GOES‐16/ABI Thermal Emissive Band Assessments Using GEO‐LEO‐GEO Double Difference
GOES‐16/ABI Thermal Emissive Band Assessments Using GEO‐LEO‐GEO Double Difference
复制标题
使用 GEO-LEO-GEO 双差值进行 GOES-16/ABI 热发射带评估
作者：
Tiejun Chang;X. Xiong
地球同步卫星（GOES）-16/高级基线成像仪（ABI）和Himawari-8/高级Himawari成像仪（AHI）比以前的GOES上的成像仪有了显着的改进。它们的波段7-16是覆盖3.9 - 13.3 μm光谱范围的红外通道，子点空间分辨率为2 km。它们对热发射带（TEB）的光谱覆盖范围几乎相同，两种仪器都采用了类似的校准策略，使用机载黑体和空间外观。这两种仪器的比对将有助于它们的校准评估和产品质量的提高。GOES-16于2016年11月19日发射，最初是在西经89.5度的测试位置，并于2017年12月11日到达其操作位置（西经75.2度）。Himawari-8航天器于2014年10月7日发射，观测重点是亚太地区。在这项工作中，他们的TEB测量的相互比较使用双差与水中分辨率成像光谱仪（MODIS）。选择相同类型的场景，这两个仪器，并与Aqua MODIS匹配波段的测量值与最近的观测时间进行比较。对视角效应进行了校正，并对它们的光谱失配效应进行了估计。分析了该方法对场景均匀性的依赖性。对于条带10（7.35 μm）、11（8.44 μm）、12（9.64 μm）和14（11.24 μm），ABI‐AHI差异在0.3K以内，而对于条带15（12.38 μm）和16（13.28 μm），差异高达0.8K。对于所有TEB，ABI精度优于AHI，并且其图像导航和配准精度相当。总体而言，搬迁前后的ABI表现是一致的。
Geostationary satellite (GOES)‐16/Advanced Baseline Imager (ABI) and Himawari‐8/Advanced Himawari Imager (AHI) represent a significant improvement over the imagers on board previous GOES. Their bands 7–16 are infrared channels covering the 3.9‐ to 13.3‐μm spectral range and with a subpoint spatial resolution of 2 km. Their spectral coverage of the thermal emissive bands (TEBs) is almost identical, and both instruments employ similar calibration strategies using an on‐board blackbody and a space look. The intercomparison between the two instruments will be very helpful for their calibration assessments and their product quality enhancements. GOES‐16 was launched on 19 November 2016, initially to a test position at 89.5° west and reached its operational position (longitude of 75.2° west) on 11 December 2017. The Himawari‐8 spacecraft was launched on 7 October 2014 and the observation focuses on Asia‐Pacific region. In this work, an intercomparison of their TEB measurement is performed using double difference with Aqua Moderate Resolution Imaging Spectroradiometer (MODIS). The same type of scenes are selected for the two instruments, and their measurements with the closest observation times are compared with Aqua MODIS matching bands. The view angle effect is corrected and their spectral mismatching effect is estimated. The dependence on the scene uniformity is analyzed. The ABI‐AHI differences are within 0.3K for bands 10 (7.35 μm), 11 (8.44 μm), 12 (9.64 μm), and 14 (11.24 μm), and up to 0.8K difference for bands 15 (12.38 μm) and 16 (13.28 μm). The ABI precision is better than AHI for all TEB and their image navigation and registration precisions are comparable. In general, the ABI performances before and after relocation are consistent.