Accession Number : AD0677922

Title :   DOPPLER TRACKING OF NEAR-SYNCHRONOUS SATELLITES.

Descriptive Note : Technical memo.,

Corporate Author : JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB

Personal Author(s) : Holland,Bruce B.

Report Date : AUG 1968

Pagination or Media Count : 40

Abstract : The DODGE satellite was successfully tracked by use of single-frequency doppler data only. Prior to this experiment it was not an established fact that a near-synchronous satellite could be tracked with a doppler signal as the only source of data. Since the doppler signal was expected to be tenuous at best, the probable error sources, namely, ionospheric refraction, satellite oscillator drift, and station differential oscillator drift, were investigated and their effects noted. The orbit tracking and prediction accuracies were compared with independent measurements: the current tracking accuracy, although poor by near-earth satellite standards, is sufficient to enable most users to measure existing errors in satellite position, and the comparison of predicted satellite direction against maximum-signal-strength direction shows a standard deviation of about 1 degree. (Author)

Descriptors :   (*SYNCHRONOUS SATELLITES, *RADAR TRACKING), DOPPLER RADAR, ELECTRON DENSITY, IONOSPHERE, REFRACTION, ERRORS, RADAR SIGNALS, DRIFT, ACCURACY, SOURCES

Subject Categories : Active & Passive Radar Detection & Equipment
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE