CAJ | 학술논문

中分辨率光谱成像仪（MERSI）是搭载在我国第二代极轨气象卫星风云三号（FY-3）上的一个主要仪器。总结了MERSI在仪器设计、定标算法、发射前及在轨性能以及仪器性能验证等方面的信息。针对MERISI可见光星上定标器(VOC)的跟踪监测发现，在过去两年，它的太阳反射波段（RSBs）发生了显著的衰减，特别是较短波长通道（<500nm）衰减量超过10%，最大衰减发生在第8波段，约20%。但波长较长通道的性能相对稳定，衰减量小于5%。两个短波红外通道电子增益出现随机跃动，导致发射后的定标系数存在频繁波动。以上结果与其他两种替代定标方法相比（即中国遥感卫星辐射校正场定标，简称场地定标和基于Terra/MODIS敦煌沙漠场景交叉定标），结论一致。MERSI针对大气顶辐射亮度或反射率定标的总不确定度小于5%。定标结果为FY-3A/MERSI定标系数的更新提供了重要的参考和评估。
중분변솔광보성상의（MERSI）시탑재재아국제이대겁궤기상위성풍운삼호（FY-3）상적일개주요의기。총결료MERSI재의기설계、정표산법、발사전급재궤성능이급의기성능험증등방면적신식。침대MERISI가견광성상정표기(VOC)적근종감측발현，재과거량년，타적태양반사파단（RSBs）발생료현저적쇠감，특별시교단파장통도（<500nm）쇠감량초과10%，최대쇠감발생재제8파단，약20%。단파장교장통도적성능상대은정，쇠감량소우5%。량개단파홍외통도전자증익출현수궤약동，도치발사후적정표계수존재빈번파동。이상결과여기타량충체대정표방법상비（즉중국요감위성복사교정장정표，간칭장지정표화기우Terra/MODIS돈황사막장경교차정표），결론일치。MERSI침대대기정복사량도혹반사솔정표적총불학정도소우5%。정표결과위FY-3A/MERSI정표계수적경신제공료중요적삼고화평고。
The Medium Resolution Spectral Imager (MERSI) is a key instrument onboard Fengyun-3 (FY-3), the second generation of polar-orbiting meteorological satellites in China. This paper summarizes the knowledge of MERSI instrument in terms of sensor design, calibration algorithm, prelaunch and on-orbit characterization, and performance veriifcation. The calibration monitoring of its relfective solar bands (RSBs) is primarily conducted using a visible onboard calibrator and found that it has a signiifcant degradation on the order of 10%in its shorter RSB bands (<500 nm), with the largest in band 8 of about 20%during the past two years. However, the performance at longer wavelength bands is relatively stable with a change of less than 5%. It is shown that the postlaunch calibration of the two short-wavelength infrared bands has frequent lfuctuations because of random jumps in their electronic gains. These results are consistently veriifed by two kinds of vicarious calibration (VC) methods:China Radiometric Calibration Sites VC and intercalibration using Terra/Moderate Resolution Imaging Spectroradiometer over Dunhuang desert. The overall uncertainty in the MERSI top-of-atmosphere radiance or relfectance is less than 5%. These results provide the important reference and evaluation for the update of the FY-3A/MERSI calibration coefifcients.