G05 GNSS++: Emerging Technologies and Applications

IAG (Geodesy)



25-Jun-2015, 08:30 - 10:00


 
Abstract content:

Radio occultation excess phases to derive bending angle and refractivity over Poland

Since 2015 Wroclaw University of Environmental and Life Sciences (WUELS) routinely collects and processes GPS Radio Occultation (GPS RO) level1b data of FORMOSAT-3/COSMIC mission using products provided by COSMIC Data Analysis and Archival Center (CDAAC). From over 1,500 daily occultations available worldwide, we find these occurred over the area of Poland to derive atmospheric profiles of bending angle and refractivity. In this study, we present results for processing of satellite signal excess phases on both, L1 and L2 frequencies obtained from atmPhs real time product. As the phase-locked loop (PLL) method cannot provide precise retrievals in the troposphere, open-loop (OL) tracking is applied to enhance results of calculated bending angles. Conversion to refractivity can be then carried out by Abel inversion. Reference values of calculated parameters are obtained from atmPrf product provided by CDAAC as both, bending angle and refractivity are unusual in meteorological observing system, thus making the quality assessment of radio occultation retrievals difficult when using in-situ measures. However, refractivity is additionally evaluated using radiosonde reports by comparing radio occultation profiles in the immediate vicinity of three Polish stations.

 
Author(s):
P. Hordyniec1, W. Rohm1, C.Y. Huang2, W.H. Yeh2.
1Wroclaw University of Environmental and Life Sciences, Institute of Geodesy and Geoinformatics, Wroclaw, Poland.
2National Central University, GPS Science and Application Research Center, Taoyuan, Taiwan Republic of China.

 

Keywords:
bending angle     COSMIC     GPS RO     radio occultation     refractivity