Simulations and Analysis of BeiDou Navigation Satellite System (BDS)-Relectometry Delay-Doppler Maps for Vegetation

摘要

Global Positioning System-Reflectometry (GPS-R) is a new promising technique, which uses the reflected signals of the GPS constellation to remotely sense the geophysical parameters of the ocean and land surface. Some initial results were obtained from GPS-R in ocean surface characteristics and soil moisture, while, vegetation sensing is paid attention recently. With the development of Chinese independent Beidou Satellite Navigation System (BDS), it will play a key role in positioning, navigation and timing as well as potential applications of BDS-Reflectometry (BDS-R), e.g. vegetation monitoring using the Delay-Doppler Map (DDM) of BDS-R. Therefore, it is extremely necessary to simulate the vegetation BDS-R DDM maps. Z-V model is a commonly used GPS-R scattering model and its applications include the sea wind, oil slick and soil moisture. In this paper, it is the first time for vegetation DDM simulations from BDS-R, while the vegetation scattering properties are simulated using the modified Bi-mimics model, which can be used to calculate any transmit and receive polarization combinations, assuming that the received power is coming from the first Fresnel zone. The theoretical simulations of DDM are helpful for the further BDS-R vegetation parameters retrieval, and some discussions and analysis are further given.