Trend Analysis of Onboard Calibration Data of Terra/ASTER/VNIR and One of the Suspected Causes of Sensitivity Degradation
Trend Analysis of Onboard Calibration Data of Terra/ASTER/VNIR and One of the Suspected Causes of Sensitivity Degradation
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Terra/ASTER/VNIR星载标定数据趋势分析及灵敏度下降的疑似原因之一
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
H. Inada
中科院分区：
文献类型：
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作者：
K. Arai;N. Ohgi;F. Sakuma;M. Kikuchi;S. Tsuchida;H. Inada
分析了 ASTER：先进星载热发射和反射辐射计/可见光和近红外辐射计：Terra 卫星上的 VNIR 的灵敏度下降趋势。针对灵敏度下降进行故障树分析。首先，通过暗电流和散粒噪声行为分析确认VNIR探测器足够稳定。然后通过光电二极管输出数据分析的灯监控器也证实了配备VNIR的校准灯的辐射度足够稳定。另一方面，通过对 VNIR 光学器件前端配备的另一个光电二极管输出数据的分析，确认 VNIR 光学器件前端的辐射亮度随着 VNIR 灵敏度的下降而下降，但光电二极管的输出在推出后一年左右就出现了缩减。由于 VNIR 输出和后来的光电二极管输出表现出几乎相同的降级，VNIR 光学透明度可能不会降级得那么严重。因此，可以说 VNIR 灵敏度下降的可能原因之一是推进器羽流。
Sensitivity degradation trend is analyzed for ASTER: Advanced Spaceborne Thermal Emission and Reflection radiometer/Visible and Near-Infrared Radiometer: VNIR onboard Terra satellite. Fault Tree Analysis is made for sensitivity degradation. Firstly, it is confirmed that the VNIR detectors are stable enough through dark current and shot noise behavior analysis. Then it is also confirmed that radiance of calibration lamp equipped VNIR is stable enough through lamp monitor of photodiode output data analysis. It is confirmed that radiance at the front of VNIR optics is, on the other hand, degraded in conjunction with sensitivity degradation of VNIR through an analysis of another photodiode output data which is equipped at the front of VNIR optics, photodiode output is scale-off at around one year after the launch though. VNIR optics transparency might not be so degraded due to the fact that VNIR output and the later photodiode output show almost same degradations. Consequently, it may say that one of possible causes of VNIR sensitivity degradation is thruster plume.