doesn't even have Bluetooth activated. Is it just luck?
Presumably. Your experience contradicts that of my own and virtually everyone I've spoken to about the subject. It also contradicts the technical specification of GPS.
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS - most of the tracking data unsurprisingly seems to come from 9-dof accelerometer/magnetometer units. This, of course, resolves the contradictions you've just raised.
GPS receivers do exactly what they say, they provide an accurate location from orbiting satellites.
Please explain the contradiction.
-
Here is another, way better source: http://fellrnr.com/wiki/GPS_Accuracy (http://fellrnr.com/wiki/GPS_Accuracy). The author overlays GPS route plots onto maps, compares a bunch of different devices, and goes into some detail about how the technology works.
point is, it does
-
Presumably. Your experience contradicts that of my own and virtually everyone I've spoken to about the subject. It also contradicts the technical specification of GPS.
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS - most of the tracking data unsurprisingly seems to come from 9-dof accelerometer/magnetometer units. This, of course, resolves the contradictions you've just raised.
So if it doesn't need GPS, why does Garmin bother saying it does? And if it demonstrably does (but not just) use GPS, are you conceding that GPS works? What's the point of GPS that doesn't work? Why would that even exist? To whose material benefit? It can't be for profit as any competitor could come along with their product and say "Look! Our product is just as accurate as Garmin's, is cheaper and doesn't rely on GPS!" and they'd clean up.
Accelerometer and magnetometer combined cannot deliver the accuracy. This is nonsense.
Anyway, back to the OP - good luck with getting a straight answer.
-
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS - most of the tracking data unsurprisingly seems to come from 9-dof accelerometer/magnetometer units. This, of course, resolves the contradictions you've just raised.
One glaring issue - I can remove the battery pack, go somewhere, replace the pack, power up and wait for the unit to receive location data. It shows me almost exactly where I am. Accelerometers can only detect inertial changes. They can only track changes in motion, not tell you where you are. You can keep trying to obfuscate, but you have no factual leg to stand on.
-
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS - most of the tracking data unsurprisingly seems to come from 9-dof accelerometer/magnetometer units. This, of course, resolves the contradictions you've just raised.
One glaring issue - I can remove the battery pack, go somewhere, replace the pack, power up and wait for the unit to receive location data. It shows me almost exactly where I am. Accelerometers can only detect inertial changes. They can only track changes in motion, not tell you where you are. You can keep trying to obfuscate, but you have no factual leg to stand on.
and tracking data in terms of location and track will use GPS, your movement will use the accelerometer/magnetometer.
-
What about my Garmin GPS watch? I can see ....
Presumably. Your experience contradicts that of my own and virtually everyone I've spoken to about the subject. It also contradicts the technical specification of GPS.
Which aspect of the Garmin's operation contradicts which part of the 'technical specification' of GPS, in your mind?
That said, even a quick Google search reveals that your Garmin watch almost certainly does not just use GPS ...
What would it take to make you absolutely certain, not just 'almost' ... ?
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Your proof of that statement is - Where?
Instead of spending your time trolling the net for cherry picked instances which seem to fit your viewpoint, if you wish to make an attempt at discrediting GPS, why not put your esteemed "Zetetic Principle" to good use and do a little first hand observation? Grab your GPS (not a phone, but a REAL GPS receiver), hit the road and test its accuracy against known positions and known distances while out for a Sunday drive to a favourite picnic spot? Then come back here and report its serious inaccuracy for all of us to witness.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Your proof of that statement is - Where?
See the link I provided. People attempted to determine their distance and they could not.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Your proof of that statement is - Where?
See the link I provided. People attempted to determine their distance and they could not.
In the link you provided, the first paragraph is:
Recreational GPS units are useful for giving reasonable accuracy in location, giving elevation and tracking overall pace. Recreational GPS units are not suitable for providing accurate total distance covered. The mileage on the odometer, if you will, is often on the higher side. As much as 10% in some cases.
So you admit that RECREATIONAL GPS devices are reasonably accurate at giving location, elevation and speed readings, but tend to over report distance traveled? So what you're saying is that GPS works and even cheapo models do an alright job of giving location? Cool, welcome to the round Earth.
It is important to note the recreational part of the story. The GPS signal doesn't 'tell' you where you are. The device has to calculate it. Cheaper devices aren't going to be as accurate.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Your proof of that statement is - Where?
See the link I provided. People attempted to determine their distance and they could not.
Several people including myself have conclusively explained to you why the phenomena described in that article you linked are irrelevant to this topic.
What I conclude from your refusal to accept that is, you're just messing with us and don't actually believe what you say.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
The word wrong is an absolute. If my GPS determined the distance from my house to the grocery store to be 6.002356 miles and I were somehow able to determine that the actual distance was 6.002355 miles, then I could say that my GPS was wrong. It was pretty damned accurate, but wrong nonetheless. This tends to make yours a null statement, in that it provides no real information regarding GPS accuracy.
I will certainly agree that my GPSs are never spot on, but, given that they are all consumer level devices, I am almost always impressed with their level of accuracy, normally well within 5 meters and very often within 2 or 3 meters.
-
As someone who's been using actual GPS for geotagging my photographs, I have developed an intuition of just how much one can expect from it. I'd encourage you to do the same.
I have used an actual GPS in my aircraft for descending to earth, at night and in cloud, with mountains around me. This is scary, but used by many privately owned aircraft every day, as well as the 'big' airlines.
The use of GPS, without any secondary source of navigation, is allowed by the national aviation authority and their reasoning for it is that:
GPS derived position accuracy is currently stated to be 100m or less, 95% of the time, and 300m or less, 99.9% of the time.
So they have designed their routes and approaches to airports, descending through mountains, based on this criteria, with an additional margin obviously for instrumentation errors, piloting errors etc.
Their main interest is the safety of the general public, which we are all grateful for.
People attempted to determine their distance and they could not.
FWIW this makes your point arguing at the margins, as people (in planes) determine their distance from mountains every day by use of GPS and they all survive to do it again ... the next day.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
Your proof of that statement is - Where?
See the link I provided. People attempted to determine their distance and they could not.
You need to understand that GPS gives an accurate position and distance is determined by software which uses the position data.
-
See the link I provided. People attempted to determine their distance and they could not.
One more time;
"A GPS-based calculation on a consumer-grade device of an "as the crow flies" distance between two points differs from that recorded by someone taking a path, on foot, between them (not necessarily keeping to a straight line). Big whoop."
As the poster says above, the calculation of the distance between points is not a function of the GPS system, it's done by software using that data. Claiming the software's result is 'wrong' does not equate to GPS itself being 'wrong'.
