This paper presentes an in-flight site calibration method for thermal infrared band of HJ-1B

taking advantages of Lake Qinghai test-site for the absolute radiometric calibration for thermal infrared band of HJ-1B.By using measurement data and landsat5-TM to analyze the different results between site calibration and primeval calibration

it shows that the accuracy of in-flight site calibration had been increased 0.6%—3% comparing with the primeval calibration result and the total accuracy is about 1K.Thus this new site calibration method is applicable to the in-flight absolute radiometric calibration of these sensors without the capability of detecting cold space.By the way

the accuracy of calibration for thermal infrared of HJ-1B can meet user’s requirements for the application of quantitative thermal infrared data.