*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 10638
  • Flat Earth Believer
    • View Profile
Re: Cartography and a flat earth
« Reply #40 on: August 29, 2017, 03:19:38 PM »
Quote
We know how map projections work.

What is your explanation for why they exist? Why would we need projection for mapping if the earth is flat? Wouldn't we be able to just directly transcribe from one plane to another?

Cartographers were raised to believe that the earth is a globe and experiment with different projections to display that mistaken belief.

Using calculated distances would be as you say, "based on Round Earth lat/lon coordinate devices".

But using logged flight times is not calculated at all.  It is very simple, historical data.  It isn't based on a compass or a GPS, it isn't round or flat data. It is just how long it takes to get from place to place.

They also need to know the distance between those points in order to compute their average speed.

Airspeed-only instruments are inaccurate and not used in navigation, as it is difficult to measure the speed of fluids traveling within fluids.
He's not using speed at all though. Miles don't enter into the equation. He's going to use the flight times as an impromptu 'unit of measure' for his wires. I would presume something like 1 inch = 1 hour. Distance is removed entirely from the equation, and since one can reasonably assume all planes of the same type fly the same speed, the proportions will all be the same.

On that note JHelzer, make sure you're pulling all flight times from the same airline, preferably doing your best to double check they are all done with the same plane model. I believe Qantas was used before as their entire intercontinental fleet is the same model of plane.

And how do you know how fast the planes fly?

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 10638
  • Flat Earth Believer
    • View Profile
Re: Cartography and a flat earth
« Reply #41 on: August 29, 2017, 03:21:08 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

Offline zp0okii

  • *
  • Posts: 33
    • View Profile
Re: Cartography and a flat earth
« Reply #42 on: August 29, 2017, 03:22:46 PM »
Quote
We know how map projections work.

What is your explanation for why they exist? Why would we need projection for mapping if the earth is flat? Wouldn't we be able to just directly transcribe from one plane to another?

Cartographers were raised to believe that the earth is a globe and experiment with different projections to display that mistaken belief.

Using calculated distances would be as you say, "based on Round Earth lat/lon coordinate devices".

But using logged flight times is not calculated at all.  It is very simple, historical data.  It isn't based on a compass or a GPS, it isn't round or flat data. It is just how long it takes to get from place to place.

They also need to know the distance between those points in order to compute their average speed.

Airspeed-only instruments are inaccurate and not used in navigation, as it is difficult to measure the speed of fluids traveling within fluids.
He's not using speed at all though. Miles don't enter into the equation. He's going to use the flight times as an impromptu 'unit of measure' for his wires. I would presume something like 1 inch = 1 hour. Distance is removed entirely from the equation, and since one can reasonably assume all planes of the same type fly the same speed, the proportions will all be the same.

On that note JHelzer, make sure you're pulling all flight times from the same airline, preferably doing your best to double check they are all done with the same plane model. I believe Qantas was used before as their entire intercontinental fleet is the same model of plane.

And how do you know how fast the planes fly?


>>> But you said map projections work! The quote is right up there - map projections wouldn't "work" if the earth were flat, because the projection would require no refraction!

Re: Cartography and a flat earth
« Reply #43 on: August 29, 2017, 03:27:11 PM »
Using calculated distances would be as you say, "based on Round Earth lat/lon coordinate devices".

But using logged flight times is not calculated at all.  It is very simple, historical data.  It isn't based on a compass or a GPS, it isn't round or flat data. It is just how long it takes to get from place to place.

They also need to know the distance between those points in order to compute their average speed.

Airspeed-only instruments are inaccurate and not used in navigation, as it is difficult to measure the speed of fluids traveling within fluids.
He's not using speed at all though. Miles don't enter into the equation. He's going to use the flight times as an impromptu 'unit of measure' for his wires. I would presume something like 1 inch = 1 hour. Distance is removed entirely from the equation, and since one can reasonably assume all planes of the same type fly the same speed, the proportions will all be the same.

On that note JHelzer, make sure you're pulling all flight times from the same airline, preferably doing your best to double check they are all done with the same plane model. I believe Qantas was used before as their entire intercontinental fleet is the same model of plane.

And how do you know how fast the planes fly?
That's the thing. It doesn't matter how fast they fly. He's not doing anything with that information. He's using the average flight times as 'distance' instead.

*

Offline CriticalThinker

  • *
  • Posts: 159
  • Polite and Pragmatic
    • View Profile
Re: Cartography and a flat earth
« Reply #44 on: August 29, 2017, 03:38:39 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

https://en.m.wikipedia.org/wiki/Doppler_effect

This is how the Doppler effect measures speed and I provided the peer reviewed research article testing the accuracy of flight speed using radar in the flight times thread. Doppler radar is calibrated using a flat metered track and stopwatch. It is also one of the multiple methods used by a single aircraft for tracking flight speed.

