2026-04-13T02:01:29Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/226192026-02-04T08:06:04Zcom_2072_1033col_2072_452950

00925njm 22002777a 4500 dc Valencia Domènech, Enric author Zavorotny, Valery author Akos, Dennis M. author Camps Carmona, Adriano José author 2014-07 Reflectometry of signals of opportunity such as those emitted by a global navigation satellite system, known as GNSS-R, has been developed over the past years as a technique with great potential for ocean scatterometry, among other applications. Different approaches have been proposed to use GNSS-R for remote sensing of ocean surface roughness. One of them is based on deriving some descriptor/metric from the measured delay-Doppler map (DDM) and directly relating it to a geophysical property of the scattering surface. For instance, different descriptors have been proposed in the literature to measure the DDM spreading caused by the increase in ocean surface mean square slopes due to surface winds. In this paper, a new descriptor based on the DDM is proposed for wind direction retrieval. This descriptor, designated as the skewness angle 1,skew, measures the asymmetry in the DDM power distribution along the Doppler frequency axis, and it was modeled as a function of wind direction by means of a simulation study. Then, that model was validated using real GNSS-R data from an airborne experiment. After validation, the DDM skewness model was successfully used for wind direction retrieval, with a resulting rms error on the order of 20° Peer Reviewed Postprint (published version) Àrees temàtiques de la UPC::Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica::Teledetecció Àrees temàtiques de la UPC::Enginyeria agroalimentària::Ciències de la terra i de la vida Remote sensing Earth sciences Delay-Doppler mapping global navigation satellite system (GNSS) Global Positioning System (GPS) ocean remote sensing ocean surface wind direction Reflected GPS Teledetecció Ciències de la terra Using DDM asymmetry metrics for wind direction retrieval from GPS ocean-scattered signals in airborne experiments