#### scomato

• 175
##### Moonbounce propagation time and the distance of the Moon from Earth
« on: February 01, 2022, 02:38:36 PM »
It's possible to bounce a radio wave off the moon and back in what's called a 'moonbounce' and is a popular feat of skill for radio amateurs.

https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication

There are a multitude of videos online of people pulling off a moonbounce.

From above video >> "Looking at the signal at 10:28. I used the 2 second transmit time as a time-length reference. From the beginning of the transmission to the beginning of the echo, I measure 2.5 seconds, which is round trip time. So, 1.25 seconds one way. 1.25 seconds times 186,000 miles per second (radio wave speed) = 232,500 miles. Google shows 238,900 miles, average distance. Not bad using ruler measuring the signal on the computer screen."

The FE Wiki claims the moon is only 3000 miles above the surface of the Earth. If this were true, the propagation time for a radio wave to travel to the Moon and back would be 32.2 milliseconds.

It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon.

I look forward to the wild theories and postulations to explain why radio waves take 78x longer to travel to the moon and back in the Flat Earth model.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #1 on: February 01, 2022, 05:07:07 PM »
Quote from: scomato
It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon.

No, you cannot determine this for yourself. The process involves sending your device information over the internet to get a response from a large facility.

See this video of a Moonbounce:

He is communicating with a third party installation, and says "he heard me" and at 4:54 that "you need a pretty big station at the other end".

The Moonbounce is not conducted by setting up your own antenna, broadcasting a signal, and then receiving it. The process involves sending your data over the internet to a large (likely government funded) radio astronomy facility and then receiving back the results.

This "evidence" essentially involves asking the government how far away the Moon is. For what reason this service was made open to the public is unknown. But we may as well just go to the NASA website if we are relying on the government for our information.

From an article on the Moonbounce:

Quote
Moonbounce basics

The basis of operation of Moonbounce or EME, Earth-Moon-Earth is the use of the Moon as a passive reflector. In view of the very large distances involved and the fact that the Moon's surface is a poor reflector the path losses are colossal, but nevertheless it is still a form of communication that is theoretically possible to use, and one that many radio amateurs regularly use.

There are clearly two stations in this diagram, not one. References can be found that the technique was developed by the U.S. Military after WWII.

From another Moonbounce reference of someone in Antarctica making a Moonbounce:

https://search.informit.org/doi/pdf/10.3316/informit.535111485198853

Quote
Amateur radio operator Craig Hayhow has used the moon to bounce
a radio signal 742 000 km, from Mawson station in Antarctica to
Cornwall in England.

The Cornwall facility mentioned here is likely the Goonhilly Earth Station and 32-Meter Dish used for Moonbounces operated by the ESA:

http://www.arrl.org/news/goonhilly-32-meter-dish-to-be-active-on-moonbounce-on-september-1-2

Quote
Goonhilly 32-Meter Dish to be Active on Moonbounce on September 1 – 2

A team of moonbounce enthusiasts expect to activate the 32-meter antenna GHY-6 at Goonhilly, on the Lizard Peninsular in Cornwall (IO70jb) in the UK on September 1 – 2, operating as GB6GHY. The group, including G8GTZ, G8GKQ, and G4NNS, will be on the HB9Q logger while operational, which should be between 0800 and 1200 UTC, but “earlier if possible,” they’ve said.

GB6GHY will concentrate on 3.4 GHz on September 1 and 5.7 GHz on September 2, with the ability to switch bands immediately.

Anyone with a relatively small dish (3-meter or less) should be able to work us,” their announcement said. The European Space Agency is undertaking a project to upgrade Goonhilly Earth Station to track missions to the Moon and Mars. The work will see the GHY-6 antenna — which carried the 1985 Live Aid concert around the world — upgraded over the span of 2 years.”

This cunning proof is a service that a space agency provides.