Thank You,

CriticalThinker
Quod gratis asseritur, gratis negatur

*

Offline Rounder

  • *
  • Posts: 780
  • What in the Sam Hill are you people talking about?
    • View Profile
Re: Cartography and a flat earth
« Reply #45 on: August 29, 2017, 03:39:24 PM »
Cartographers were raised to believe that the earth is a globe and experiment with different projections to display that mistaken belief.
Once the round earth was understood and accepted, early cartographers initially thought the sphere was perfect.  They measured it, found it to be not perfect, and accepted a change in knowledge.  You imply here (and in many other posts) that once a thing is learned it can never change; that assertion is false.  Perhaps for a Zetetic that assertion is true, but not for people using the scientific method.
Proud member of İntikam's "Ignore List"
Ok. You proven you are unworthy to unignored. You proven it was a bad idea to unignore you. and it was for me a disgusting experience...Now you are going to place where you deserved and accustomed.
Quote from: SexWarrior
You accuse {FE} people of malice where incompetence suffice

*

Offline CriticalThinker

  • *
  • Posts: 159
  • Polite and Pragmatic
    • View Profile
Re: Cartography and a flat earth
« Reply #46 on: August 29, 2017, 04:49:46 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

Tom,

The next time that you get a speeding ticket, please try to fight the accuracy of Doppler radar guns and let me know how it works out for you. You can't assume speed safely on the ground let alone while thousands of feet in the air. Airlines must measure speed because if the plane goes too slow it will lose lift and if it goes too fast will suffer structural failure.  Because flight speed is more important to know than flight time, it is measured using multiple methods. Doppler radar fits your demands of a system that produces accurate speed data on a flat plane.

To take a page from your book.  Please provide evidence that airlines assume speed based on a round earth model.

ThankYou

CriticalThinker

Quod gratis asseritur, gratis negatur

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 10638
  • Flat Earth Believer
    • View Profile
Re: Cartography and a flat earth
« Reply #47 on: August 29, 2017, 05:01:22 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

Tom,

The next time that you get a speeding ticket, please try to fight the accuracy of Doppler radar guns and let me know how it works out for you. You can't assume speed safely on the ground let alone while thousands of feet in the air. Airlines must measure speed because if the plane goes too slow it will lose lift and if it goes too fast will suffer structural failure.  Because flight speed is more important to know than flight time, it is measured using multiple methods. Doppler radar fits your demands of a system that produces accurate speed data on a flat plane.

To take a page from your book.  Please provide evidence that airlines assume speed based on a round earth model.

ThankYou

CriticalThinker

GPS is based on a Round Earth lat/lon coordinate system. Airplanes have GPS and other such lat/lon coordinate systems on board. Please show that airplanes are measuring their speed with their on-board doppler radar gun rather than using their navigational equipment.
« Last Edit: August 29, 2017, 05:11:43 PM by Tom Bishop »

Re: Cartography and a flat earth
« Reply #48 on: August 29, 2017, 05:05:58 PM »
If the Earth really is flat, then it would be simple to map it on a flat paper.

Go ahead and map the world for us then, if you think it is so easy.
Tom, I believe that's the point. It apparently isn't easy, ergo how can the Earth be flat.

He just said that it's easy to map the world. Why not map it for us then and then tell us the results?

Actually, it is quite easy. Just look at a globe. All the land masses – Greenland, Africa, Australia, Alaska to name a few – are correctly shaped and appropriately sized. Distances between any 2 points are consistent with GPS, airline flight times, mathematical calculations using latitude and longitude.

That is why all two-dimensional maps have shortcomings. You cannot accurately plot out a three-dimensional sphere onto a two-dimensional sheet of paper.

Looking at a globe and then assuming that the earth is a globe is your way of mapping the earth?

No,
1) You begin with the assumption that the Flat and Spherical Earth models are both equally correct.
2) Then, test each model equally by taking size, distance measurements from each model and comparing it to objective, third-party data.
3) Inconsistencies with the model and known data indicates a flaw in the model.

When tested, the 2-D Flat Earth maps show numerous inconsistencies with available data.

According to the Flat Earth Ice Wall Model presented on wiki:
   Australia is larger than North America
   South America is twice as large as North America
   Africa is larger than Asia and Europe combined.

The Flat Earth Distinct Continent Model also presented on wiki:
   Australia is larger than Africa.
   Canada is taller than it is wide.
   New Zealand is larger than Greenland.

