基于光学遥感数据虹湾地区铁钛含量反演研究

月球表面的铁钛含量分布对月球的起源与演化研究以及月球资源的开发利用都具有重要意义.不同遥感数据获得的铁钛含量常不相同,有必要利用多种遥感数据获得月表铁钛含量,并对反演结果进行对比分析.本文利用Chandrayaan-1搭载的Moon Mineralogy Mapper（M3）两个光学周期（OP1B和OP2C）数据以及＂嫦娥一号＂搭载的干涉成像光谱仪（IIM）两套定标数据（pc1和pc2）反演虹湾地区铁钛含量.结果表明OP1B和OP2C数据反演该地区铁峰值分别为17.80wt%和17.60wt%,高于pc1的15.80wt%及pc2的14.00wt%,铁均值分别为16.91wt%和16.79wt%,高于pc1的14.11wt%及pc2的13.46wt%.OP2C数据获得虹湾地区0wt%-4wt%钛丰度百分含量最高,达74.56%,高于pc1的54.66%及pc2的62.46%,OP1B数据得到的0wt%-4wt%钛丰度百分含量最低,为37.55%.OP1B和OP2C数据反演虹湾地区钛均值分别为5.35wt%和3.16wt%,pc1和pc2数据反演该地区钛均值分别为4.25wt%和3.65wt%.极低钛和低钛玄武岩占虹湾地区玄武岩的比例约为50%和40%,主要分布于雨海纪月海物质（Im1,Im2）地层单元内;高钛玄武岩所占比例约为10%,主要分布于爱拉托逊纪月海物质（EIm）地层单元内.总体来看,遥感数据获得的玄武岩钛含量呈单峰分布,低钛玄武岩占优,与样品钛含量的双峰分布不同.虹湾地区玄武岩铁钛含量,随其年龄越来越年轻,有增加的趋势.pc2数据光度校正效果最好,pc1数据光度校正精度较低,M^3不同光学周期反射率差别较大,光度校正有待改进.

Research on extraction of FeO and TiO2 contents of the Sinus Iridum region based on optical remote sensing data

The extraction of iron and titanium contents of lunar surface is of great importance to both researches of origin and development of the Moon and exploitation and utilization of lunar resource. Iron and titanium contents extracted by various optical data are always different, it is necessary to obtain these contents through multiple optical data and analyze these results. This paper makes use of data from different optical periods （OP1B, OP2C） of Moon Mineralogy Mapper （M3） onboard Chandrayaan-1 and two calibrated data sets （pc1, pc2） of Interference Imaging Spectrometer （IIM） onboard Chang’E-1 to extract iron and titanium contents of the Sinus Iridum region. The results are as followed： FeO peak value obtained by OP1B and OP2C is 17.80wt% and 17.60wt% respectively, which is higher than pc1’s 15.80wt% and pc2’s 14.00wt%. FeO average value achieved by OP1B and OP2C is 16.91wt% and 16.79wt% respectively, higher than pc1’s 14.11wt% and pc2’s 13.46wt%. 0wt%-4wt% titanium contents percentage acquired by OP2C is 74.46%,higher than pc1’s 54.66% and pc2’s 62.46%, while OP1B’s is 37.55%. TiO2 average value obtained by OP1B and OP2C is 5.35 wt% and 3.16wt% respectively. TiO2 average value achieved by pc1 and pc2 is 4.25wt% and 3.65wt% respectively. Very low and low titanium basalt of the Sinus Iridum area nearly approach 50% and 40% respectively, which mainly locate on Im1 and Im2 units. High titanium basalt that account for nearly 10% percentage locates on EIm unit. On the whole, titanium content of basalt obtained by optical data show a unimodal distribution, low titanium basalt dominates, which differs from the bimodal distribution of the samples’ titanium. Iron and titanium contents of the Sinus Iridum’s basalt, with its age become younger, present a growing tendency. Among the four data sets, the photometric calibration of pc2 data is the best, the precision of photometric calibration of pc1 is rather low, the reflectance of various optical periods of M3 differs, and the precision of photometric calibration of M^3 data from different optical periods needs to be improved.