The Radiometric Stability and Scaling of Collection 6 Terra-and Aqua-MODIS VIS, NIR, and SWIR Spectral Bands
The Radiometric Stability and Scaling of Collection 6 Terra-and Aqua-MODIS VIS, NIR, and SWIR Spectral Bands
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DOI：
10.1109/tgrs.2015.2400928
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发表时间：
2015-08-01
影响因子：
8.2
通讯作者：
Gopalan, Arun
中科院分区：
文献类型：
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作者：
Doelling, David R.;Wu, Aisheng;Gopalan, Arun
中分辨率成像光谱仪（MODIS）校准小组最近发布了Collection 6（C6）辐射率，该辐射率比Collection 5（C5）有了广泛的改进。太阳散射器的重新表征、月球测量和扫描镜角度校正消除了大部分可见光通道校准漂移。在利比亚沙漠，Dome-C，和深对流云（DCC）不变的地球目标，波长小于1 μ m的可见波段校准稳定性进行了验证。Terra和Aqua C6的寿命稳定性均在1%以内，而Terra C5的大多数可见波段降解超过2%。MODIS的寿命辐射趋势的不变目标大多在1%以内，但是，特定波段的目标波动是不一致的，这表明，稳定的限制不变的目标已经达到。基于Terra和Aqua-MODIS几乎同时的最低点天桥（NSNO）辐射率比较，Terra和Aqua C6校准显示协议在1.2%以内，而C5校准超过2%。由于中分辨率成像光谱仪的仪器是相似的，相同的NSNOs被用来辐射定标的Terra辐射到Aqua。对于大多数可见光波段，地形尺度和水C6辐射是一致的，在0.5%内超过圆顶-C，DCC，并为地球同步可见光成像仪具有类似的光谱响应函数，这是用来作为转移辐射计。对于大于1 μ m的波段，仅进行了微小的校准调整，C6校准稳定在基于Libya-4的1%以内。
The Moderate Resolution Imaging Spectroradiometer (MODIS) Calibration Team has recently released the Collection 6 (C6) radiances, which offer broad improvements over Collection 5 (C5). The recharacterization of the solar diffuser, lunar measurements, and scan mirror angle corrections removed most of the visible channel calibration drifts. The visible band calibration stability was validated over the Libyan Desert, Dome-C, and deep convective cloud (DCC) invariant Earth targets, for wavelengths less than 1 mu m. The lifetime stability of Terra and Aqua C6 is both within 1%, whereas the Terra C5 degradation exceeded 2% for most visible bands. The MODIS lifetime radiance trends over the invariant targets are mostly within 1%; however, the band-specific target fluctuations are inconsistent, which suggests that the stability limits of the invariant targets have been reached. Based on Terra-and Aqua-MODIS nearly simultaneous nadir overpass (NSNO) radiance comparisons, the Terra and Aqua C6 calibration shows agreement within 1.2%, whereas the C5 calibration exceeds 2%. Because the MODIS instruments are alike, the same NSNOs are used to radiometrically scale the Terra radiances to Aqua. For most visible bands, the Terra-scaled and Aqua C6 radiances are consistent to within 0.5% over Dome-C, DCC, and for geostationary visible imagers having similar spectral response functions, which are used as transfer radiometers. For bands greater than 1 mu m, only minor calibration adjustments were made, and the C6 calibration is stable within 1% based on Libya-4.