The Spherical Earth Globe Model:
Is consistent with published data of landmass sizes and shapes.

Measured distances especially on the outer edges of both Flat Earth models differ wildly from distances measured by GPS, airline flight data and mathematically calculated with latitude and longitude coordinates. With the Spherical Earth Model there are no such inconsistencies. This point has been pointed out on numerous previous threads but has been largely ignored by the Flat Earth community.

Re: Cartography and a flat earth
« Reply #49 on: August 29, 2017, 05:20:10 PM »
If the Earth really is flat, then it would be simple to map it on a flat paper.

Go ahead and map the world for us then, if you think it is so easy.
Tom, I believe that's the point. It apparently isn't easy, ergo how can the Earth be flat.

He just said that it's easy to map the world. Why not map it for us then and then tell us the results?

Actually, it is quite easy. Just look at a globe. All the land masses – Greenland, Africa, Australia, Alaska to name a few – are correctly shaped and appropriately sized. Distances between any 2 points are consistent with GPS, airline flight times, mathematical calculations using latitude and longitude.

That is why all two-dimensional maps have shortcomings. You cannot accurately plot out a three-dimensional sphere onto a two-dimensional sheet of paper.

Looking at a globe and then assuming that the earth is a globe is your way of mapping the earth?

No,
1) You begin with the assumption that the Flat and Spherical Earth models are both equally correct.
2) Then, test each model equally by taking size, distance measurements from each model and comparing it to objective, third-party data.
3) Inconsistencies with the model and known data indicates a flaw in the model.

When tested, the 2-D Flat Earth maps show numerous inconsistencies with available data.

According to the Flat Earth Ice Wall Model presented on wiki:
   Australia is larger than North America
   South America is twice as large as North America
   Africa is larger than Asia and Europe combined.

The Flat Earth Distinct Continent Model also presented on wiki:
   Australia is larger than Africa.
   Canada is taller than it is wide.
   New Zealand is larger than Greenland.

The Spherical Earth Globe Model:
Is consistent with published data of landmass sizes and shapes.

Measured distances especially on the outer edges of both Flat Earth models differ wildly from distances measured by GPS, airline flight data and mathematically calculated with latitude and longitude coordinates. With the Spherical Earth Model there are no such inconsistencies. This point has been pointed out on numerous previous threads but has been largely ignored by the Flat Earth community.
It hasn't been ignore, Tom just keeps claiming that (essentially) a mile on a FE, and a mile on a RE are different enough that the published measurements are incorrect. But I haven't seen him say how different they are, how he knows they're different, and what method would be acceptable to him to check distances with. The last is more that I'm looking for a definitive "Yes, distances found using 'X' will be accurate" and haven't seen it. Hmm, thinking about it though, if we could find two maps made using triangulation that had the 'primary' segment labeled with the distance, we could use that to determine how different distances on it would be at the edges using trig that doesn't adjust for curvature.

*

Offline CriticalThinker

  • *
  • Posts: 159
  • Polite and Pragmatic
    • View Profile
Re: Cartography and a flat earth
« Reply #50 on: August 29, 2017, 06:10:53 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

Tom,

The next time that you get a speeding ticket, please try to fight the accuracy of Doppler radar guns and let me know how it works out for you. You can't assume speed safely on the ground let alone while thousands of feet in the air. Airlines must measure speed because if the plane goes too slow it will lose lift and if it goes too fast will suffer structural failure.  Because flight speed is more important to know than flight time, it is measured using multiple methods. Doppler radar fits your demands of a system that produces accurate speed data on a flat plane.

To take a page from your book.  Please provide evidence that airlines assume speed based on a round earth model.

ThankYou

CriticalThinker

GPS is based on a Round Earth lat/lon coordinate system. Airplanes have GPS and other such lat/lon coordinate systems on board. Please show that airplanes are measuring their speed with their on-board doppler radar gun rather than using their navigational equipment.

Tom,

Flights had to measure their speed long before GPS was invented.  They use redundant systems.  The presence of one that you won't accept does not negate the accuracy of another.  I'm getting tired of the GPS red herring.

For your reading pleasure.
Witte, TH; Wilson, AM; (2004) Accuracy of non-differential GPS for the determination of speed over ground. JOURNAL OF BIOMECHANICS , 37 (12) pp. 1891-1898. 10.1016/j.jbiomech.2004.02.031.

When GPS was tested for speed accuracy on a flat plane against a metered track and mechanical time measurement system it was accurate for measuring speed to within an outer bound of 0.4 ms−1 and a sample size of over 5000 repetitions.    Accuracy was maintained under a variety of metered track sizes, circular and straight line paths and weather conditions.  The least accurate 0.4 ms−1 was present in extremely tight turns that are too small for commercial aircraft to perform due to their physical length.

