以MODIS红外谱段数据为基准,对高光谱红外谱段数据进行辐射交叉定标试验,同时运用高光谱红外谱段数据对近海海表水温进行了评估试验.交叉定标数据选取2012年—2013年冬、夏两季各一幅代表性图像,MODIS与高光谱红外谱段数据成像时间均为同一天白天.实验结果表明,天宫一号高光谱红外谱段数据与MODIS数据具有极好的相关性,相关系数R大于0.95;在此基础上建立了基于MODIS 32波段的辐亮度线性回归校正方程,并用于海表温度反演、检测自然与人工扰动造成的海表温度异常.基于校正数据反演的中国南北典型冬、夏代表性季节的海表温度与常识较为一致.由此表明,基于MODIS交叉定标的天宫一号数据可用于实际的业务化定量评估;同时,由于空间分辨率较高,天宫一号高光谱红外谱段数据在海水精细空间动态变化检测上表现出极好的性能.

Radiometric cross-calibration of infrared band was performed between MODIS and Tiangong-1, and then calibrated Tiangong-1 data was used to monitoring the coastal Sea Surface Temperature (SST). Quasi-simultaneous MODIS and Tiangong-1 infrared images in winter and summer acquired in 2012 and 2013, were selected for cross-calibration test. The results show that radiance of Tiangong-1 infrared band was highly correlated to that of MODIS bands in the spatially matched regions (R>0.95), and accordingly, a linear radiance-correcting function for Tiangong-1 was established against the Band 32 of MODIS. The radiometric-calibrated Tiangong-1 imageries were then used to retrieve the SST of coastal waters: the temperature were consistent with the real sea surface conditions; credited to the high spatial resolution of Tiangong-1 infrared data, the anomalies in SST due to natural or human disturbance were clearly shown, e.g., the thermal effluent of cooling waters from coastal power plant, which suggests that Tiangong-1 has the potential in water temperature monitoring for the spatially complex coastal zone.