The assertion that this is a proof that amateur operators can perform for themselves is incorrect.
« Last Edit: February 01, 2022, 06:44:42 PM by Tom Bishop »

#### SteelyBob

• 775
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #2 on: February 01, 2022, 05:31:16 PM »

The Moonbounce is not conducted by setting up your own antenna, broadcasting a signal, and then receiving it. The process involves sending your data over the internet to a large (likely government funded) radio astronomy facility and then receiving back the results. References can be found that the technique was developed by the U.S. Military after WWII.

This "evidence" essentially involves asking the government how far away the Moon is. For what reason this service was made open to the public, is unknown. But we may as well just go to the NASA website if we are relying on the government for our information.

You appear to have confused radio enthusiasts using moonbounce to communicate over long ranges with the rather simpler task of measuring the distance to the moon using radio. See this guide:

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #3 on: February 01, 2022, 05:40:02 PM »
You posted an article summarizing the concepts, written for teaching ages 11+. It's not an example of someone actually doing it themselves two ways with a small device. From the examples given previously, they are performing the Moonbounce with large dishes at a third party facility.

The article you posted even instructs the teacher to work with a large astronomy radio telescope "if they can't hear the reflected signal":

Quote
To determine whether the signal will be strong enough, the radio amateur should check the equipment sensitivity and find out exactly where the Moon is positioned in the sky prior to the activity. If they can’t hear the reflected signal, or if the visual signal is lost amongst background noise on the oscilloscope, they can use a large astronomy radio telescope at the Dwingeloo Radio Observatory in the Netherlands as the receiver (figure 7).

Again, there is no evidence that small devices can actually do this. You posted an article with lots of "ifs".
« Last Edit: February 01, 2022, 07:15:02 PM by Tom Bishop »

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #4 on: February 01, 2022, 06:13:04 PM »
Quote from: scomato
It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon.

No, you cannot determine this for yourself. The process involves sending your device information over the internet to get a response from a large facility.

Hams have been moonbouncing well prior to the advent of the internet. Even pre-Apollo.

"However radio amateurs took up EME communication as a hobby; the first amateur radio moonbounce communication took place in 1953, and amateurs worldwide still use the technique."
https://en.wikipedia.org/wiki/Earth%E2%80%93Moon%E2%80%93Earth_communication

The assertion that this is a proof that amateur operators can perform for themselves is incorrect.

Pretty small dish. They got one response after trying for an hour+.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #5 on: February 01, 2022, 06:21:40 PM »
Unsurprisingly, it is apparent that you don't bother to look at the things you post at all.

From the last video you posted:

@ 8:26 - "we are still about 20 minutes away from the scheduled start time"

@ 9:54 - "at the moment we're not hearing him"

@ 10:00 - "We are still trying to make contact. He's hearing us okay, but we're not hearing him"

It's not sending and receiving from the same device.
« Last Edit: February 01, 2022, 06:30:17 PM by Tom Bishop »

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #6 on: February 01, 2022, 06:35:06 PM »
Unsurprisingly, it is apparent that you don't bother to look at the things you post at all.

From the last video you posted:

8:26: "we are still about 20 minutes away from the scheduled start time"

9:54: "at the moment we're not hearing him"

10:00: "We are still trying to make contact. He's hearing us okay, but we're not hearing him"

It's not sending and receiving from the same device.

They got it to go one way via a moonbounce using just their equipment and the small dish. As you referenced from the video, "He's hearing us okay, but we're not hearing him." It shows you can do a mounbounce communication, at least in one direction. Hence a HAM moonbounce.

#### astroman

• 13
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #7 on: February 01, 2022, 08:12:44 PM »
I have a friend who lives literally half a mile from me and who is a fellow amateur astronomer, physicist, radio comms engineer and licenced amateur radio operator.  So I don't need to rely on YouTube videos for evidence. I can try this for myself.

We got together a while back (after I had mentioned about researching what flat Earthers believe and their claim that the Moon is only 3000 miles away... to which he replied simply ... ah bless) and he showed me how easily he could send a radio signal towards the Moon and then receive the reflected signal.  It took about 2.6 seconds for the reflected signal to show up on his oscilloscope. If we say the mean distance of the Moon is 384,400km and the speed of light (= speed of a radio wave) is 299,792.5 km/s that gives an expected time (total dist/speed) of 2.56 seconds. So our reflected signal was just about bang on time.

