Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： The scatterometer onboard Haiyang-2 satellite (HY-2 SCAT) is a rotating pencil-beam scatteromter. It provides 4 times of radar cross-section (sigma0) measurements at different azimuth/incidence angles over a wind vector cell, in order to determine the near-surface wind field using the Geophysical Model Function (GMF). To achieve the required wind vector accuracy, radar cross-section measurements must be calibrated within a few tenths of a decibel (within 0.5 dB). In this paper, HY-2 SCAT is calibrated using natural land-extended targets over different regions and is compared with OSCAT. sigma~0 errors over different azimuth angles are eliminated. The error sources of the measurements are analyzed and the pointing errors are compared with that estimated from measurements of Altimeter onboard HY-2 satellite.
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-03
Abstract： The scatterometer onboard HY-2 satellite is calibrated using Numerical Ocean Calibration and its retrieval winds after calibration are validated from 130 global buoys and winds from the European Centre for Medium-Range Weather Foresting Numerical Weather Prediction model using triple-collocation during December 2012, resulting in 3112 collocated triplets. The KNMI QC flag is used to collocate the data without rain efforts. It is found that functional relationship employing the error-in-variables method is more accuracy than that using linear regression for the validation of retrieval wind from HY-2 scatterometer. Moreover, using the wind component domain is confirmed to be favourable. It is shown that the uncertainties after ocean calibration is less than 0.15dB, resulting in 0.2m/s systematic wind effects. For both zonal and meridional winds, the similar wind fields comparing with buoys and ECMWF indicate that the effective of the calibration and high quality of the retrieval winds. �2015, Chinese Institute of Electronics. All right reserved.
Peer Review Status:Awaiting Review
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