The Theory of Relativity will begin to fall apart in 2016/2017

[dasmiller]

Once again GR, being the general application of special relativity, explicitly includes, well, SR. Seriously?!?! "missing SR signal" "wrong GR signal" ?!?! Apparently the message about GR entirely and specifically including SR just ain't getting through.

Is anything?

 

[The Man]

Is anything?

Apparently not. Perhaps we just need a member who is a grandmother to tell him?

 

[Bjarne]

So now multiple triangulation points of reference don't work?

Why not Bjarne?

If I have multiple angles of reference, lets say just a hundred for example, why can't I know the orbital position of a GPS satellite?

All would point to a certain orbit,- but based on the prevailing interpretation of GR and SR, and therefore not the true orbit..

 

[dasmiller]

All would point to a certain orbit,- but based on the prevailing interpretation of GR and SR, and therefore not the true orbit..

But using those range measurements, we predict the spacecraft's future position with extremely high accuracy. How is this possible if we're getting the orbit wrong?

 

[Bjarne]

First, if the real problem is that the altitude measurement is wrong, why won't that affect the ISS experiment as well? Unless it's got an accurate way to measure the altitude that doesn't rely on propagating a signal between Earth and the satellite?*

Maybe you are right, maybe the TDOA also will measure the ISS altitude. I haven't found further information about how altitude will be measured on ISS.

Second, if the GPS altitude measurements were not accurate, then the GPS orbit propagation would not be accurate and, as stated repeatedly, GPS orbit propagation is very accurate.

I don't agree
When a satellit is inserted in orbit you can easy measure the time dilation on board, you can also easy set up software to syncronize the dilation.
So fare you don't need to know very much more, - also not the math behind relativity, but only how to program a computer software, able to eliminate the time dilation orbit by orbit, and the GPS system is working fine..

You can also easy explain the cause of the dilation by combining SR and GR contributions, but this is not very important..

Therefore if there is a period with missing SR signal each orbit (which you are not aware of) , (when moving north) you can easy replace the missing SR signal with a estimated GR signal, which make you believe the orbit is different than it really is.

Maybe the modified theory of relativity can be confirmed, only by critical researching satellites time dilation synchronizing’s data.. I mean who will dig a hole if there is no reason? And who will be critical to GPS time dilation synchronizing’s, so long nobody will expect any reason to be suspicious that something might be wrong with SR

*Offhand, I know of 2 ways to do this, but neither is applicable to the ISS experiment.

Let me hear about it..

 

[Bjarne]

But using those range measurements, we predict the spacecraft's future position with extremely high accuracy. How is this possible if we're getting the orbit wrong?

You mean radar measurement
If so you will measure the speed, not the altitude

 

[dasmiller]

I don't agree
When a satellit is inserted in orbit you can easy measure the time dilation on board, you can also easy set up software to syncronize the dilation.
So fare you don't need to know very much more, - also not the math behind relativity, but only how to program a computer software, able to eliminate the time dilation orbit by orbit, and the GPS system is working fine..

You can also easy explain the cause of the dilation by combining SR and GR contributions, but this is not very important..

Therefore if there is a period with missing SR signal each orbit (which you are not aware of) , (when moving north) you can easy replace the missing SR signal with a estimated GR signal, which make you believe the orbit is different than it really is.

But it's not just a matter of getting the GPS clocks right. For GPS to work, we have to know, in advance, exactly where the spacecraft will be. That means we have to know the orbit itself very, very accurately.

 

[dasmiller]

You mean radar measurement
If so you will measure the speed, not the altitude

No, I don't. I don't know of anyone ever doing a radar measurement of a GPS satellite, though there are a lot of radars out there so it's probably happened.

 

[The Man]

You mean radar measurement
If so you will measure the speed, not the altitude

Uhm, radar as a speed detection and enforcement device is neither its only application nor how it was developed.

https://en.wikipedia.org/wiki/Radar

Radar was secretly developed by several nations in the period before and during World War II. The term RADAR was coined in 1940 by the United States Navy as an acronym for RAdio Detection And Ranging.[1][2] The term radar has since entered English and other languages as a common noun, losing all capitalization.

