Doppler Translocation Test Program.
Final rept. Oct 72-Sep 73,
JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB
Pagination or Media Count:
The report covers a program of test and evaluation of the ANPRN-6 XN-1 Doppler Backpack equipment for use in artillery surveying and, possibly, engineering survey work. Doppler data were obtained by the U.S. Army, U.S. Navy, and the U.S. Coast Guard simultaneously to determine the effectiveness of the various parameters in various modes of operation. The Doppler equipment uses the Navy Navigation Satellite Systems radio transmissions of the satellite ephemeris along with the Doppler-shift in carrier frequency to determine the geographical coordinates of the Doppler receiving equipment with the aid of a computer. The Backpack equipment, in particular, is designed for the translocation mode where two or more Backpacks receive simultaneously from a satellite, thereby enabling the determination of the one Backpack position with respect to the other. It was concluded from the test that significant improvement in accuracy could be achieved by incorporating time recovery error correction even without ionospheric refraction correction for distances up to 100 km. It was further concluded that an accuracy of 5 meters rms or better is possible with time recovery correction along with 3-dimensional computational software using 2 to 3 satellite passes.
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