基于TES算法研究勇气号登陆点火星表面的温度特性

Study on Temperature Characteristic of Mars Surface Where Spirit Landed Based on TES Algorithm

热红外高光谱遥感已经成为火星探测中主要的探测手段。基于温度与发射率分离(TES)算法研究了火星漫游车勇气号登陆点的温度特性。首先,对TES算法中的最大最小值差(MMD)模型进行了修正,利用ASU光谱库中102种火星上存在可能性比较大的矿物光谱拟合得到MMD修正模型。对采用MMD修正模型的TES算法进行了验证,得到的温度反演误差在1K以内。利用勇气号前240天的微小型热辐射光谱仪(Mini-TES)观测数据分别对火星的短期温度变化和季节性温度变化进行了分析。火星白天最高温出现在火星本地时间(LTST)13点到14点之间,昼夜温差大。火星白天平均温最低出现在第190天左右,温度有明显的季节性。

Thermal hyperspectral remote sensing has been a main detection way in Mars exploration. This article study the temperature characteristic of Mars surface where Mars land rover ＂Spirit＂ landed based on TES （Temperature and Emissivity Separation） algorithm. It firstly amended the MMD module used in the TES algorithm, derived a new MMD module through fitting 102 mineral spectra gotten from the ASU spectral library which may exist on Mars very possibly. Then validation of the TES algorithm that used new MMD module was executed and the temperature inversion precision arrived at 1K. After that, it analyzed the short-term and season change of Mars surface temperature using first 240 days＇ data observed by Miniature Thermal Emission spectrometer （Mini-TES） which was carried by Spirit Mars land rover. The high- est temperature of Mars appeared at 1300 - 1400 LTST （ local true solar time） , and there was large difference in temperature between day and night. Mars lowest average daytime temperature was found at the 190＇s day and Mars surface temperature has obvious seasonal change.