We then tilted the transmitter away from the Moon by a few degrees and sent out another signal.  This time no received return signal.  So obviously the first signal had hit something and been reflected back while the second signal hit nothing and simply continued out into space. Strange... I thought it might have reflected off the 'dome'.

Having the equipment and actually being able to do these experiments for ones self is so much better than relying on YouTube sometimes.
« Last Edit: February 01, 2022, 08:17:56 PM by astroman »

#### scomato

• 175
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #8 on: February 01, 2022, 10:06:56 PM »
Quote from: scomato
It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon.

No, you cannot determine this for yourself. The process involves sending your device information over the internet to get a response from a large facility.

See this video of a Moonbounce:

He is communicating with a third party installation, and says "he heard me" and at 4:54 that "you need a pretty big station at the other end".

The Moonbounce is not conducted by setting up your own antenna, broadcasting a signal, and then receiving it. The process involves sending your data over the internet to a large (likely government funded) radio astronomy facility and then receiving back the results.

This "evidence" essentially involves asking the government how far away the Moon is. For what reason this service was made open to the public is unknown. But we may as well just go to the NASA website if we are relying on the government for our information.

From an article on the Moonbounce:

Quote
Moonbounce basics

The basis of operation of Moonbounce or EME, Earth-Moon-Earth is the use of the Moon as a passive reflector. In view of the very large distances involved and the fact that the Moon's surface is a poor reflector the path losses are colossal, but nevertheless it is still a form of communication that is theoretically possible to use, and one that many radio amateurs regularly use.

There are clearly two stations in this diagram, not one. References can be found that the technique was developed by the U.S. Military after WWII.

From another Moonbounce reference of someone in Antarctica making a Moonbounce:

https://search.informit.org/doi/pdf/10.3316/informit.535111485198853

Quote
Amateur radio operator Craig Hayhow has used the moon to bounce
a radio signal 742 000 km, from Mawson station in Antarctica to
Cornwall in England.

The Cornwall facility mentioned here is likely the Goonhilly Earth Station and 32-Meter Dish used for Moonbounces operated by the ESA:

http://www.arrl.org/news/goonhilly-32-meter-dish-to-be-active-on-moonbounce-on-september-1-2

Quote
Goonhilly 32-Meter Dish to be Active on Moonbounce on September 1 – 2

A team of moonbounce enthusiasts expect to activate the 32-meter antenna GHY-6 at Goonhilly, on the Lizard Peninsular in Cornwall (IO70jb) in the UK on September 1 – 2, operating as GB6GHY. The group, including G8GTZ, G8GKQ, and G4NNS, will be on the HB9Q logger while operational, which should be between 0800 and 1200 UTC, but “earlier if possible,” they’ve said.

GB6GHY will concentrate on 3.4 GHz on September 1 and 5.7 GHz on September 2, with the ability to switch bands immediately.

Anyone with a relatively small dish (3-meter or less) should be able to work us,” their announcement said. The European Space Agency is undertaking a project to upgrade Goonhilly Earth Station to track missions to the Moon and Mars. The work will see the GHY-6 antenna — which carried the 1985 Live Aid concert around the world — upgraded over the span of 2 years.”

This cunning proof is a service that a space agency provides.

The assertion that this is a proof that amateur operators can perform for themselves is incorrect.

Do you mean to say that the Government is spoofing the true nature of the moon by artificially adding ~2.5 seconds to the receiving time?

That seems incredulous since EME propagation predates the internet by a veeery long time.

See this German article (translation provided) describing an early moonbounce experience from 1943. http://pa3fwm.nl/technotes/annex/cqdl-7-79-eme.html

"After activating the Würzmann, I made the following observation: the "perturbation" again appeared, had a duration of several impulses, and larger impulse strength than the strongest nearby targets. It didn't appear until about two seconds after switching on the transmitter and disappeared (pulsatingly) correspondingly later after switching it off. But the rest of the echo image appeared and disappeared at the instance of switching the transmitter on/off. The "perturbation" only occurred when the antenna was aimed to the east, and it disappeared immediately upon a major change of direction, but reappeared only about two seconds after rotating back to the original direction. Apparently we had detected the rising moon behind the clouds with the equipment."

