Accession Number : ADA298107

Title :   GPS Antenna Multipath Rejection Performance,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Dinius, A. M.

PDF Url : ADA298107

Report Date : 07 AUG 1995

Pagination or Media Count : 44

Abstract : A GPS antenna multipath rejection performance evaluation was conducted. Ground reference station antennas and aviation patches were tested for their ability to reject a multipath signal. Different types of ground plane structures were used such as choke rings, ground planes, and mock sections of fuselage. Frequencies transmitted were L1 (1575 MHz), L2 (1227 MHz), and the median GLONASS frequency (1609 MHz ). Receive amplitude and phase were measured on each antenna. Subsequently, these data were converted to absolute gain for a right hand and left hand circularly polarized signal as a function of satellite elevation angle. Two types of multipath signals were considered: ground bounce multipath and building or structure bounce multipath. Ground bounce multipath typically occurs at low satellite elevation angles while structure bounce multipath can occur at any satellite elevation angle. Separate analysis methods were used to assess an antenna's ability to reject either type of multipath. This report describes the data collection methods, data reduction and analysis, and the results.

Descriptors :   *GLOBAL POSITIONING SYSTEM, *AIRCRAFT ANTENNAS, CONVERSION, POLARIZATION, PLANAR STRUCTURES, DATA REDUCTION, GAIN, FUSELAGES, DATA ACQUISITION, ELEVATION, RADIO SIGNALS, MULTIPATH TRANSMISSION, LOW ANGLES, CIRCULAR ANTENNAS, INDUCTORS.

Subject Categories : Electrical and Electronic Equipment
      Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE