SR and one-way light speed tests

Has any scientist put his/her name to a paper that clearly shows research into the <b>accuracy of GPS and the measurements of the speed of light?</b> Or is this a silly question, since the whole GPS system is built around formulas that set the speed of light to a constant value.

My analogy to the accuracy of GPS is similar to that of low quality CCTV images.
By using several low quality CCTV cameras pointing at an image, and with clever image processing you can produce a shape detailed clear image.

Similarly, processing of GPS data can give very accurate references to points on the Earth's surface, through use of electronic data only and without need to verify satellite positions optically.

PS: I believe Miller's work is of the highest standard for light beam interferometry - more so than the work of Michelson and Morley. Einstein and associates without proper review brushed his work (bad science due to political bias), knowing that the positive result would end his theories of relativity.

wisp

"particles of nothingess"

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[wisp]: Has any scientist put his/her name to a paper that clearly shows research into the <b>accuracy of GPS and the measurements of the speed of light?</b><hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Yes, I have for one. See “What the Global Positioning System tells us about relativity”, in “Open Questions in Relativistic Physics”, F. Selleri, ed., Apeiron, Montreal, pp. 81-90 (1998). Also available at [url] metaresearch.org/cosmology/gps-relativity.asp [/url].

Several papers have been published determining limits on the possible variability of the speed of GPS signals. These are in the various GPS journals, with the popular ones in GPS Magazine. I made by far the most conservative estimate, allowing for the largest possible systematic errors: +/-12 m/s. Some of the papers claim a maximum variance almost two orders of magnitude smaller.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Or is this a silly question, since the whole GPS system is built around formulas that set the speed of light to a constant value.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

It is a question that several investigators thought was worthy of research and publishing an answer. No assumption was made when GPS was planned, but the system would have been much more complicated if the speed of radio signals in the Earth-centered inertial frame had turned out to be variable.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>My analogy to the accuracy of GPS is similar to that of low quality CCTV images. By using several low quality CCTV cameras pointing at an image, and with clever image processing you can produce a shape detailed clear image.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

You are speaking of civilian receivers, which are too crude for most research purposes. With Monitor Station data, no averaging is involved. One has a new, independent measurement to every satellite in the sky from every ground station every 1.5 seconds. In Monitor Station data, what is measured is the time interval between transmission from satellite and reception on the ground, using atomic clocks at both ends and operating from well-known ground locations. Satellite orbits are also re-determined every 12 hours, but are independently checked with optical and laser ranging data. They are verified to tens of centimeters.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Similarly, processing of GPS data can give very accurate references to points on the Earth's surface, through use of electronic data only and without need to verify satellite positions optically.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

There is no need to continually verify satellite positions optically because, whenever they are checked that way, they are found to be spot on. Nonetheless, two satellites with retro-reflectors are continually monitored.

For a tutorial on GPS measurements, see [url] metaresearch.org/solar%20system/gps/absolute-gps-1meter.ASP [/url]. -|Tom|-

I see from the above GPS satelites orbit exactly as calculations indicate. Is the orbital data available at JPL/Horizons or another site? And are the calculated details available? Is a berycenter used for the Earth/moon gravity system?

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Jim]: Is the orbital data available at JPL/Horizons or another site? And are the calculated details available?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

The paper at our web site gives a sample of the data and the calculation details. The problem with our data set is that it was acquired during the time period when GPS raw data was still classified. It was declassified by Clinton in 2000. Do an internet search for places that now carry this type of data. I seem to recall that the U.S. Coast Guard carried it.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Is a barycenter used for the Earth/moon gravity system?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

What does it mean to "use" a fictitious point? The gravitational force of the Moon is fully accounted for in the GPS satellite orbits. Practical GPS work is done in the Earth-centered inertial frame of reference. -|Tom|-

The worst-case scenario for ether detection is if its flow is perpendicular to the ecliptic – Earth’s orbital plane. This is what Miller found as the result of 30 years research with over 200,000 measurements, and he suggests its velocity is 200,000 m/s. If this is correct then lights speed parallel to the ether flow will slow by (3E8 - square root[9E16-4E10] = 67 m/s) and this will produce a satellite to Earth measurement error of (67m/s * 0.08s = 5 m) in measurements parallel to the ecliptic. This may be small enough to go unnoticed by the GPS and be missed by any optical checks.