You will note the "Ranging" part.

 

[Dancing David]

All would point to a certain orbit,- but based on the prevailing interpretation of GR and SR, and therefore not the true orbit..

The effects of GR and/or SR while measurable on the GPS signal are very small compared to the actual position of velocity of the satellite

 

[Daylightstar]

... you can also easy set up software to syncronize the dilation. ...

Sure Bjarne, a monkey can do it .....

 

[Bjarne]

But it's not just a matter of getting the GPS clocks right. For GPS to work, we have to know, in advance, exactly where the spacecraft will be. That means we have to know the orbit itself very, very accurately.

Right, because we need to know the distance to other GPS satellites. So fare so god.

But it’s still not important for the GPS to work, that we compare theoretical orbit eccentricity, with these data that is measured.

This is only done if we are suspicious to whether theory and measurement agree and therefore a scientific test task.

 

[dasmiller]

Right, because we need to know the distance to other GPS satellites. So fare so god.

But it’s still not important for the GPS to work, that we compare theoretical orbit eccentricity, with these data that is measured.

It is absolutely essential to GPS' operation that we know all of the orbit elements very, very accurately. Otherwise, we can't forecast where the spacecraft will be and the system would be useless.

Again, you seem to have some serious misunderstandings about how GPS works.

This is only done if we are suspicious to whether theory and measurement agree and therefore a scientific test task.

This is not correct.

 

[Bjarne]

No, I don't. I don't know of anyone ever doing a radar measurement of a GPS satellite, though there are a lot of radars out there so it's probably happened.

I wrote that altitude could maybe not be measured by radar, - But I am not sure, properly that too can be done very accurate. - So we properly have all what we need to reveal any theoretical / measureable disagreement.

 

[Bjarne]

It is absolutely essential to GPS' operation that we know all of the orbit elements very, very accurately. Otherwise, we can't forecast where the spacecraft will be and the system would be useless.
.

If the TDOA data is used to calculate the distance between satellites (or orbit altitude) it will not be so bad, I believe - but so soon such data is compared with theoretical calculated data (for polar satellites) trouble begins..

 

[dasmiller]

If the TDOA data is used to calculate the distance between satellites (or orbit altitude) it will not be so bad, I believe - but so soon such data is compared with theoretical calculated data (for polar satellites) trouble begins..

It's compared continuously, around the world, all the time! Sheesh

 

[dasmiller]

I wrote that altitude could maybe not be measured by radar, - But I am not sure, properly that too can be done very accurate. - So we properly have all what we need to reveal any theoretical / measureable disagreement.

GPS ranging is not normally done with radar. As far as I know, radar has never been used to update the actual GPS nav message

 

[Bjarne]

It's compared continuously, around the world, all the time! Sheesh

I do not agree.
It required that satellites are dedicated for such scientific test, like for example Galileo 5 & 6, or ISS

GPS has mainly a commercial purpose
if clock all the time is synchronized you will not be able to have long lasting test

 

[dasmiller]

I do not agree.

It's not a matter of opinion

It required that satellites are dedicated for such scientific test, like for example Galileo 5 & 6, or ISS

Why? What's different about those satellites? How are the dark-flow effects big enough to be measured by Galileo and ISS, but too small to be measured by GPS?

GPS has mainly a commercial purpose

For heaven's sake, GPS is procured and managed by the USAF, and they are not a commercial entity.

if clock all the time is synchronized you will not be able to have long lasting test

I have no idea what this means.

 

[MRC_Hans]

But it’s still not important for the GPS to work, that we compare theoretical orbit eccentricity, with these data that is measured.

Yes, it is important. Apparently, you have no idea how GPS works, but simply said your receiver times the distance to several satellites and calculates the position from that. Obviously, if the exact position, including altitude, of the satellites, then your GPS device will not be able to get the correct position.

Hans