Maria Paola Clarizia

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A retrieval algorithm is presented for the Level 2 ocean surface wind speed data product of the Cyclone Global Navigation Satellite System (CYGNSS) mission. The algorithm is based on the approach described by Clarizia et al., 2014. The approach is applied to the specific orbital measurement geometry, antenna, and receiver hardware characteristics of the(More)
[1] A study of the retrieval of sea surface roughness using Global Navigation Satellite System-Reflectometry (GNSSR) from satellite is presented. Delay-Doppler Maps (DDMs) from the SSTL UK-DMC satellite are analyzed to retrieve directional Mean Square Slopes (MSSs). Results are compared to theoretically-derived MSSs and in situ measurements from co-located(More)
A Minimum Variance (MV) wind speed estimator for Global Navigation Satellite System-Reflectometry (GNSS-R) is presented. The MV estimator is a composite of wind estimates obtained from five different observables derived from GNSS-R Delay-Doppler Maps (DDMs). Regression-based wind retrievals are developed for each individual observable using empirical(More)
This paper develops and characterizes the algorithms used to generate the Level 1 (L1) science data products of the Cyclone Global Navigation Satellite System (CYGNSS) mission. The L1 calibration consists of two parts: the Level 1a (L1a) calibration converts the raw Level 0 delay–Doppler maps (DDMs) of processed counts into received power in units of watts.(More)
An analysis of spaceborne Global Positioning System reflectometry (GPS-R) data from the TechDemoSat-1 (TDS-1) satellite is carried out to image the ocean sea surface height (SSH). An SSH estimation algorithm is applied to GPS-R delay waveforms over two regions in the South Atlantic and the North Pacific. Estimatesmade fromTDS-1 overpasses during a 6month(More)
1. ABSTRACT The ability to investigate properties of the sea surface by means of navigation signals has recently received growing interest from the remote sensing community. This innovative technique is known as Global Navigation Satellite System-Reflectometry (GNSS-R), and it relies on signals of opportunity transmitted from GNSS Constellations (e.g. GPS,(More)
We present the implementation of a facet-based simulator to investigate the forward scattering of L-band signals from realistic sea surfaces and its application to spaceborne ocean Global Navigation Satellite System (GNSS) Reflectometry. This approach provides a new flexible tool to assess the influence of the ocean surface roughness on scattered GNSS(More)
In this paper we analyse the GPS signals reflected by the surface of the ocean to retrieve information about the sea surface roughness, expressed in statistical terms by means of the sea surface Mean Square Slopes (MSS). Particularly, we perform Delay-Doppler mapping of real scattered GPS signals from the Surrey Satellite Technolody Ltd UK-DMC mission, and(More)
1. ABSTRACT GNSS-Reflectometry is a revolutionary approach to Earth Observation and is recently undergoing rapid advances, especially because the signals of opportunity scattered worldwide from the ocean surface can be used to investigate many important geo-physical properties in a near-real time. Global sampling and high temporal resolution of GNSS-R(More)
The backscatters power single-look waveform recorded by a synthetic aperture radar altimeter is approximated in a closed-form model. The model, being expressed in terms of parameterless functions, allows for efficient computation of the waveform and a clear understanding of how the various sea state and instrument parameters affect the waveform.