I have read the metaresearch paper on GPS several times (good paper). Also, I found a reference by Trimble about the lack of optical triangulation verification of GPS satellite positions, because the system works using a type of radio wave trilateration.

Wisp theory can challenge special relativity on every point except the prediction of a change in the speed of light due to ether flow. I am a little concerned that the GPS route has too many variables to prove a change in the speed of light occurs. So searching for any proof of simpler controlled one-way tests is a preferred option. This has shown that Miller and DeWitte have both revealed positive ether results with sidereal period variation. Even the original M-M experiment had a very small positive result, but it was ignored and has been left out of the history books.

wisp

"particles of nothingness"

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[wisp]: The worst-case scenario for ether detection is if its flow is perpendicular to the ecliptic – Earth’s orbital plane. This is what Miller found as the result of 30 years research with over 200,000 measurements, and he suggests its velocity is 200,000 m/s. If this is correct then light's speed parallel to the ether flow will slow by (3E8 - square root[9E16-4E10] = 67 m/s) and this will produce a satellite to Earth measurement error of (67m/s * 0.08s = 5 m) in measurements parallel to the ecliptic. This may be small enough to go unnoticed by the GPS and be missed by any optical checks.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Miller's measurement methods were 1000 times less accurate than GPS. Miller's errors were measured in km/s, GPS's errors in m/s.

But the key reason why the above calculation is irrelevant is that the GPS signals travel between satellites and ground stations in all directions in space, not just in the plane of the ecliptic. Every station on the Earth's surface measures GPS satellites in every direction in the sky. You could eventually find a signal path, satellite to ground, traveling from the direction of any star on the sky.

So if there were any aether wind in any direction, it would immediately cripple and disable the entire GPS system, which cannot operate at all in the face of speed changes of order km/s.

Even if all the signals did just happen to be confined to a single plane, 5 meters is way outside the signal noise. The rms errors are now under 1 meter, or under 12 m/s in signal speed (which is lightspeed).

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>I found a reference by Trimble about the lack of optical triangulation verification of GPS satellite positions, because the system works using a type of radio wave trilateration.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

GPS satellites can be tracked the same as others by optical astrometric telescopes. The only reason this is not done with more regularity is because past experience showed that the optical and radio wave methods were fully equivalent for all the satellites compared, but the optical methods led to less accurate orbits. So now, to get the best orbits, radio signal data is preferred. It is mixed with laser ranging data when that is available.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>I am a little concerned that the GPS route has too many variables to prove a change in the speed of light occurs.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

As with any high-precision technique, many small factors can affect the signals at small levels. But these can be, and are, calculated and their effects removed from the data. A good example is the correction for ionispheric delay. While often neglectable at night, delays can reach more than 10 meters by day. But GPS Monitor Station data sends the same signal at two different frequencies, which suffer different ionosphere delays. And the difference in delay can be measured and used to calculate the exact amount of the total delay at both frequencies. So this is not a "variable", but merely a consideration in any proper analysis.

But even if the ionosphere and all the other "variables" were neglected totally, Miller's results are still proved to be an effect occuring within his measurment environment, because the radio signals from all directions in space have now been shown to travel at a constant speed.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>So searching for any proof of simpler controlled one-way tests is a preferred option.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

It is difficult to conceive of a simpler experiment that would not have enormous data complications. Consider that GPS signals make 99% of their journey in a vacuum. By contrast, any ground experiment would need to be done in air. Air densities can vary greatly depending on lots of circumstances. Moreover, Miller used light and GPS uses radio waves. Most things, including air and even clouds, are much more transparent to (i.e., are less affected by) radio waves than for light.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>This has shown that Miller and DeWitte have both revealed positive ether results with sidereal period variation. Even the original M-M experiment had a very small positive result, but it was ignored and has been left out of the history books.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Michelson agreed that his results were null to within experimental errors. Only Miller did not concede this. But Miller's results, whatever they measured, did not measure changes in the speed of radio signals, which are now known to have no speed variations in any direction in space at any time of day or any season of the year to within at worst +/- 12 m/s.

Don't waste time going down dead-end paths once they are proved to be dead-end. Life is too short, and there are too many interesting problems in need of attention. -|Tom|-