Now GPS as a methodology of tracking speed over ground has been verified within an acceptable margin of error using non-globed earth assumption testing methods.  Here's a fun fact.  GPS determines speed using the doppler shift effect too!  It doesn't use a complex lat/long equation because calculating the Doppler shift effect is much easier and very reliable.

Now it doesn't matter whether a flight records air speed using either system, they both match metered tracks on a flat plane to within an acceptable margin of error.

I am open to rebuttal.

Thank You,

CriticalThinker
Quod gratis asseritur, gratis negatur

*

Offline TomInAustin

  • *
  • Posts: 1367
  • Round Duh
    • View Profile
Re: Cartography and a flat earth
« Reply #51 on: August 29, 2017, 06:28:58 PM »
No they don't Tom as I established in the other thread.  All they need is to be able to measure the Doppler Shift Effect which doesn't rely on a known distance or any globed earth assumption.  It's based on the physics of echolocation.  When combined with a standard timepiece, distance can be calculated algebraically.

Thank you,

CritcalThinker

Provide evidence for your idea of how you think plane speed is measured. Why should we assume that they get their average air-speeds via lasers or whatever rather than assuming speeds based on Round Earth distances?

Tom,

The next time that you get a speeding ticket, please try to fight the accuracy of Doppler radar guns and let me know how it works out for you. You can't assume speed safely on the ground let alone while thousands of feet in the air. Airlines must measure speed because if the plane goes too slow it will lose lift and if it goes too fast will suffer structural failure.  Because flight speed is more important to know than flight time, it is measured using multiple methods. Doppler radar fits your demands of a system that produces accurate speed data on a flat plane.

To take a page from your book.  Please provide evidence that airlines assume speed based on a round earth model.

ThankYou

CriticalThinker

GPS is based on a Round Earth lat/lon coordinate system. Airplanes have GPS and other such lat/lon coordinate systems on board. Please show that airplanes are measuring their speed with their on-board doppler radar gun rather than using their navigational equipment.

Tom,

Flights had to measure their speed long before GPS was invented.  They use redundant systems.  The presence of one that you won't accept does not negate the accuracy of another.  I'm getting tired of the GPS red herring.

For your reading pleasure.
Witte, TH; Wilson, AM; (2004) Accuracy of non-differential GPS for the determination of speed over ground. JOURNAL OF BIOMECHANICS , 37 (12) pp. 1891-1898. 10.1016/j.jbiomech.2004.02.031.

When GPS was tested for speed accuracy on a flat plane against a metered track and mechanical time measurement system it was accurate for measuring speed to within an outer bound of 0.4 ms−1 and a sample size of over 5000 repetitions.    Accuracy was maintained under a variety of metered track sizes, circular and straight line paths and weather conditions.  The least accurate 0.4 ms−1 was present in extremely tight turns that are too small for commercial aircraft to perform due to their physical length.

Now GPS as a methodology of tracking speed over ground has been verified within an acceptable margin of error using non-globed earth assumption testing methods.  Here's a fun fact.  GPS determines speed using the doppler shift effect too!  It doesn't use a complex lat/long equation because calculating the Doppler shift effect is much easier and very reliable.

Now it doesn't matter whether a flight records air speed using either system, they both match metered tracks on a flat plane to within an acceptable margin of error.

I am open to rebuttal.

Thank You,

CriticalThinker

This topic seems to strike the most fear in the true believer.   The silly and nebulous topics of conspiracies, cosmic whirlpools, acceleration creating gravity, light bending to make sunsets, and on and on can be argued to infinity, but a topic proven with math forget it.  Can't argue the math, attack the variables.
Do you have a citation for this sweeping generalisation?

*

Offline Tom Bishop

  • Zetetic Council Member
  • **
  • Posts: 10638
  • Flat Earth Believer
    • View Profile
Re: Cartography and a flat earth
« Reply #52 on: August 29, 2017, 07:36:27 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.

Re: Cartography and a flat earth
« Reply #53 on: August 29, 2017, 07:51:37 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.
As I recall they called out the 1.9% because that is what the study author's said/claimed as the final number. This appears to be the study in question in this thread however, and if that link doesn't work try navigating to it from here instead. First should be a direct link to the study, second is a landing page for it in case the first has something that prevents a direct link working.

*

Offline TomInAustin

  • *
  • Posts: 1367
  • Round Duh
    • View Profile
Re: Cartography and a flat earth
« Reply #54 on: August 29, 2017, 08:00:05 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.