The internet would not be invented for another 40 years, yet the 2-second propagation time is observed. Therefore the hoax-via-internet theory doesn't float.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #9 on: February 02, 2022, 05:35:27 AM »
Oh, so now the argument isn't that thousands of amateurs do this with a plethora of easily accessible youtube videos for documentation. The argument has suddenly significantly downgraded to having to rely on a three-day-old internet account's understanding from his experience observing it and a sparse-on-details reference from a Telefunken publicity stunt to sell the government radio and radar equipment in 1943.

« Last Edit: February 02, 2022, 02:48:00 PM by Tom Bishop »

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #10 on: February 02, 2022, 05:43:08 AM »
This is a pretty tight portable set up for moon bounces:

Here’s another guy with his backyard DIY HAM setup making a successful eme moon bounce call and response:

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #11 on: February 02, 2022, 07:07:13 AM »
I already posted that first video you posted in the second post of this thread. Nice comprehension there. Not only do you not look at the material you post, you fail to look at the material of the opponents you are responding to. Embarrassing. The person in that video is communicating with a third party installation, and says "he heard me", and at 4:54 says "you need a pretty big station at the other end". It's not an example of someone performing the moonbounce two ways with a single amateur dish.

The second video is also about communication with a third party facility. He speaks about communicating with Japan receivers at 2:46 and talks about "sending a signal to him" etc. You just keep digging yourself into a deeper hole, showing that these are not actually two-way moonbounces, and that this requires external support from third party facilities.

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #12 on: February 02, 2022, 07:24:45 AM »
You just keep digging yourself into a deeper hole, showing that these are not actually two-way moonbounces, and that this requires external support from third party facilities.

What’s the significance of “two-way”? They got it to go one way via a moonbounce using just their equipment and the small dish. As you referenced from the video, "He's hearing us okay, but we're not hearing him."
It shows you can do a mounbounce communication, at least in one direction. Hence a HAM moonbounce.

I mean they moon bounced a signal to the other guy and that guy heard it. As you pointed out, he says it in the video. Talk about digging holes…You’re not even comprehending what you yourself wrote.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #13 on: February 02, 2022, 03:56:18 PM »
Quote from: stack
What’s the significance of “two-way”?

The suggestion in the OP was that you could independently determine the distance to the Moon for yourself, and that many amateurs independently verify the Moon's distance on a regular basis. It was claimed that "It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon." This is incorrect.

#### scomato

• 175
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #14 on: February 02, 2022, 05:11:48 PM »
Quote from: stack
What’s the significance of “two-way”?

The suggestion in the OP was that you could independently determine the distance to the Moon for yourself, and that many amateurs independently verify the Moon's distance on a regular basis. It was claimed that "It is a quite elegant and simple experiment for any Flat Earthers who wish to deduce for themselves the true distance of the Moon." This is incorrect.

That is incorrect, one person absolutely can moonbounce to themselves. Here's an article from the Radio Society of Great Britain: https://rsgb.org/main/technical/space-satellites/moonbounce/

"One of the unique characteristics of EME is that it is possible to hear and observe your own transmissions echoed back approximately 2.5 seconds later as the transmitted signal propagates from the earth to the moon, is reflected, and propagates back to the earth."

There is no reason one person could not transmit and receive back to themselves. Anywhere the moon is visible, you can receive a moonbounce, it's no different if you're 50 feet from the source or 50 miles.

The reason few people do this is because setting up a 3-meter radio dish is 1) expensive and 2) wildly space prohibitive, what are you doing to do with your \$10,000 dollar 4-meter dish when you're not using it? It's much better to just listen to EME receivers that other people have sunk their lives into, like this one: http://websdr.camras.nl:8901/ and the hundred others like it: http://www.bobatkins.com/radio/ka1gt_eme_map.html The dishes are better, the recording instruments are better, it's free, there's just little reason to be your own receiver. Unless you believe that the internet is being rigged by unseen powers in an effort to invisibly deceive you, that is. There's not really a rational point to make in response to that.