-
Which aspect of the Garmin's operation contradicts which part of the 'technical specification' of GPS, in your mind?
Not the operation itself. I'm willing to assume that the watch operates correctly. It's the accuracy of the statement that I severely doubt, for reasons explained immediately prior and afterwards.
What would it take to make you absolutely certain, not just 'almost' ... ?
Nothing - unlike RE'ers, I always accept the possibility that I might be mistaken. But to increase my confidence: the model of the watch would be a good start. Their documentation seems reasonably available, so that should easily let us confirm my suggestion. That said, I haven't found any Garmin watches which rely solely on GPS.
are you conceding that GPS works?
I thought I made myself perfectly clear. For a particularly low standard of accuracy, GPS works. That's why it's usually used as supplementary data in positioning systems.
Allow me to remind everyone that the key contention here is whether GPS works well or not. Not whether or not it exists. Accounts along the lines of Stinky's "I used it and it almost told me where I was!" are unlikely to swing it in either direction.
-
That's why [GPS] is usually used as supplementary data in positioning systems.
In aviation GPS is approved as primary means of navigation for descending in between mountains in cloud, at night.
Allow me to remind everyone that the key contention here is whether GPS works well or not. Accounts along the lines of Stinky's "I used it and it almost told me where I was!" are unlikely to swing it in either direction.
When you are in an aircraft descending as I described above, having a navigation system that "almost tells you where you are" is obviously useless to a pilot. Fortunately GPS is a lot more accurate than some more traditional means of radio navigation.
I'll repeat: GPS derived position accuracy is currently stated to be 100m or less, 95% of the time, and 300m or less, 99.9% of the time. It is also said that apparently the US DoD has guaranteed a maximum error of 500m.
The Aviation GPS receivers have a built in integrity monitoring of the position accuracy. When it receives GPS signal from 5 sources, it is able to do fault detection (it knows when the position is not accurate and will tell the pilot). If the receiver receives signal from 6 GPS sources, it is also able to exclude a faulty source, and maintain integrity of the position accuracy. This is called RAIM, and a pilot will check that RAIM is avialable as part of his pre-flight planning. Or he will do a RAIM check latest before he starts descent.
https://www.youtube.com/watch?v=DD6n-mh7Hds
Obviously if RAIM is unavailable the pilot will decide to either divert to an alternate, or use another means of navigation if available.
-
I've just checked my phone, I am where it says I am.
That would not be thanks to GPS, not unless you're in the middle of the Australian outback or the Sahara desert. Both big players on the mobile phone OS market rely on non-GPS data to get your location. Wi-Fi access points are currently the most useful data points for urban areas, and mobile phone networks are a common source for less densely populated zones (possibly because Wi-Fi access points and mobile phone towers are not allegedly zooming through space).
https://en.wikipedia.org/wiki/Wi-Fi_positioning_system
https://en.wikipedia.org/wiki/Hybrid_positioning_system
And, shockingly enough, if you check your phone somewhere that doesn't rely on WPS or mobile network towers, your location data becomes quite inaccurate.
So either:
There's another global conspiracy by people who pretended they launched GPS satellites and other people pretending that GPS works by satellites, all to keep this very important secret that the earth is actually flat safe, because obviously it's very important that this truth is kept from the general public.
Or...GPS works exactly how it's stated it works, because we live on a globe.
Third option: You're not as tech-literate as you think you are and you fallaciously assume that GPS data is the only dataset used in mobile phone location tracking. You're attributing the efficacy of big data and very recent developments in fingerprinting to a rather simple system that's been conceived of 40 years ago. Round or flat, that ain't how it works.
You are confused between the mobile phone companies establishing where a mobile is and the user of a phone establishing their location.
Please give details of phones that use anything other than GPS to show the user their location.
-
I've just checked my phone, I am where it says I am.
That would not be thanks to GPS, not unless you're in the middle of the Australian outback or the Sahara desert. Both big players on the mobile phone OS market rely on non-GPS data to get your location. Wi-Fi access points are currently the most useful data points for urban areas, and mobile phone networks are a common source for less densely populated zones (possibly because Wi-Fi access points and mobile phone towers are not allegedly zooming through space).
https://en.wikipedia.org/wiki/Wi-Fi_positioning_system
https://en.wikipedia.org/wiki/Hybrid_positioning_system
And, shockingly enough, if you check your phone somewhere that doesn't rely on WPS or mobile network towers, your location data becomes quite inaccurate.
So either:
There's another global conspiracy by people who pretended they launched GPS satellites and other people pretending that GPS works by satellites, all to keep this very important secret that the earth is actually flat safe, because obviously it's very important that this truth is kept from the general public.
Or...GPS works exactly how it's stated it works, because we live on a globe.
Third option: You're not as tech-literate as you think you are and you fallaciously assume that GPS data is the only dataset used in mobile phone location tracking. You're attributing the efficacy of big data and very recent developments in fingerprinting to a rather simple system that's been conceived of 40 years ago. Round or flat, that ain't how it works.
You are confused between the mobile phone companies establishing where a mobile is and the user of a phone establishing their location.
Please give details of phones that use anything other than GPS to show the user their location.
He's right on that mobile phones utilize not only GPS for estimating the location they show to the user, this is generally referred to as "Assisted GPS" as far as I know.
However that fact doesn't matter at all and is a pure strawmannery on Pete's part.
There are plenty of devices that rely solely on GPS and don't even have cellular or WiFi connectivity built in to do otherwise.
And no, Pete, a gyroscope, accelerometer and magnetometer can't be used to determine one's initial position. Those sensors can only help determine a change of position, as someone already pointed out.
And no, those devices don't prompt you to enter coordinates every time you turn them on.
-
Allow me to remind everyone that the key contention here is whether GPS works well or not. Not whether or not it exists. Accounts along the lines of Stinky's "I used it and it almost told me where I was!" are unlikely to swing it in either direction.
No Pete, that is not the key contention. That is the strawman you're trying to build because you can't actually explain away the OP's actual question.
From OP:
Could we now please proceed to the essential part of my question?
My intention was not to spark a debate about the accuracy of GPS, and I deliberately left open whether those systems rely on satellites (which obviously I and most fellow round-earthers have no reason to doubt) or something else like ground-based radio beacons like some flat-earthers claim.
What I was getting at was why flat-earthers think it reasonable to claim that NASA and other space agencies are not aware of the shape of earth.
