Program

Abstract:

The primary mission of the CYGNSS constellation uses Global Navigation Satellite System Reflectometry (GNSS-R) to measure wind speed. This mission provides a unique opportunity to extract ocean surface topography from these reflected signals by comparing the delay difference between the direct and reflected signal. There are many challenges to GNSS-R altimetry such as reflected signal retracking, estimation of the ionospheric and tropospheric delays along the reflected path, calibration of instrument and timing delays between direct and reflected paths, and knowledge of the receiving satellite orbit. The primary focus of this work is to improve the CYGNSS orbit solutions by processing L1 code pseudorange and phase using JPL’s GipsyX software. Improved orbit solutions have recently been generated based solely on pseudorange data. We are looking to further improve these solutions by implementing ionospheric corrections and incorporating phase data, if we can resolve the inconsistency between the reported pseudorange and phase data.