为了满足中国环保、国土、农业、气象、减灾等行业对地表温度遥感高精度监测的需求，近些年来中国长波红外空间光学遥感器空间分辨率从公里尺度提高到十米尺度分辨率，定量化应用的需求也越来越高。高精度的辐射定标是保证红外数据定量化应用的关键，本文通过全链路分析了影响辐射定标精度的因素，结合某型号任务的研制过程的具体实际，分析了主要影响因素的优化方法，包括星上定标方案优化、提高星上定标黑体控温精度和标定精度、提升长波探测器性能、提高长波探测器焦面控温精度等措施提高相机的性能和输出稳定性，并通过该型号真空辐射定标试验对辐射定标精度、系统定标响应情况进行了验证，试验结果绝对辐射定标精度为0.8 K@300 K，达到国内空间分辨率小于100 m的同类长波红外空间光学遥感器的较高水平。本文介绍的长波红外空间光学遥感器性能提升方法可为今后同类遥感器的研制及辐射定标提供参考借鉴，同时提供的定标试验验证结果也可以为同类红外卫星在轨应用提供参考。

In order to meet the needs of high-precision monitoring of surface temperature remote sensing in environmental protection, land, agriculture, meteorology, disaster reduction and other industries of our country, the spatial resolution of our country’s long-wave infrared optical remote sensors has been increased from kilometer scale to ten-meter scale in recent years. The demand for quantitative applications is also increasing gradually. High-precision radiation calibration is the key to ensuring the quantitative application of infrared data. The detector of long wave infrared camera is limited by the chip material, chip preparation process, readout circuit design and production capacity and other reasons. Although the long wave infrared detector is constantly improving and developing, there are still some problems in varying degrees, such as large dark current, non-uniform response, low response and low temperature response, which directly affect the performance and radiometric calibration accuracy of long wave infrared camera.This article analyzes the factors that affect the accuracy of radiation calibration through the entire link. Combining with the specific development process of a certain model task, this article analyzes the optimization methods of the main influencing factors, including the optimization of the on-board calibration scheme, the improvement of temperature controlling accuracy and calibrating accuracy of the on-board blackbody calibration, the improvement of the performance of the long-wave detector and the improvement of the temperature controlling accuracy of the long-wave detector on the focal plane to improve the performance and output stability of the camera. The radiation calibration accuracy and the response state of system calibration has been verified through the vacuum radiation calibration test of this model. The test results show that the response slope of the radiometric calibration equation of the long wave infrared camera is effectively improved (from better than 45 of GF-5 01 satellite to better than 125 of GF-5 02 satellite), the output stability of the camera system is improved (DN value fluctuation is reduced from 20-30DN of GF-5 01 satellite to 1-2 DN of GF-5 02 satellite), and the accuracy of radiometric calibration is improved (from 1 K@300 K of GF-5 01 satellite decreased to 0.8 K@300 K of GF-5 01 satellite）.It reaches a high level among the same type of domestic long-wave infrared space optical remote sensors with a spatial resolution of less than 100 m. The performance improvement method of long-wave infrared space optical remote sensor introduced in this article can provide reference for the development and radiation calibration of similar remote sensors in the future. The calibration test verification results provided in this article can also provide references for the in-orbit applications of similar infrared satellites.