But there's nothing stopping someone from doing it themselves.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #15 on: February 02, 2022, 05:18:35 PM »
That is incorrect, one person absolutely can moonbounce to themselves. Here's an article from the Radio Society of Great Britain: https://rsgb.org/main/technical/space-satellites/moonbounce/

"One of the unique characteristics of EME is that it is possible to hear and observe your own transmissions echoed back approximately 2.5 seconds later as the transmitted signal propagates from the earth to the moon, is reflected, and propagates back to the earth."

There is no reason one person could not transmit and receive back to themselves. Anywhere the moon is visible, you can receive a moonbounce, it's no different if you're 50 feet from the source or 50 miles.

You posted an article of someone who thinks it's possible, and who makes no attempt at demonstration. A very low level of evidence. That you can find anonymous authors who make such ignorant claims means nothing.

#### scomato

• 175
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #16 on: February 02, 2022, 05:31:20 PM »
That is incorrect, one person absolutely can moonbounce to themselves. Here's an article from the Radio Society of Great Britain: https://rsgb.org/main/technical/space-satellites/moonbounce/

"One of the unique characteristics of EME is that it is possible to hear and observe your own transmissions echoed back approximately 2.5 seconds later as the transmitted signal propagates from the earth to the moon, is reflected, and propagates back to the earth."

There is no reason one person could not transmit and receive back to themselves. Anywhere the moon is visible, you can receive a moonbounce, it's no different if you're 50 feet from the source or 50 miles.

You posted an article of someone who thinks it's possible, and who makes no attempt at demonstration. A very low level of evidence. That you can find anonymous authors who make such ignorant claims means nothing.

I'll find all the sources you want. How about this, then: https://www.qrz.com/db/AD6GD WA6PY as he was known in the radio community, has a well-documented account with many photos, and magazine appearances, one calling him the Master of Moonbounce.

But answer me this - if a transmitter and receiver can pull off an EME, why can't that be one person? I fail to see the logic there. Any place with a sight-line to the Moon, can receive an EME transmission, it's not like you have to know where your receiver is. Radio is a wave, not a laser pointer that must be precisely beamed back and forth.

The reason nobody does this is because communicating with people over long distances is the point of an EME, not to measure the distance of the move, although it can be used in that way.

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #17 on: February 07, 2022, 09:46:59 PM »
Here’s a 2017 world record HAM EME moon bounce between Western Australia & Delaware USA. Around the 6:00 mark, 18,950 KM:

New 10-GHz Earth-Moon-Earth World Record Set

09/15/2017
A new 10-GHz Earth-Moon-Earth (EME or moon bounce) world record has been set. On September 9, Rex Moncur, VK7MO, and Jim Malone, WA3LBI, completed a 18,949.4-kilometer contact using QRA64D. This extends by approximately 600 kilometers the previous world record of 18,337 kilometers held by DL7FJ and ZL1GSG, who used CW.

The participants said the key was to find locations with nearly 0° take-off, which essentially means across water. VK7MO operated from OF76nk at Meelup in Western Australia; WA3LBI operated from FM28io in Delaware. Both stations operated portable.

#### Tom Bishop

• Zetetic Council Member
• 10244
• Flat Earth Believer
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #18 on: February 07, 2022, 09:55:32 PM »
None of the examples of the last two posts even mentions the propagation time.

#### stack

• 3444
##### Re: Moonbounce propagation time and the distance of the Moon from Earth
« Reply #19 on: February 07, 2022, 10:56:22 PM »
None of the examples of the last two posts even mentions the propagation time.

Sure it does, at 6:22:

The column DT refers to:

The DT column in WSJT-X shows the time difference in seconds between your computer clock and each decoded station. It is common to see large deltas, sometimes exceeding a second or more.

Not to mention that they bounced off the Moon back and forth across almost 19,000 KM.