You admit it exists, so you're really close to seeing that the world is, in fact, round. Ground-based GPS wouldn't work for several reasons.(range, elevation calcs, no coverage in the oceans) Satellites don't work in FEH. Even if they could orbit your little Sun, the gravitational perturbations would not result in the nice, steady orbits we see. Beyond OP's question, I'd love to know how you think GPS works.
-
No Pete, that is not the key contention.
Right. The two FE'ers that responded to this thread disagree with you on that matter. To me, that makes it a key contention. If you're not interested in the FE'ers perspective, that honestly does not bother me, but... why would you bother asking your question to the Flat Earth Society? If you just want to talk about how right you are, why not take it to Reddit?
Ground-based GPS wouldn't work for several reasons.
Indeed, it would work very poorly, and it would perform much better in some areas than others. This is exactly why it's relevant to discuss the situations in which it works very poorly, and the criteria under which GPS is generally avoided as the main source of positioning data.
-
why would you bother asking your question to the Flat Earth Society? If you just want to talk about how right you are, why not take it to Reddit?
Your forum invites the general public to converse, right here. It's in the text under the Forum link on the homepage. If you don't really want to have these conversations, should the homepage not read differently?
This is exactly why it's relevant to discuss the situations in which it works very poorly, and the criteria under which GPS is generally avoided as the main source of positioning data.
To which criteria or situations do you refer?
-
Sorry, but asserting that GPS doesn't work well in all locations where the receiver reports a workable signal is a dead-end road. Most of the anecdotal data regarding the not-working GPS involves the maps loaded into the navigation unit (aka not GPS), general complaining about things, human error, etc... It's well known that GPS-guided precision munitions hit their targets pretty well (otherwise it would be a colossal waste of money to make them). Also, can't you try this yourself? Get a GPS unit + Arduino/Raspberry Pi, take it to a known landmark, and get it to give you a fix? What about the personal locator beacons that mariners depend on when they run into trouble? The ELTs carried on aircraft?
-
Right. The two FE'ers that responded to this thread disagree with you on that matter. To me, that makes it a key contention. If you're not interested in the FE'ers perspective, that honestly does not bother me, but... why would you bother asking your question to the Flat Earth Society? If you just want to talk about how right you are, why not take it to Reddit?
You seem to have had some bad experiences on Reddit. You should avoid it. I don't post there and all of my FEH stuff is limited to this site.
Indeed, it would work very poorly, and it would perform much better in some areas than others. This is exactly why it's relevant to discuss the situations in which it works very poorly, and the criteria under which GPS is generally avoided as the main source of positioning data.
Terrific, would you mind pointing out where it works poorly that is inconsistent with its design? Poor performance is expected around tall buildings, under heavy cover, in deep canyons, etc. If you were in a nice open field and the system consistently said you were in the ocean, that would be an issue. But given the fact that the system suffers from the exact problems one would expect from a satellite-based system, it makes some sense to conclude that it is, indeed, satellite-based.
-
The two FE'ers that responded to this thread disagree with you on that matter. To me, that makes [the question whether GPS works well or not] a key contention.
Pete, understand your question. Would you agree with me that GPS works well in Aviation? Please read my post 8 posts up and comment what you think. I would be very interested if you thought that GPS didn't work well in aviation and explained why you thought it doesn't work well in aviation. If fact, realise that I'm putting my life in the hands of a GPS system when I descend between mountains in cloud at night, so if you have any concerns it doesn't work well, PLEASE let me know.
Also, I'm interested in what defines a 'well' working navigation system for you? It's obviously a very vague term. In the Middle Ages the way sail ships navigated worked "well", in the sixties navigation by NDB (non-directional radio beacons) worked well, or dead-reckoning. However these days we wouldn't even consider these inaccurate methods if we can avoid it. Having said that, dead-reckoning is surprisingly fun and accurate if you do it right!
Also Pete, are you aware that GPS is used in various applications to generate an extremely precise time? A good GPS receiver is able to produce a time that is accurate to within approximately 10 ns (nano-seconds or 0.00000001 second) of Universal Time, only based on the radio signals it receives. I have personally played with this to try to synchronise the signal of two FM radio station antennas that were in separate locations. Another interesting application is the Obstacle Lights on wind turbines that generate electricity. In some wind turbine farms you can notice that all the obstacle lights on top of these wind turbines flash at the exact same moment. They use GPS as their time base.
It's well known that GPS-guided precision munitions hit their targets pretty well (otherwise it would be a colossal waste of money to make them).
Not entirely true. Some of these use ground scanning techniques to help their navigation. For example Terrain Contour Matching. If you were the enemy and you knew these missiles were GPS guided, what would YOU do? ... jam the GPS frequency at 1575.42 MHz and 1227.60 MHz of course!
Most of the anecdotal data regarding the not-working GPS involves the maps loaded into the navigation unit (aka not GPS), general complaining about things, human error, etc..
I think it's also because of cheap receivers, I mean most people nowadays base their GPS experience on their iPhone/Samsung, which is a consumer device not specifically built for GPS. Having said that, if you have ever used the Google Maps or Apple Maps app for real-time navigation, it is still very, very impressive. Particularly using the Google Maps app with the photographic ('sattelite') maps during driving really looks like you are having a drone flying behind you that is generating a live video feed. Have you ever tried it?
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
That's a misconception.
The GPS system (those satellites etc.) is build to give you your current position, nothing more.
Distances are measured on charts. Or if you already have two positions, you could calculate the distance, offline, no GPS system needed.
These are additional features, that are build into GPS devices: Calculate distances between positions, or more convenient, nowadays most GPS devices have a build in electronic chart, so you can choose positions from this chart.
If tracking or odometer functions are not reliable, than this is an issue of these devices, not of the GPS system.
-
If fact, realise that I'm putting my life in the hands of a GPS system when I descend between mountains in cloud at night, so if you have any concerns it doesn't work well, PLEASE let me know.
That depends on the mountains. If you're happy with 0.5km-1km accuracy, you're probably good to go. You should remember that, for obvious reasons, GPS precision will drop dramatically as you approach the mountain. That said, I wouldn't take the advice of some random techie on an Internet forum in a potentially life-threatening situation, nor would I ever ask for it. Please note that I will not mourn you if you crash yourself into a mountain by blindly trusting a machine.
Also Pete, are you aware that GPS is used in various applications to generate an extremely precise time?
"Extremely precise" is an overstatement, and your figures appear to have been sourced from the Moon, but yes, synchronising your receiver's clock with the GPS is generally a pre-requisite for GPS working at all. If I were you, I'd propose NTP for a much more practical source of time.
Also, I'm interested in what defines a 'well' working navigation system for you?
The contention we're currently discussing has been outlined within the first two posts of the thread.
