Wide-angle infrared Dual-mode line/area Array Scanner (WiDAS) is an airborne remote sensing instrument designed to acquire multi-angle infrared remote sensing data, which is one of the essential observation in the simultaneous remote sensing and ground-based experiment in the Heihe river basin. After a brief introduction of the research background and hardware structure, the processing algorithms and product system for WiDAS thermal data are subsequently proposed according to the characteristics of WiDAS imaging system. In the end, the radiant directionality of six typical ground objects is extracted from calibrated and georectified WiDAS data, which indicates WiDAS as a good data source for study of land surface radiant directionality in MIR and TIR band.