一种提高空间遥感相机宽温度场测温精度方法

摘要

文中从空间光学遥感相机控温系统对宽温度场、 高精度的温度测量需求出发,分析了基于NTC型热敏电阻测温电路的测温精度.当温差范围为120℃,在12bit量化的条件下,该电路无法全程满足测温精度要求.在此基础上,本文提出了一种基于NTC型热敏电阻和压控放大器的变增益测温电路,并对该电路的工作原理以及达到的测量效果进行了分析,在120℃温差范围内,该电路的测温精度均能满足±0.1℃,结果表明该方法能够有效的提高系统测温精度.%In this paper, the temperature measurement accuracy of the NTC (Negative temperature coefficient) thermistor circuit is analyzed which is based on the requirements of wide temperature-field and high precision space optics remote sensing camera. When the temperature difference range is 120℃, the circuit can not meet the requirements of the whole process in the quantization condition of 12 bit. On this basis, this paper presents a variable-gain temperature measurement circuit based on NTC thermistor and VCA (voltage controlled amplifier ). The principle of the circuit and the improvement of the measurement results are analyzed, in 120 ℃ difference range, the measurement precision of the circuit can meet ±0.1 ℃. The results show that the method can effectively improve the accuracy of temperature measurement.