Thermal Discharge Temperature Retrieval and Monitoring of NPPs Based on SDGSAT-1 Images

High-accuracy sea surface temperature (SST) retrieval near nuclear power plants (NPPs) is one of the most significant indicators for evaluating marine ecological environment quality, monitoring real-time situation thermal discharge, and supporting planning decisions. However, complex computations, inaccessible vertical profile atmosphere, uncertainty atmospheric data increase error SST retrieval. Additionally, influenced by their low spatial resolution, widely used AVHRR/MODIS remote sensing images (RSIs) are unable to retrieve detailed distribution in small scale regions such as coastal NPPs. In this paper, we propose a simplified split-window-based method (the SW method) suitable SDGSAT-1 30 m infrared spectrometer (TIS) RSIs. Specially, only needs transmittance emissivity counteracting average monitor discharge offshore First, geometric radiometric calibrated multi-spectral cloudless target selected obtain corresponding apparent radiance Second, accordance with red near-infrared (NIR) bands RSIs, calculated distinguish water from land. Next, determine parameters weather conditions region at imaging time. Finally, according theory surface-atmosphere radiative transfer, retrieved proposed method, results compared those conventional transfer equation (RTE), mono-window (MW), nonlinear (NLSST) algorithms. The experimental indicate that split-window algorithms (i.e., NLSST) generally higher than single-channel RTE MW). difference between algorithm NLSST within 0.5 °C. addition, can seasonal variation This article first attempt quantitative small-scale based on obtained TIS multispectral imager (MII), therefore, provide an effective reference monitoring.