-
That depends on the mountains. If you're happy with 0.5km-1km accuracy, you're probably good to go.
Sorry, but I think you are deliberately minimizing my point and I'm not sure why? GPS is approved as primary source of air navingation (I can provide links to legal texts if you like) Four billion air passengers are happy with this. 4,000,000,000 passengers with zero deaths in commercial passenger jets last year. Would you agree with me that GPS works well in Aviation?
You should remember that, for obvious reasons, GPS precision will drop dramatically as you approach the mountain.
This is actually untrue and contrary to Flat Earth Empirical Evidence guidelines. The alternative means of navigation are: Non-Directional Beacons (NDB), or VOR's. They are proven to drop dramatically in precision as you approach the mountain, where as GPS maintains it accuracy as proven in aviation.
"Extremely precise" is an overstatement, and your figures appear to have been sourced from the Moon, but yes, synchronising your receiver's clock with the GPS is generally a pre-requisite for GPS working at all. If I were you, I'd propose NTP for a much more practical source of time.
Please as fellow Flat Earther I can't believe what you say. You say 10ns is overstated as "Extremely precise", but you advise using NTP with has an accuracy of 1 ms at best??? You seem to be clever in other posts, why this statement?
No, I'm not talking about the Moon, as Flat Earther I don't believe we can get to the moon. I'm talking about a receiver that I have done some work with and empirically determined to work. An current example is this receiver that gives 15 ns accuracy:
http://www.trimble.com/Timing/RES-SMT-360.aspx (http://www.trimble.com/Timing/RES-SMT-360.aspx) that you can buy here quite cheap: https://novotech.com/Products/gps-timing/Trimble/modules (https://novotech.com/Products/gps-timing/Trimble/modules)
Pete, are you aware that GPS is used in various applications to generate an extremely precise time?
Also, I'm interested in what defines a 'well' working navigation system for you?
The contention we're currently discussing has been outlined within the first two posts of the thread.
No, you said the contention was if GPS works well or not. I'll quote:
Allow me to remind everyone that the key contention here is whether GPS works well or not.
So I ask you, what defines a 'well' working navigation system for you? It's obviously a very vague term. In the Middle Ages the way sail ships navigated worked "well", in the sixties navigation by NDB (non-directional radio beacons) worked well, or dead-reckoning. However these days we wouldn't even consider these inaccurate methods if we can avoid it.
-
If fact, realise that I'm putting my life in the hands of a GPS system when I descend between mountains in cloud at night, so if you have any concerns it doesn't work well, PLEASE let me know.
That depends on the mountains. If you're happy with 0.5km-1km accuracy, you're probably good to go. You should remember that, for obvious reasons, GPS precision will drop dramatically as you approach the mountain. That said, I wouldn't take the advice of some random techie on an Internet forum in a potentially life-threatening situation, nor would I ever ask for it. Please note that I will not mourn you if you crash yourself into a mountain by blindly trusting a machine.
Also Pete, are you aware that GPS is used in various applications to generate an extremely precise time?
"Extremely precise" is an overstatement, and your figures appear to have been sourced from the Moon, but yes, synchronising your receiver's clock with the GPS is generally a pre-requisite for GPS working at all. If I were you, I'd propose NTP for a much more practical source of time.
Also, I'm interested in what defines a 'well' working navigation system for you?
The contention we're currently discussing has been outlined within the first two posts of the thread.
GPS is used in many timing applications. It is very accurate.
NTP may be a much more practical source of time in some cases but is dependent on transmission though networks and routers.
Where do you find a 0.5km accuracy with GPS, how many satellites would you be tracking?
-
Would you agree with me that GPS works well in Aviation?
For a definition of "well" that's utterly irrelevant to the subject matter here, yes. I do note that you immediately backtracked from daredevil mountain stunts to civil aviation, though.
This is actually untrue
Well, then you disagree with the creators of GPS. Can't help you there.
You say 10ns is overstated as "Extremely precise"
No, I say that 10ns is an overstated figure.
but you advise using NTP with has an accuracy of 1 ms at best???
Again, no. I suggest NTP as a much more practical source of time. And, again, you decided to fudge the numbers in your favour.
You seem to be clever in other posts, why this statement?
Because you didn't strawman them to hell and back.
No, I'm not talking about the Moon
Neither am I.
Pete, are you aware that GPS is used in various applications to generate an extremely precise time?
I already answered this question. Asking it again is unlikely to help.
So I ask you, what defines a 'well' working navigation system for you? It's obviously a very vague term. In the Middle Ages the way sail ships navigated worked "well", in the sixties navigation by NDB (non-directional radio beacons) worked well, or dead-reckoning. However these days we wouldn't even consider these inaccurate methods if we can avoid it.
This is also a question I already answered. The contention is covered within the first two posts of this thread. You can pick one of the two sides presented there, or introduce your own.
-
GPS is used for timing in broadcasting and communications because it is more accurate and reliable compared with NTP.
-
Pete, I have no idea where you got an accuracy of 500m-1km from
GPS is way more accurate than that.
https://www.gps.gov/systems/gps/performance/accuracy/
Tom's post about problems in GPS are all about GPS being used for something which it isn't primarily designed for.
If GPS is only accurate to within a 4.9m radius then if you're travelling then, over time, those inaccuracies will add up.
This has been explained. If you want to know the difference between A and Z and GPS can tell you the location of each to within a 4.9m radius then the overall accuracy will be pretty good (if A and Z are reasonably far apart, if they're 5m apart then not so much).
If you take readings ever so often so you're measuring the distance from A to B, B to C, C to D...Y to Z then each of those small inaccuracies will add up.
That does NOT mean that GPS - the P is for Positioning, it's primary purpose is to tell you your position - is in itself inaccurate.
Were this a navigation forum we could continue to argue the toss about how accurate it is, but it isn't.
In any case, it is widely used and it works using a fleet of satellites orbiting our globe, or so it is claimed.
Do you have any evidence that this is not the case? If you don't then it's another nail in the coffin of flat earth theory.
-
As this is an argument about the existence of GPS, and not accuracy, my family's old(Last used 3 years ago, so not too old) GPS will be the hammer for this nail in the TFES's coffin. Our old GPS consistently told us where we were when the cell phones couldn't, but that isn't all. It also showed us where the satellites it was getting information from were, how many there were, how strong they were, and more. Also, why would the government lie about GPS? They would have to create millions of fake devices to keep this incredibly important secret. GPS exists, and it works too.
