Analysis of backscattering measurement error of CSCAT
The CFOSAT(China-France Oceanography SATellite)SCATterometer(CSCAT)adopts a pioneering fan-beam rotary scanning system to provide averaged backscattering coefficient of different combinations of various incidence angles and azimuth angles,obtaining high-quality retrieval information of ocean surface wind field.Despite the innovative system design and scanning mode,certain inaccuracies remain in measuring backscattering coefficient,especially under large incidence angles and low wind speed conditions.Then the Kp value,representing the normalized standard deviation,reflects the variation of measurement error with wind speed conditions and incidence angles.The NWP(numerical weather prediction)Ocean Calibration(NOC)method is applied during the processing of L1B-L2A data to effectively improve the measurement accuracy.The K of slices in L1B data indicates that the accuracy is better in the condition of about 40° incidence angle and medium wind speed.The error analysis of wind vector cells(WVCs)in L2A data shows that the measurement error is relatively large at low wind speed.Additionally,a consistent estimate of geophysical noise is obtained through recalibration data,and the geophysical noise accounts for 20％-30％after excluding the very low wind speed measurement.
国家科技期刊平台
NSTL
万方数据
维普
