VLBI Type Experimental Observation of GPS

Autor: Younghee Kwak, Tetsuro Kondo, Jun Amagai, Tadahiro Gotoh, Tetsuo Sasao, Jungho Cho, Tuhwan Kim
Jazyk: angličtina
Rok vydání: 2010
Předmět:
Zdroj: Journal of Astronomy and Space Sciences, Vol 27, Iss 2, Pp 173-180 (2010)
Druh dokumentu: article
ISSN: 2093-5587
2093-1409
DOI: 10.5140/JASS.2010.27.2.173
Popis: As a preparatory study for Global Positioning System-Very Long Baseline Interferometry (GPS-VLBI) hybrid system, we examined if VLBI type observation of the GPS signal is realizable through a test experiment. The test experiment was performed between Kashima and Koganei, Japan, with 110 km baseline. The GPS L1 and L2 signals were received by commercial GPS antennas, down-converted to video-band signals by specially developed GPS down converters, and then sampled by VLBI samplers. The sampled GPS data were recorded as ordinary VLBI data by VLBI recorders. The sampling frequency was 64 MHz and the observation time was 1 minute. The recorded data were correlated by a VLBI correlator. From correlation results, we simultaneously obtained correlation fringes from all 8 satellites above a cut-off elevation which was set to 15 degree. 87.5% of L1 fringes and 12.5% of L2 fringes acquired the Signal to Noise Ratios which are sufficient to achieve the group delay precision of 0.1nsec that is typical in current geodetic VLBI. This result shows that VLBI type observation of GPS satellites will be readily realized in future GPS-VLBI hybrid system.
Databáze: Directory of Open Access Journals