-
As this is an argument about the existence of GPS, and not accuracy, my family's old(Last used 3 years ago, so not too old) GPS will be the hammer for this nail in the TFES's coffin. Our old GPS consistently told us where we were when the cell phones couldn't, but that isn't all. It also showed us where the satellites it was getting information from were, how many there were, how strong they were, and more. Also, why would the government lie about GPS? They would have to create millions of fake devices to keep this incredibly important secret. GPS exists, and it works too.
And there is also the Russian GPS system and others.
-
For a definition of "well" that's utterly irrelevant to the subject matter here, yes. I do note that you immediately backtracked from daredevil mountain stunts to civil aviation, though.
For aviation, GPS is very accurate. (within 1-2 meters 95% of the time) I would submit if 1-2 meters is an issue in mountain flying, you're doing it wrong and aren't long for this world. The inaccuracy is generally introduced by the device, not GPS. Consumer level devices can get you close, industrial devices will put you within a few steps, at most. Again, highly accurate given the Earth is almost 42 million feet around.
No, I say that 10ns is an overstated figure.
You are correct. The system is accurate to within 40ns 95% of the time. Which is to say it is fantastically accurate at time frames a human can comprehend. Your NTP comment was highly overstated if you start thinking about the applications where GPS is used. NTP is great for a network, but is useless, obviously, once your connection to said network is broken. (assuming you had one to begin with)
-
Once more a circular argument ensues, bogged down in debates about the measurable accuracy and technical specifications, and avoiding the core issue - what do you think enable GPS if it is not satellites?
All the RE contributors believe GPS (however "accurate" it is) is a result of a network of satellites that allow devices to triangulate their position on the Earth. Their evidence for this are the effective operation of millions of SatNav systems, the plethora of devices on the market, the documentation, the industries, the consumer products available, individual experience of working withing GPS technology etc etc
Tom/Pete and any FE faithful - What do you think enables GPS to work, however accurate or not you might think it is?
-
Pete, I have no idea where you got an accuracy of 500m-1km from
Personal observation and experimentation, of course. That's why I encouraged others to do the same.
As this is an argument about the existence of GPS, and not accuracy
Sorry, I'm not gonna let you change the subject of this conversation.
-
Pete, I have no idea where you got an accuracy of 500m-1km from
Personal observation and experimentation, of course. That's why I encouraged others to do the same.
As this is an argument about the existence of GPS, and not accuracy
Sorry, I'm not gonna let you change the subject of this conversation.
The topic of conversation is supposed to be about the existence of GPS and whether the USAF who operate it knowingly keep the shape of the Earth secret from NASA (The wiki states NASA do not know the earth is flat - they just present it as round because they expect it to be). You seem to be indicating that it isn't what it says it is, in which case what do you think it is?
The fundamental point is about what GPS is, not the level of its accuracy. Are you afraid of answering the question?
-
Pete, I have no idea where you got an accuracy of 500m-1km from
Personal observation and experimentation, of course. That's why I encouraged others to do the same.
As this is an argument about the existence of GPS, and not accuracy
Sorry, I'm not gonna let you change the subject of this conversation.
Please provide details, this is not my experience of using GPS. We are discussing position accuracy, not distance calculations.
-
whether the USAF who operate it knowingly keep the shape of the Earth secret from NASA
No.
We are discussing position accuracy, not distance calculations.
Indeed.
-
whether the USAF who operate it knowingly keep the shape of the Earth secret from NASA
No.
We are discussing position accuracy, not distance calculations.
Indeed.
So please provide your details of where you got an accuracy of 500m-1km from. GPS receivers give the accuracy of the location.
-
whether the USAF who operate it knowingly keep the shape of the Earth secret from NASA
No.
Thanks for the response. So if the USAF are not knowingly keeping the shape secret, that follows that you believe they either don't know about the shape of the Earth or incorrectly believe it to be round. So do you think they are lying about what GPS is (because they didn't launch satellites etc.)? If so, then what do you think it is?
-
I do note that you immediately backtracked
Not, I am simply stating that GPS works well in aviation and is approved as primary means of navigation. 4,000,000,000 air passengers with zero deaths, with many approaches into mountainous terrain is something that is hard to overlook, unless one chooses to be blind, ignorant, deliberately put on too many blinkers.
You should remember that, for obvious reasons, GPS precision will drop dramatically as you approach the mountain.
This is actually untrue and contrary to Flat Earth Empirical Evidence guidelines. The alternative means of navigation are: Non-Directional Beacons (NDB), or VOR's. They are proven to drop dramatically in precision as you approach the mountain, where as GPS maintains it accuracy as proven in aviation.
Well, then you disagree with the creators of GPS. Can't help you there.
You are overconfident in alternative means of navigation (I'm not sure which you propose) and ignoring the empirically proven higher accuracy of GPS, when compared head-to-head, particularly in mountainous terrain.
but you advise using NTP with has an accuracy of 1 ms at best???
Again, no. I suggest NTP as a much more practical source of time. And, again, you decided to fudge the numbers in your favour.
No, it is extremely unpractical to use NTP as a source of time anywhere outside, on the water, in the air or anywhere remote. Further NTP is useless if you want an extremely precise time as I reiterate that is in the regions of nanoseconds. NTP simply does not offer that kind of precision where GPS does. And very cheaply too, without wires.
No, I'm not talking about the Moon
Neither am I.
Yes you brought the Moon up, and I have no idea why you brought the Moon into the discussion??? I'll quote you:
your figures appear to have been sourced from the Moon
My question is, what does the moon have to do with this as we are talking about tangible, physical Printed Circuit Board that produce a time that is accurate to within 15 ns, and can be bought very cheaply at that: https://novotech.com/Products/gps-timing/Trimble/modules (https://novotech.com/Products/gps-timing/Trimble/modules), specification: http://www.trimble.com/Timing/RES-SMT-360.aspx (http://www.trimble.com/Timing/RES-SMT-360.aspx)
Pete, are you aware that GPS is used in various applications to generate an extremely precise time?
I already answered this question. Asking it again is unlikely to help.
No you did not answer this question, all you did was post a strawman about how NTP is a "practical method". I'm happy to read between the lines and conclude that 'you are not aware that GPS is used in various applications to generate an extremely precise time'. I hope I have brought some awareness and I have pointed to a cheap product that will enable you to see it for yourself, should you wish to do so. As Flat Earthers we always would like to determine the facts for ourselves, but to refuse to establish the facts even if there are cheap methods available, that is simply being flippant about our cause.
So I ask you, what defines a 'well' working navigation system for you? It's obviously a very vague term. In the Middle Ages the way sail ships navigated worked "well", in the sixties navigation by NDB (non-directional radio beacons) worked well, or dead-reckoning. However these days we wouldn't even consider these inaccurate methods if we can avoid it.
