Improved Water Level Retrieval from Epoch-by-Epoch Single and Double Difference GNSS-R Algorithms

• Main Authors: WANG Nazi, BAO Lifeng, GAO Fan
• Format: Article
• Language: zho
• Published: Surveying and Mapping Press 2016-07-01
• Series: Acta Geodaetica et Cartographica Sinica
• Subjects: global navigation satellite system reflectometry (GNSS-R); reflected signals; single difference; double difference; water level height
• Online Access: http://html.rhhz.net/CHXB/html/2016-7-795.htm

GNSS-R is a new technology for monitoring the water level with high efficiency. Compared with conventional water level measurement technique, such as satellite altimetry and tide gauges, GNSS-R can observe more reflected points with high temporal and spatial resolution and unaffected by the influence of the plate vertical motion. This paper presented an improved cGNSS-R altimetry algorithm based on single difference to derive the reflector heights epoch-by-epoch, which can enhance the temporal and spatial resolution of surface height measurements, furthermore, the other algorithm based on the double differenced carrier phase measurements was also presented in this paper. By using the observed data of cGNSS-R altimetry experiment conducted on Qinghe bridge of East Lake, Wuhan, the reflector heights between the reflected antenna and the lake surface were given to prove the above mentioned algorithms, and the precision were ±2~±4 cm. The results show that the proposed algorithms based on single and double difference which are used for water level retrieval can sufficiently decrease the influences due to clock error, ionospheric and tropospheric error.