Measuring Wind Speed, Sea Surface Height and Soil Moisture with Spaceborne GNSS-Reflectometry Seminar

Event details

Global Navigation Satellite System-Reflectometry or GNSS-R represents an innovation in remote sensing. It uses signals of opportunity from navigation constellations (e.g. GPS, GLONASS, Galileo) scattered by the surface of the earth, to retrieve a number of different geophysical properties. Compared to conventional satellites, GNSS-R offers the advantage of high space/time sampling, ability of L-Band navigation signal to provide measurements even under heavy rain, exploitation of existing transmitted signals (i.e. no transmitter is required onboard the satellite) and the need for very simple, low-cost, low power and lightweight receivers. These are all essential characteristics to easily build a constellation of such receivers, and it ultimately lead to the effort by NASA to develop the first GNSS-R mission called CYGNSS. CYGNSS is a constellation of 8 microsatellites, where the main scientific objective is to measure wind speed in Tropical Cyclone conditions, but which will gather GPS reflections over the whole latitudinal band of +-35°, and over both oceans and land. Over the ocean, GNSS-R provides measurements of wind speed with very good accuracy. Beside the scatterometric application, the concrete possibility to use spaceborne GPS signals reflections for sea surface height and soil moisture retrieval has also been demonstrated very recently. Here I will present an overview of the latest achievements in spaceborne GNSS-R, with a focus on wind speed, sea surface height and soil moisture, using data from the TechDemoSat-1 satellite. The work planned for the future, espcially after the launch of CYGNSS on October 2016, will be also discussed.