Application of an Artificial Satellite to the Measurement of the General Relativistic "Red Shift"

In view of the paucity of experimental tests for the general theory of relativity, it is desirable to consider the uses to which a satellite vehicle could be put. The advance of the perigee is calculated similarly to the perihelion advance of mercury; it amounts to only 15 seconds of arc per year. However, the effect on a satellite clock is large and could be measured. With respect to an earth clock it is calculated to be a "red shift" for low-altitude orbits, zero shift for an orbit at one-half the earth's radius, and a "violet shift" for higher altitudes, where it approaches 710^-10. Some experimental schemes for the measurement of the clock shift are discussed; a counting technique seems to be best suited since it is capable of higher ultimate accuracy and avoids signaling problems during intercomparison arising from the motion of the satellite.