CAJ | 학술논문

为了对刚刚发射的风云三号A星(FY-3A)极轨气象卫星的扫描辐射计(VIRR)进行在轨定标,于2008年9月在甘肃敦煌进行了中国遥感卫星辐射校正试验.使用ASD FR光谱仪测量场地地表反射比,CE318太阳光度计测量气溶胶光学厚度(AOD),并用敦煌国家气候观象台同步加放的探空观测数据计算水汽总量(TWC),获取了3天的有效试验数据.采用反射比基法并配合新的地表反射比修正算法开展定标,其中过境时刻地表反射比由陆表各向异性二向反射比模型算法(AMBRALS)计算并用实测的地表反射比数据修正;表观反射比由6S模型计算.结果表明,在非水汽吸收通道计算得到的多天定标斜率很稳定(相对标准差在2.6%以内).与发射前相比,不同通道的定标系数在7.73%～21.52%变化.使用定标结果计算了23种观测目标的表观反射比,与TERRA/MODIS相应通道结果一致,表明了定标算法的准确性.
위료대강강발사적풍운삼호A성(FY-3A)겁궤기상위성적소묘복사계(VIRR)진행재궤정표,우2008년9월재감숙돈황진행료중국요감위성복사교정시험.사용ASD FR광보의측량장지지표반사비,CE318태양광도계측량기용효광학후도(AOD),병용돈황국가기후관상태동보가방적탐공관측수거계산수기총량(TWC),획취료3천적유효시험수거.채용반사비기법병배합신적지표반사비수정산법개전정표,기중과경시각지표반사비유륙표각향이성이향반사비모형산법(AMBRALS)계산병용실측적지표반사비수거수정;표관반사비유6S모형계산.결과표명,재비수기흡수통도계산득도적다천정표사솔흔은정(상대표준차재2.6%이내).여발사전상비,불동통도적정표계수재7.73%～21.52%변화.사용정표결과계산료23충관측목표적표관반사비,여TERRA/MODIS상응통도결과일치,표명료정표산법적준학성.
In order to calibrate the Visible and Infrared Radiometer (VIRR) of the Feng Yun 3A (FY-3A) polar orbit meteorological satellite, the China Remote Satellite Radiometric Calibration Experiment was held in September, 2008 at Dun-huang site, Gan-su province, China. By taking an ASD FR spectrometer to measure the vertical reflectance of 11 synchronization points in Dun-huang site, a sun photometer CE318 to measure the Aerosol Optical Depth (AOD) and using the sounding data measured by Dun-huang National Climatic Station synchronously to calculate the Total Water Contents (TWC),the efficient experiment data were totally obtained for 3 days. The calibration was undertaken by combined the reflectance base method with a new reflectance correction method,in which the directional reflectance at the moment of passing a platform was calculated by the Algorithm for Modeling Bidirectional Reflectance Anisotropies of the Land Surface (AMBRALS) and corrected by the reflectance measured from experiments.Moreover, the apparent reflectance was calculated by a 6S model. Obtained results show that the relative standard deviation (RSD) of the calibration coefficients is less than 2.6%. Compared to the pre-launch calibration method, the post-launch calibration has changed about 7.73%～21.52% in different bands. The apparent reflectances of 23 targets by FY-3A/VIRR are compared with that by TERRA/MODIS, which that they are coincident well and proves the calibration algorithm is veracious.