This is also a question I already answered. The contention is covered within the first two posts of this thread. You can pick one of the two sides presented there, or introduce your own.
This is again flippant towards proper Flat Earth empirical principles. It is not about choosing sides at all. I almost can't believe you saying this because you seem like a true FE-er to me. What it is about is determining the facts for ourselves, and therewith the undeniable truth.
-
Pete, I have no idea where you got an accuracy of 500m-1km from
Personal observation and experimentation, of course. That's why I encouraged others to do the same.
Found some random sign put up by the government. Was called Commemorative Permanent Survey Mark. Being proper flat earther of course decided to experiment to see what is was about. After all our knowledge is gained by what we see and observe, nothing otherwise.
Sign
(https://preview.ibb.co/hV3gxS/sign.jpg) (https://ibb.co/nsOQP7)
Permanent mark in ground
(https://preview.ibb.co/gY1OBn/permanent_mark.jpg) (https://ibb.co/iDLuHS)
Sign says
Latitude South 17° 16' 06.42" Longitude East 145° 29' 39.21"
(https://preview.ibb.co/esS8cS/sign4.jpg) (https://ibb.co/jGWZHS)
Mobile phone says
Latitude South 17° 16' 06.40" Longitude East 145° 29' 39.13" Using app called theodolite (https://itunes.apple.com/au/app/theodolite/id339393884?mt=8). Great
Difference between those points is 2.4m using simple mathematics according to this website (https://www.movable-type.co.uk/scripts/latlong.html)
Also checked with app called Commander Compass (https://itunes.apple.com/app/commander-compass/id333235419?mt=8&pt=266250&at=11lLc7&ct=w.cc)
(https://preview.ibb.co/mFauHS/cc.png) (https://ibb.co/dPuArn)
Says 17°16'06" South, East 145°29'39"
No worries. Very accurate as I know from aviation, but nevertheless interesting. A device in our pocket that tells us our position to 2.4m accurate to some random sign put up by the government. That is quite something.
Flat Earth or not I think we can all agree there is no device that will tell us our position more accurate that a gps device. Now how it works...? Round Earth says satellites. Flat Earth says I don't know.
-
Being proper flat earther of course decided to experiment to see what is was about.
Your schtick is extremely transparent, as always. Nobody is questioning that GPS works in certain areas, and that it can, on occasion, be accurate.
Flat Earth or not I think we can all agree there is no device that will tell us our position more accurate that a gps device
No, we won't agree on that. I already named methods which are far more accurate in most contexts (and which, coincidentally, you keep using and misattributing to GPS - your iPhone 7 is a poor choice of equipment for this discussion).
-
Your schtick is extremely transparent, as always. Nobody is questioning that GPS works in certain areas, and that it can, on occasion, be accurate.
Would you mind telling us where, beyond the obvious non-line of sight to the sky, GPS doesn't work? Also, can you show GPS being inaccurate more often than it is accurate? You make a ridiculous claim, would love to see some data on it. Otherwise, it is just your uninformed opinion.
-
I use GPS almost every day of my life.
At work, on my ship we use multiple receivers, not always linked together, and the accuracy is very very good. Within 10m.
We have professional units, 2 independent units, we also have units in our comms systems, and speed logs, as well as in our echo sounder, and distress systems. All work just fine, ALL the time.
Our units also detect RAIM, and will track upwards of 12 satellites, giving azimuth and elevation, signal strength and health of each sat.
As water covers just about 70% of the planet, and i have been to an awful lot of it, (except high arctic) I find it works extremely well over water, and by definition that is over the vast majority of the planet. I would be interested to know where over particular places it does not work well?
Considering we can be thousands of miles from the nearest cell phone tower, I am pretty confident that they do not use cell phone signals to provide a position, and guess what? My cell phone (with weeks of not receiving a signal) with no WiFi or data or internet can tell me where i am on the ocean pretty well as well, so i do not dispute its accuracy.
We use ECDIS (electronic charts) with Primary and secondary means of position fixing as GPS, we do not carry Loran, Decca, ( in fact they were decommissioned years ago) but we can put in manual positions from radar fixes (only good if you are within 24 miles or so of land) and celestial observations.
Millions of ships use the same systems.
If they are not accurate why do we not go aground or hit things more often?
Also how do we find our position in the middle of the ocean?
I have yet to see radio beacons in the ocean, and am pretty certain we would keep on bumping into them if they were there, and uncharted and unlit at night. Yes we do navigate at night, and No we dont have headlights.......
The question remains from the OP,
HOW DOES GPS WORK?
-
Would you mind telling us where, beyond the obvious non-line of sight to the sky, GPS doesn't work?
No - I'm not interested in defending things I didn't claim in the first place.
You make a ridiculous claim, would love to see some data on it.
I already provided an explanation of how positioning systems work in relatively populated areas. I can't help you "see" it any more than that.
-
I already provided an explanation of how positioning systems work in relatively populated areas. I can't help you "see" it any more than that.
No, you tried to obfuscate the issue. Yes, cell phones do augment GPS data, so we should throw that out. While we are at it, let's ditch cell phones all together. Let's focus on GPS devices in remote areas. They work and are extremely accurate. No way to muddy those waters. Unless you can show them being wholly inaccurate a large percentage of the time, your claim is mere opinion.
-
While we are at it, let's ditch cell phones all together. Let's focus on GPS devices in remote areas.
Thanks. Geez, that took a struggle for you to concede.
your claim is mere opinion.
Indeed. All I can offer you is my experience and empirical inquiry - and I care little for anything else. You are welcome to discard it carte blanche, but you'll achieve nothing other than stalling the conversation.
-
Would you mind telling us where, beyond the obvious non-line of sight to the sky, GPS doesn't work?
No - I'm not interested in defending things I didn't claim in the first place (...)
(...) Nobody is questioning that GPS works in certain areas, (...)
-
While we are at it, let's ditch cell phones all together. Let's focus on GPS devices in remote areas.
Thanks. Geez, that took a struggle for you to concede.
your claim is mere opinion.
Indeed. All I can offer you is my experience and empirical inquiry - and I care little for anything else. You are welcome to discard it carte blanche, but you'll achieve nothing other than stalling the conversation.
And i offered my empirical evidence, or observations over the last 20+ years of using GPS at sea. Where the overwhelming majority of the world it works just as it should, and very well thank you.
It calculates distances very well, and speeds accurately (to as good as 0.1Knot) so it works, some ships even use it as a back up to a compass. The position of the bow and the position of the bridge are taken with different antennas and the bearing between them is calculated, giving the heading. They are permitted under international maritime Organisation rules. And they work!
