首页 >  , Vol. , Issue () : -

摘要

全文摘要次数: 188 全文下载次数: 258
引用本文:

DOI:

10.11834/jrs.20210071

收稿日期:

2020-03-18

修改日期:

2020-10-13

PDF Free   EndNote   BibTeX
海洋一号卫星水色水温扫描仪红外信息获取技术
范文龙, 黄小仙, 傅雨田
中国科学院上海技术物理研究所
摘要:

自2000年至今,我国已发射了海洋一号A、B、C与D四颗太阳同步海洋光学遥感卫星。对海温分布与变化的探测是海洋一号卫星主载荷水色水温扫描仪(简称水色仪,COCTS)的主要任务之一。考虑到对海冰和海洋上空台风等气象要素的同时探测,实际水温探测通道的动态范围要求涵盖200K?320K的温度区间。由于某些洋面区域微弱温度的变化将会导致严重天气灾害的发生,因此海温探测通道还需满足探测灵敏度与定量化的精度要求。本文旨在依据技术指标要求,设计水色仪红外通道的信息获取电路,包括对探测器微弱信号进行放大的前置放大电路,消除基础电平以提高动态范围的交流放大器,以及实现信号的直流恢复与动态范围调整的通道放大电路。基于对所使用的光导型红外探测器工作机理的研究,结合水色仪的系统组成与特性,为确保同时满足高动态范围与高灵敏度这一对相互矛盾的指标要求,通过理论分析计算、电路仿真等方法,确定各级放大电路的形式及参数。为实现整个扫描视场的稳定基准电平探测与单像素信号探测,设计相应的高通与低通滤波器,并在真空环境模拟实验室对水色仪的系统性能进行测定,以验证信息获取电路设计的合理性。在实验室进行的红外辐射定标结果表明,水色仪两个红外通道的动态范围分别覆盖了177K~327K和173K~324K,均满足200K~320K的技术指标要求;两个红外通道在整个动态范围内的噪声等效温差(NETD)分布在20mK~110mK之间,而在考核位置300K处则达到了21mK~34mK,远优于0.2K的技术指标要求。空间测试环境较实验室复杂,测量精度亦有一定的差异。在轨测试结果表明,两个红外通道的动态范围分别覆盖了186K~328K和185K~326K,在整个动态范围内的NETD根据所选目标区域开窗大小的不同分布在50mK~110mK之间,性能优于技术指标要求。红外通道能够实时跟踪星上黑体信号随时间与周围环境的变化,可据此来对红外通道的定标系数进行即时修正,从而达到预期的在轨实时辐射定标的目的,为定量化反演海温奠定了基础,并能获取且制作出高质量的全球海温产品。

Infrared Information Acquisition Technology of Chinese Ocean Color and Temperature Scanner of HY-1 Satellite
Abstract:

Since 2000, China has launched four sun-synchronous ocean optical remote sensing satellites, Ocean-1A, 1B, 1C and 1D. The detection of sea surface temperature (SST) distribution and variation is one of the main tasks of Chinese ocean color and temperature scanner (COCTS), which is the main load of Ocean-1 satellite. Considering the detection of sea ice, typhoon and other meteorological elements over the ocean, the dynamic range of the actual water temperature detection channel is required to cover the temperature range of 200K to 320K. The variation of temperature in some ocean areas will lead to severe weather disasters, so SST detection channels need to meet the requirements of detection sensitivity and quantification accuracy. Objective: The purpose of this paper is to design the information acquisition circuit of infrared channel for COCTS according to the technical requirements, including the pre-amplifier circuit to amplify the weak signal of the detector, the AC amplifier which eliminates the basic level to improve the dynamic range, and the channel amplifier circuit which can realize the DC recovery and dynamic range adjustment of the signal. Method: Based on the study of the working mechanism of the photoconductive infrared detector used, and combined with the system composition and the characteristics of COCTS, in order to ensure that the contradictory requirements of high dynamic range and high sensitivity are met at the same time, the form and parameters of each stage amplifier circuit were determined on the basis of theoretical analysis, calculation and simulation. In order to achieve the stable reference level detection and single pixel signal detection of the whole field of view, the corresponding high-pass and low-pass filter are designed. The system performance of COCTS will be measured in the vacuum environment simulation laboratory, to verify the reasonability of information acquisition circuit design. Result: The results of the infrared radiometric calibration in the laboratory show that the dynamic range of the two infrared channels covers 177K to 327K and 173K to 324K respectively, and both meet the technical requirements of 200K to 320K. The noise equivalent temperature difference (NETD) of the two infrared channels in the whole dynamic range is between 20mK and 110mK. At the appraisal position of 300K, NETD has reached 21mK to 34mK, which is much better than the technical requirements of 0.2mK. Space test environment is more complex than the laboratory, and there are also some differences in measuring accuracy. The results of in orbit test show that the dynamic range of the two infrared channels is 186K to 328K and 185K to 326K respectively, and the NETD in the whole dynamic range is between 50mK and 110mK according to the window size of the selected target area. The performance is better than the technical requirements. Conclusion: The infrared channel can track the change of the blackbody signal on the satellite with the time and the surrounding environment changing, so the calibration coefficient of the infrared channel can be corrected in real-time. The expected goal of real-time radiometric calibration in orbit can be achieved. This lays a foundation for the quantitative inversion of SST, and can obtain and make high-quality global SST products.

本文暂时没有被引用!

欢迎关注学报微信

遥感学报交流群 分享按钮