ANALYSIS OF THE EFFECTS OF SRT AND GRT IN THE SATELLITE SYSTEM GPS
What the Global Positioning System Tells Us about Relativity. (Tom Van Flandern) (1998) (pdf)
The GTR predicts that atomic clocks of GPS satellite system work faster in orbit (approx. 45900 ns / day), because they are subject to a lower gravitational field, than atomic clocks on Earth’s surface.
The STR predicts that atomic clocks work slower, on the contrary (approx. losing 7200 ns / day against Earth’s clocks).
Therefore, atomic clocks on satellite are synchronized and have a compensation mechanism that accounts for the predicted effects.
We can tell for sure that the predictions of the theory of relativity are exact with a high degree of exactitude, for duration of several days.
Relativistic Effects in the Global Positioning System. (Neil Ashby) (2006) (pdf)
The Global Positioning System (GPS) provides a superb opportunity to introduce relativity concepts to undergraduate students, including non-physics majors. Familiarity with the numerous applications of GPS motivates students to understand relativity. A few fundamental principles need to be introduced, including the postulates of special relativity and the universality of free fall. Then a series of thought experiments leads to the breakdown of simultaneity, the Sagnac effect, the first-order Doppler effect, gravitational frequency shifts, and time dilation. This article presents this chain of thought and explains the essential role of special and general relativity in the GPS.
Ronald Ray Hatch ‑ an expert in the use of GPS for precision farming, as well as other applications. Currently a consultant to John Deere, he was formerly the Director of Navigation Systems Engineering and Principal and co-founder of NavCom Technology, Inc.
GPS.gov: http://www.gps.gov/governance/advisory/members/hatch/
db.naturalphilosophy.org: http://db.naturalphilosophy.org/member/?memberid=257
Those Scandalous Clocks. (Ronald R. Hatch) (2004)
Both VLBI (Very Long Baseline Interferometry) and GPS (Global Positioning System) indicate that earth-based clocks are biased as a function of their position in the direction of the earth’s orbital velocity. The evidence for these biases is discussed, and the result is confirmed by comparison of earth-based clocks with millisecond pulsars. These clock biases are precisely such as to cause the speed of light to appear as “c” in the earth’s inertial frame. This shows that the speed of light is not isotropic in the earth’s frame and that the Lorentz transformation is only an apparent transformation that results from Selleri’s inertial transformations combined with clock biases.
Relativity and GPS. (Ronald R. Hatch) (1995) (pdf)
Four problems with the general theory were presented. An alternative theory was proposed of a solid elastic ether which constituted a particular representation of the Lorentz ether theory. This new theory was shown to provide a simple resolution to the general theory problems. The particular claim of the general theory that a freely falling body is not acted upon by external forces was explored at length. It is clearly not valid. It predicts gyroscopic behavior which is clearly not realized. In addition, it should be capable of direct falsification with the launch of the new GPS satellites capable of intersatellite tracking.
Finally, several predictions have been made in the course of the development. Specifically, it is predicted:
(1) that gravitational radiation will never be detected;
(2) unambiguous evidence for a black hole will never be found; and,
(3) the amount of geodetic precession measured on the Gravity Probe B experiment will be one-third greater than that predicted by the general theory.
In Search of an Ether Drift. (Ronald R. Hatch) (2002) (pdf)
Special relativity theory (SRT) claims equivalence of all inertial frames, but it is generally acknowledged that there exists a dipole temperature distribution in the cosmic background radiation (CBR), which indicates that the solar system is moving through this unique inertial frame at a speed of approximately one percent of the speed of light.
This evidence for a unique frame conflicts with SRT, and so motivates a search for additional evidence. Presumably, any ether drift should be directly detectable via experiment in either an earth-centered frame, or a sun-centered frame, or both. Spinning Mossbauer experiments, the Global Positioning System (GPS), and Very Long Baseline Interferometry (VLBI) are here analyzed for any evidence of ether drift; i.e., for evidence that the speed of light is not isotropic in all inertial frames. Though none of the experiments provides any direct evidence for ether drift, they do provide substantial indirect evidence.
