Computation Approach for Quantitative Dielectric Constant from Time Sequential Data Observed by CYGNSS Satellites

This paper describes a computation method for obtaining dielectric constant using Global Navigation Satellite System reflectometry (GNSS-R) products. Dielectric is crucial component in the soil moisture retrieval process reflected GNSS signals. The reflectivity circular polarized signals combined with equation that used radiometer observations. Data from Cyclone (CYGNSS) mission, an eight-nanosatellite constellation GNSS-R, are computing constant. Soil Moisture Active Passive (SMAP) mission to measure through its radiometer, and they considered as reference confirm accuracy of new calculation method. analyzed locations have been chosen correspond sites calibration validation SMAP product in-situ measurement data. retrieved results, especially case specular point around Yanco, Australia, show estimated results track closely Root Mean Square Error (RMSE) approximately 5.73. Similar can be obtained when located near Texas Network (TxSON), USA. These indicate analysis procedure well-defined, it lays foundation quantitative content results. Future work will include applying determine characteristics allow separation coherent incoherent delay Doppler maps, well develop local models.