The article in question was looking at people on a bicycle going around a track.  That is not even close to the use of GPS in aviation, maritime and even cars.  Straight from the horse's mouth, GPS and WAAS "gives position accuracy of better than 3 m, 95 percent of the time".   

http://www8.garmin.com/aboutGPS/waas.html


Any discussion of GPS accuracy of 3 meters not being good enough is just lazy and ridiculous.   Why don't you just try and help settle this without your silly arguments?



Do you have a citation for this sweeping generalisation?

Re: Cartography and a flat earth
« Reply #55 on: August 29, 2017, 08:14:12 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.
You know what this was about, you are claiming not to understand the detail.

You agree the locational accuracy of GPS?  As used by the military, surveyors etc.

*

Offline CriticalThinker

  • *
  • Posts: 159
  • Polite and Pragmatic
    • View Profile
Re: Cartography and a flat earth
« Reply #56 on: August 29, 2017, 09:07:08 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.

Irrelevant.

GPS speed accuracy on a single human over extremely short distance while making pinpoint turns does not apply to vehicular motion.  Unless you're claiming that a Boeing 747 is capable of making a 90 degree turn under 3 feet in radius.  The 20% you are hanging your hat on was instantaneous very rapid acceleration after making a turn as they state in the article.  Those physics simply can't apply to commercial airlines.

The ball is in your court again Tom.

Thank you,

CriticalThinker
Quod gratis asseritur, gratis negatur

*

Offline CriticalThinker

  • *
  • Posts: 159
  • Polite and Pragmatic
    • View Profile
Re: Cartography and a flat earth
« Reply #57 on: August 29, 2017, 09:11:04 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.

Furthermore,

The researchers didn't pick the 1.9% error of margin to report.  They clearly reported all of them and stated that GPS speed monitoring wasn't yet accurate enough to calculate calorie expenditure in humans playing sports.  Airlines aren't making those kinds of maneuvers.

Thank you,

CciticalThinker
Quod gratis asseritur, gratis negatur

Offline 3DGeek

  • *
  • Posts: 1024
  • Path of photon from sun location to eye at sunset?
    • View Profile
    • What path do the photons take from the physical location of the sun to my eye at sunset
Re: Cartography and a flat earth
« Reply #58 on: August 29, 2017, 09:42:07 PM »
Can you link us to the full article? The last time we had a GPS accuracy article we saw that the authors tested a variety of different GPS devices which all showed different speed results, with an error range of over 20%, and then picked out the result closest to the result they wanted and declared that GPS was incredibly accurate, only differing from the real speed by 2%.

Irrelevant.

GPS speed accuracy on a single human over extremely short distance while making pinpoint turns does not apply to vehicular motion.  Unless you're claiming that a Boeing 747 is capable of making a 90 degree turn under 3 feet in radius.  The 20% you are hanging your hat on was instantaneous very rapid acceleration after making a turn as they state in the article.  Those physics simply can't apply to commercial airlines.

The ball is in your court again Tom.

Thank you,

CriticalThinker

The thing about GPS is that it provides a POSITION - accurate to around 10 feet (although dual antenna units get you down to 2 feet).  It's possible to "lose the signal" and wind up with insufficient satellites to get a good signal and stuff like that.

GPS doesn't give you speed (well, not directly at least).  The phone or handheld GPS receiver calculates speed by calculating distance between two Lat/Long position and dividing that distance by the time between the past readings.

Clearly for athletic events over "human" distances - this is a disaster.   If someone runs 100 feet in 10 seconds - and the GPS is "off" by 10 feet then the reading could say anything from 8 feet per second up to 12 feet per second...which is a horrific error.

However, if an airplane flies 2000 miles (10 million feet) and the GPS is off by 10 feet - then the error is at worst only 2 parts per million...utterly negligible.

So using data about the problems of measuring athletic event performance with GPS is laughably inapplicable to discussions about thousand mile journeys.

As usual, Mr Bishop is clutching at straws and hoping we're too stupid to notice!  SORRY TOM...WE'RE NOT STUPID.

Hey Tom:  What path do the photons take from the physical location of the sun to my eye at sunset?

Re: Cartography and a flat earth
« Reply #59 on: August 29, 2017, 09:45:01 PM »
Ok. I have been looking around and getting ready to start the Flight Time Map project, but have run into a bump.

I was wanting to use https://openflights.org to get flight time data, but I discovered that they just calculate the times based on distance.
In real-life this works perfectly, but I know that it will completely ruin the validity of my model in this forum.

I need times based on departures and arrivals of real passenger jets.  Please point me in the right direction to be able to find acceptable data.
Many thanks.
The hallmark of true science is repeatability to the point of accurate prediction.