Contrary to the assertion of Special Relativity, the speed of light is not always constant relative to a moving observer. The Global Positioning System (GPS) shows that the speed of light in the Earth Centered Inertial (ECI) non-rotating frame remains at c relative to the frame?but not relative to an observer or receiver moving in that frame. When a GPS receiver changes its translation speed relative to the ECI frame, the speed of light measured relative to the receiver changes. A crucial experiment of the constancy of the speed of light relative to a moving receiver could be conducted in the following way: Let two GPS satellites and two airplanes be positioned in a straight line. Let the two airplanes travel at the same speed directly toward one of the two satellites and directly away from the other satellite. The travel time differences of GPS signals arriving at the two airplanes is measured and recorded with the airplanes flying first toward one of the satellites and then flying the opposite direction toward the other satellite. The travel time differences obtained as the airplanes fly in opposite directions are compared. If the travel time difference is the same when the velocity of the airplanes is changed, then the speed of light is indeed constant relative to the moving airplanes, otherwise it is not. The calculation using the GPS range equation and the results of a Real-Time Kinematic (RTK) differential GPS test have shown that the constancy of the speed of light relative to moving airplanes is not correct. The change of the time difference could reach about 10 ns for subsonic airplanes and 30 ns for supersonic airplanes. The result of this crucial experiment is not only important scientifically, but also indicates the possibility of a new way to directly measure vehicle speed relative to the ECI frame.
Clock Behavior and the Search for an Underlying Mechanism for Relativistic Phenomena. (Ronald R. Hatch) (2002)
The Special Relativity Theory (SRT) and the General Relativity Theory (GRT) sometimes exhibit clock effects of equal magnitude which cancel and sometimes exhibit clock effects of equal magnitude which are additive. This cannot be coincidence, yet there is nothing within the two disjoint relativity theories to suggest an underlying mechanism. The effects appear to be related to energy, but the SRT treats energy as relative and the GRT treats an orbiting body as following a force-free trajectory. Thus an alternative to the Einstein theories seems to be required. I have proposed what I call a Modified Lorentz Ether Theory (MLET) which extends the Lorentz ether concepts to cover gravitational phenomena. Following a brief review of MLET concepts, it is contrasted with SRT concepts. Current data available from a number of modern experiments are evaluated with regard to both MLET and SRT. In general, MLET provides a more coherent and consistent explanation of the data. In the last major section of the paper it is shown that in the earth-centered inertial (ECI) frame Global Positioning System (GPS) clocks are not adjusted for the differential effect of the sun’s gravitational potential. SRT has no valid explanation for this phenomenon and is thereby refuted. MLET by contrast shows that the differential effect of the sun’s gravitational potential is absorbed into the clock bias which converts the Selleri transformation into an apparent Lorentz transformation. This is very strong evidence that some form of Lorentz ether theory is valid and that the Einstein theories are invalid.
GPS, clocks and Relativity. Presentation. (Ronald R. Hatch) (2015) (pdf)
GPS and Relativity Misconceptions 1. (Blog on relativity and cosmology — Burt Jordaan) (2011)
GPS and Relativity Misconceptions 2.
GPS and Relativity Misconceptions 3.
Einstein Clocks and the Sagnac Effect (in the context of the GPS).
Ether drift resulting from the rotation of the Earth has been detected. This was accomplished using GPS technology in a modified Michelson-Morley experiment. The original Michelson-Morley experiment searched for ether drift by observing round-trip light travel time differences using interference fringe shifts. This method is limited by length contraction effects that significantly reduce any fringe shifts. In the modified approach elapsed time for one-way light transmission is directly determined using GPS clocks. The method yields travel time differences for light transmission in the East-West direction but not in the North-South direction consistent with rotationally-induced ether drift.