BUT if satellites are not in orbit HOW does it all work? A basic principle would be nice, other than radio masts, or some other generic statement, at least a basic principle;e would give me some understanding.
4 pages of posts and still no one is able to offer an explanation other than the official explanation of time difference between the satellite and the receiver. That gives one position line (actually a circle) but give 2 satellites, and you get an intersection of the lines (hopefully) well 2 intersections, 3 satellites, more intersections, eventually resolving more and more accurately the position.
That’s the “official” line.
If there are no satellites, how do my magic boxes spit out positions, and range and bearing to other positions, as well as a whole host of other things.
-
[quoting me back]
My apologies - I forgot that you guys will jump at even the smallest error in phrasing. Of course, I intended to remain consistent in my assertion that GPS doesn't work well in certain areas. I elaborated on this quite a lot, and so it should be rather easy to infer. But hey, congratulations, at the low-low cost of outing yourself as intellectually dishonest, you got one up on me.
And i offered my empirical evidence, or observations over the last 20+ years of using GPS at sea.
That's okay. You are more than welcome to have your own opinion. It appears to be irreproducible, and thus I won't pay much attention to it, but I also won't try to convince you otherwise.
That said, given the trend of """sailors""" who come here, I reserve my right to doubt that you're the first one here not to lie about your experience.
-
You are waiting since 4 pages of discussion for an answer, because there can't be an answer. GPS is a quite straight forward, coherent concept. In the best case you can get some alternative explanations that work in some special areas, e.g. for cities and so on. But you will never be able to find a equivalent coherent explanation.
But that's the fundamental problem of the whole flat earth idea. Of course you can always find alternative explanations for certain aspects, but they soon start to contradict each other and then you have to introduce more and more assumptions. In the end the whole idea is based on a single observation, that the earth looks flat if you are looking out of your window. That's all. But already if you look out of your window and you try to imagine how a hypothetical flat earth would look, you would notice that it would be quite different from what you actually see.
The core challenge for a flat earth believer is to find explanations why a flat earth looks like a round earth, and everything that exist on this flat earth behaves like the earth would be round. You have to twist and bend everything so that it fits, but can't. If you solve one problem, another appears. It's for the same reason you have so many different types of maps, you cannot transform a 3D object into a 2D one without distortions. You can find a suitable solution for a map, that represents a certain aspect quite well and another that fits better to something else.
And that's not only true for maps. Everything works different, looks different and is experienced differently on a 3D world compared to a (functional) 2D world.
-
[quoting me back]
My apologies - I forgot that you guys will jump at even the smallest error in phrasing. Of course, I intended to remain consistent in my assertion that GPS doesn't work well in certain areas. I elaborated on this quite a lot, and so it should be rather easy to infer. But hey, congratulations, at the low-low cost of outing yourself as intellectually dishonest, you got one up on me. (...)
That wasn't my intention at all. I just wanted to point out the reason why StinkyOne asked you what he asked.
Sorry for this misunderstading, I probably didn't express myself clearly enough. I'll try to correct that next time.
-
[quoting me back]
My apologies - I forgot that you guys will jump at even the smallest error in phrasing. Of course, I intended to remain consistent in my assertion that GPS doesn't work well in certain areas. I elaborated on this quite a lot, and so it should be rather easy to infer. But hey, congratulations, at the low-low cost of outing yourself as intellectually dishonest, you got one up on me.
And i offered my empirical evidence, or observations over the last 20+ years of using GPS at sea.
That's okay. You are more than welcome to have your own opinion. It appears to be irreproducible, and thus I won't pay much attention to it, but I also won't try to convince you otherwise.
That said, given the trend of """sailors""" who come here, I reserve my right to doubt that you're the first one here not to lie about your experience.
[quoting me back]
My apologies - I forgot that you guys will jump at even the smallest error in phrasing. Of course, I intended to remain consistent in my assertion that GPS doesn't work well in certain areas. I elaborated on this quite a lot, and so it should be rather easy to infer. But hey, congratulations, at the low-low cost of outing yourself as intellectually dishonest, you got one up on me.
That said, given the trend of """sailors""" who come here, I reserve my right to doubt that you're the first one here not to lie about your experience.
You seem to insult my professional integrity? I am who i say i am, i have posted my credentials, and also note that i said i am a seafarer, NOT Sailor. We are a different breed. I work for a living, and have no reason to lie. I dont need to, All i have posted on these boards has been direct observations or direct experiences.
Your limited experience with GPS does not seem to qualify you are a heavy user of the equipment, and most likely not seen it work in as many places as myself, and as it is a part of my professional life, so Iwill pretty much be able to discount your comments, as you seem to pay none to others experiences.
So removing Petes unsubstantiated and most likely amateurish is of GPS, then the we can get back on track and try to determine how GPS works?
Or are we going to get a few more insults thrown around to try to push the thread off topic?
-
Pete, I have no idea where you got an accuracy of 500m-1km from
Personal observation and experimentation, of course. That's why I encouraged others to do the same.
As this is an argument about the existence of GPS, and not accuracy
Sorry, I'm not gonna let you change the subject of this conversation.
I have a number of GPS receivers and car satnavs show their location accurately on roads, not 1km out.
-
My apologies - I forgot that you guys will jump at even the smallest error in phrasing.
This made me laugh. You literally DMed me once because I misspelled a word. Turnabout is fair play and all that.
Thanks. Geez, that took a struggle for you to concede.
What did I concede? I never argued that cell phones didn't supplement their GPS data. That can be pretty important if you don't have line of sight to the sky. I said let's take them out of the mix because you're trying to use them as a straw man of sorts. You're arguing a losing position. We all know GPS works very well. You can try to cast doubt on that, but it isn't reality. Then again, neither is a flat Earth and you're still trying to defend that so maybe you're just a contrarian?
-
...., some ships even use it as a back up to a compass. The position of the bow and the position of the bridge are taken with different antennas and the bearing between them is calculated, giving the heading. They are permitted under international maritime Organisation rules. And they work!
That's interesting. It was in my early GPS days, also some 20+ years ago, when I thought, GPS derives speed and heading from two consecutive measures of position. Meanwhile I learned, GPS not only calculates the position with one measure, using doppler shift it also calculates speed and heading, very accurate. The measure of doppler shift is integral part of the position calculation, as the receiver(s) have to be tuned for the variance in frequency of the incoming signal, due to high speed of the satellites.
Maybe this "two GPS device setup" has something to do with redundancy and the measure of the bearing between those two antennas is a plausibility check.
