Accession Number : AD0719738

Title :   Analysis of VHF and X-Band Telemetry Systems Degradation by Reentry Environment.

Descriptive Note : Research rept. May 69-Jun 70,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Golden,Kurt E. ; McPherson,Donald A. ; Horn,Kenneth P.

Report Date : 01 FEB 1971

Pagination or Media Count : 39

Abstract : The degradation of VHF and X-band telemetry by the reentry plasma sheath has been analyzed for recent flight tests of a hypersonic reentry vehicle. A self-consistent technique utilizing the received signal strengths of both the VHF and X-band transmitters was used. It was determined that the attenuation was caused by electrons flowing back over the antennas from the stagnation region at the nose. For the X-band signal, the attenuation was a result of pattern distortion caused by refraction in the plasma layer and distortion of the field distribution in the antenna aperture. At VHF, the plasma layer is electrically thin, and the signal loss resulted from the combined effects of reflection and absorption. (Author)

Descriptors :   (*BLACKOUT(PROPAGATION), TELEMETER SYSTEMS), (*TELEMETER SYSTEMS, *PLASMA SHEATHS), (*REENTRY VEHICLES, TELEMETER SYSTEMS), ATMOSPHERE ENTRY, ATTENUATION, HYPERSONIC TEST VEHICLES, X BAND, VERY HIGH FREQUENCY

Subject Categories : Telemetry

Distribution Statement : APPROVED FOR PUBLIC RELEASE