Thinking about it again (I've only sailed yachts), now I got it: One GPS alone will only show course/track over ground not the direction of the keel (true course).
-
you keep using and misattributing to GPS - your iPhone 7 is a poor choice of equipment for this discussion
Thank you for allowing me to clarify my point. It helps me think more clearer and I will incorporate your thoughts as follows:
(p.s. mobile phone was in Aeroplane Mode the whole time, so not communicating with networks. Do you know what means Aeroplane mode?)
Flat Earth or not I think we can all agree that, there is no device that will tell us our position more accurate than a gps device. Even a poor choice of gps device gets position within 2.4m of random government sign. Now how it works...? Round Earth says satellites. Flat Earth says I don't know.
Your schtick is extremely transparent, as always. Nobody is questioning that GPS works in certain areas, and that it can, on occasion, be accurate.
Who says schtick? You are clever enough to dig through metadata of my picture to uncover it was taken by an iPhone 7, but dumb enough to not know that gps is:
- accurate to be approved primary means of navigation in aviation world wide. Four billion air passengers (4,000,000,000) with zero deaths in commercial passenger jets last year, with planes descending at night, in between mountains using only GPS every day.
- used in millions of ships as primary means of navigation as we have just found out thanks to Tontogary
- working well in each of the billions of mobile phones world wide.
I suspect another case of not following real flat earth principles. Pity, because that is not how our knowledge gets increased. Seeing, observing, continually gaining knowledge.
I never argued that cell phones didn't supplement their GPS data.
This why I put my device in Aeroplane mode, so it would just get position with gps, not communicate with any networks to get more data.
-
I don't know why there is so much argument about how accurate GPS is.
Isn't the point that it does demonstrably work.
The only debate relevant to the FES is whether it could work without satellites and, if it could, why this is another big conspiracy to pretend that it does work with satellites.
-
I don't know why there is so much argument about how accurate GPS is.
Uber is certainly leaving this debate in their wake.
They say they know where satellites are at any given time. Then they use newly gathered 3D maps of cities to figure out which satellites the device can see directly, which are blocked. This results in improved positioning, which is important for them in their business model.
(https://eng.uber.com/wp-content/uploads/2018/04/image8-768x432.jpg) (https://eng.uber.com/rethinking-gps/)
(https://eng.uber.com/wp-content/uploads/2017/07/image3.gif) (https://eng.uber.com/rethinking-gps/)
By way everyone can find out position of satellites now because it is sent out every gps radio signal. Called the "Almanac".
Simple copy of current Almanac here (https://www.navcen.uscg.gov/?pageName=currentAlmanac&format=yuma-txt).
You can also buy a cheap raspberry and read NMEA-0183 data that it continually outputs on RS-232. $60 dollars here. (https://core-electronics.com.au/usb-ttl-raspberry-pi-gps-tracker.html?utm_source=google_shopping&gclid=Cj0KCQjw5fDWBRDaARIsAA5uWTivo_61hTpDXAAD0Ud_uztT8H9vsyKK1oq7D81EQiDBt8FDcGMuX60aAnwgEALw_wcB) I have done this many times not raspberry but.
Now how it works...? Round Earth says satellites. Flat Earth says I don't know.
why this is another big conspiracy to pretend that it does work with satellites.
Yes tried to find out how big conspiracy was in other thread but got shut down.
-
Another strong hint, that only satellites can build a GPS system:
GPS receivers, even "consumer level" will additionally calculate speed and heading for each position measurement.
Long ago I though, heading and speed are calculated from two consecutive measures, but as I learned that imposes great errors.
The better way is to use Doppler Shift, and this can be done within the same measure.
Due to the high speed of the sender/satellites, the signal sent has a frequency shift. Receivers continuously adjust for this frequency shift and so measure the Doppler Shift.
Actually this Doppler Shift could also be used to calculate a position of the receiver.
History, Sputnik I:
When the Soviet Union launched the first artificial satellite (Sputnik 1) in 1957, two American physicists, William Guier and George Weiffenbach, at Johns Hopkins University's Applied Physics Laboratory (APL) decided to monitor its radio transmissions. Within hours they realized that, because of the Doppler effect, they could pinpoint where the satellite was along its orbit.
Vice versa, if position of Sputnik is known, hints for the position of the receiver can be obtained.
Indeed, the first satellite based navigation systems TRANSIT was based on Doppler Shift.
-
I don't know why there is so much argument about how accurate GPS is.
Uber is certainly leaving this debate in their wake.
They say they know where satellites are at any given time. Then they use newly gathered 3D maps of cities to figure out which satellites the device can see directly, which are blocked. This results in improved positioning, which is important for them in their business model.
(https://eng.uber.com/wp-content/uploads/2018/04/image8-768x432.jpg) (https://eng.uber.com/rethinking-gps/)
(https://eng.uber.com/wp-content/uploads/2017/07/image3.gif) (https://eng.uber.com/rethinking-gps/)
By way everyone can find out position of satellites now because it is sent out every gps radio signal. Called the "Almanac".
Simple copy of current Almanac here (https://www.navcen.uscg.gov/?pageName=currentAlmanac&format=yuma-txt).
You can also buy a cheap raspberry and read NMEA-0183 data that it continually outputs on RS-232. $60 dollars here. (https://core-electronics.com.au/usb-ttl-raspberry-pi-gps-tracker.html?utm_source=google_shopping&gclid=Cj0KCQjw5fDWBRDaARIsAA5uWTivo_61hTpDXAAD0Ud_uztT8H9vsyKK1oq7D81EQiDBt8FDcGMuX60aAnwgEALw_wcB) I have done this many times not raspberry but.
Now how it works...? Round Earth says satellites. Flat Earth says I don't know.
why this is another big conspiracy to pretend that it does work with satellites.
Yes tried to find out how big conspiracy was in other thread but got shut down.
I find this fascinating. It's literally possible to point a receiver up into the sky, at a known, predicted position, and to pick up a signal. I can't think of anything that would explain this apart from there being something up in the sky. However, if there's something up in the sky, then we are dragged into the worldview of satellites and spacecraft and orbiting the Earth. So we have to say that we don't know.
If the Flat Earth is a fact, then there can't be a satellite up there. When someone points a satellite receiver up into the sky, and gets a signal, there must be some other explanation. The alternative would be that FE theory is wrong, which is impossible.
-
Nice rationalization there, but those explanations have not been demonstrated to be true. All we know is that GPS is wrong when attempting to determine distance.
You didn't even read your own link. Please explain "Survey Class GPS".
Nice try. Your fear of admitting we know anything about distance is quite obvious.