Journal of Geo-information Science >
The Research and Assessment of Topographic Registration and Correction of Chang’E-1 IIM Data Based on LRO LOLA DEM Data
Received date: 2014-07-09
Request revised date: 2014-08-12
Online published: 2015-01-05
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The characteristics of the visible and near-infrared reflectance from lunar surface are key information for the inversion and mapping of chemical elements in lunar exploration. Due to the dimply topography, hyperspectral dataobtained from IIM should be introduced with topographic correction before the application of practical inversion to get the actual reflectivity information. There ported longitudes and latitudes of the IIM data generally did not match with the conventional data from the LOLA DEM. Consequently, the accuracy of the topographic correction might be affected and decreased. In this paper, a case study was done related to the lunar crater. More specifically, a certain number of ground control points in a crater with same characteristic were selected for both images to match the IIM data and LOLA DEM data. The results from polynomial correction method were different from the correction results calculated directly from lunar longitude and latitude. There was approximately 3.5 pixels’ offset in the direction of longitude and about 1.95 pixels’ offset in the direction of latitude between IIM data and LOLA DEM data. The conventional topographical correction used on earth (i.e. C correction method) was introduced for a possible topographical correction on the moon, where there is almost no atmosphere scattering. The results showed that the performance of the matched topographical correction data was much better than those from unmatched data. After the application of registration and C correction, the slope of the linear correlation equation between the incident angle cosine value and the reflectance was reduced by 89.4 percent, the terrain effects of the shadow area and the highlight area on the lunar surface was eliminated. We concluded that the actual reflectivity information from lunar surface could be closely assessed after applying registration and topographic correction to IIM data, which could provide a sound basis for the inversion of chemical elements and minerals based on IIM data.
Key words: Chang’E-1; IIM; LOLA; registration; C Correction; topographic correction
MA Mingliang , WANG Chao , SHI Runhe , GAO Wei . The Research and Assessment of Topographic Registration and Correction of Chang’E-1 IIM Data Based on LRO LOLA DEM Data[J]. Journal of Geo-information Science, 2015 , 17(1) : 118 -125 . DOI: 10.3724/SP.J.1047.2015.00118
Fig. 1 Thesketch map of the study area.图1 研究区域示意图 |
Fig. 2 The flow chart of data processing图2 数据处理流程图 |
Fig. 3 The overlay chart of the DEM and IIM reflectance image before (a) and after (b)registration.图3 配准前后IIM影像与DEM影像叠置图比较 |
Tab. 1 Comparison of the sample numbers and line numbers of the ground control points in the IIM image before and after registration表1 配准前、后IIM影像特征点行列号比较 |
特征点号 | 配准前行号 | 配准后行号 | 行偏移量 | 配准前列号 | 配准后列号 | 列偏移量 |
---|---|---|---|---|---|---|
1 | 115 | 111 | 4 | 26 | 27 | 1 |
2 | 124 | 120 | 4 | 332 | 334 | 2 |
2 | 69 | 65 | 4 | 163 | 165 | 2 |
4 | 81 | 77 | 4 | 142 | 144 | 2 |
5 | 98 | 94 | 4 | 123 | 125 | 2 |
6 | 12 | 9 | 3 | 151 | 153 | 2 |
7 | 162 | 158 | 4 | 245 | 247 | 2 |
8 | 28 | 25 | 3 | 267 | 269 | 2 |
9 | 50 | 46 | 4 | 77 | 79 | 2 |
10 | 35 | 32 | 3 | 298 | 300 | 2 |
11 | 63 | 60 | 3 | 352 | 354 | 2 |
12 | 148 | 145 | 3 | 324 | 326 | 2 |
13 | 47 | 44 | 3 | 103 | 105 | 2 |
14 | 122 | 118 | 4 | 57 | 59 | 2 |
15 | 101 | 98 | 3 | 296 | 298 | 2 |
16 | 160 | 157 | 3 | 311 | 313 | 2 |
17 | 149 | 145 | 4 | 324 | 326 | 2 |
18 | 90 | 87 | 3 | 353 | 355 | 2 |
19 | 95 | 92 | 3 | 88 | 90 | 2 |
20 | 150 | 146 | 4 | 207 | 209 | 2 |
平均偏移量 | 3.5 | 1.95 |
Fig. 4 The reflectance image of band 20 of IIM: the original image (a), spatial unmatched image (b), and spatial matched image (c)图4 校正前后IIM第20波段的影像对比 |
Fig. 5 (a) is the original average reflectance of IIM 26 bands in the shadow area (the top red polygon in Fig. 4(a))and the highlight area (the bottom red polygon in Fig. 4 (a)). (b) is the correction average reflectance of IIM 26 bands in the shadow area and the highlight area.图5 阴影区域(图4(a)的右上红色方框)和阳坡高亮区域(图4(a)的左下红色方框)校正前、后26个波段波长的平均反射率 |
Fig. 6 The scatter plots of the reflectance from the original image (a)and topographic corrected image (b) of the band 20 IIM image.图6 IIM第20波段校正前、校正后影像的反射率散点图 |
Fig. 7 The histograms of the reflectance from the original image (a) and corrected image (b)of the band 20 IIM image图7 校正前、校正后IIM第20波段反射率值分布直方图 |
Tab.2 Comparison between the statistical parameters of the original and topographic corrected bands of the IIM image表2 月表地形校正前后各个波段IIM影像两种统计参数比较 |
IIM波长(nm) | 校正前平均值 | 校正后平均值 | 校正前标准差 | 校正后标准差 |
---|---|---|---|---|
522 | 0.1733 | 0.1755 | 0.0464 | 0.0375 |
531 | 0.1738 | 0.1760 | 0.0468 | 0.0376 |
541 | 0.1796 | 0.1819 | 0.0477 | 0.0382 |
550 | 0.1815 | 0.1838 | 0.0473 | 0.0378 |
561 | 0.1829 | 0.1851 | 0.0484 | 0.0386 |
571 | 0.1864 | 0.1888 | 0.0488 | 0.0388 |
582 | 0.1885 | 0.1909 | 0.0495 | 0.0393 |
594 | 0.1924 | 0.1949 | 0.0504 | 0.0400 |
605 | 0.1955 | 0.1980 | 0.0507 | 0.0400 |
618 | 0.1993 | 0.2018 | 0.0515 | 0.0406 |
631 | 0.2017 | 0.2042 | 0.0520 | 0.0409 |
644 | 0.2049 | 0.2075 | 0.0526 | 0.0413 |
658 | 0.2048 | 0.2074 | 0.0516 | 0.0403 |
673 | 0.2095 | 0.2122 | 0.0531 | 0.0415 |
688 | 0.2095 | 0.2152 | 0.0531 | 0.0418 |
704 | 0.2167 | 0.2195 | 0.0549 | 0.0429 |
721 | 0.2206 | 0.2234 | 0.0557 | 0.0432 |
738 | 0.2238 | 0.2267 | 0.0560 | 0.0436 |
757 | 0.2266 | 0.2296 | 0.0563 | 0.0435 |
776 | 0.2289 | 0.2320 | 0.0564 | 0.0435 |
797 | 0.2303 | 0.2334 | 0.0559 | 0.0431 |
818 | 0.2312 | 0.2344 | 0.0554 | 0.0426 |
841 | 0.2305 | 0.2337 | 0.0542 | 0.0413 |
865 | 0.2306 | 0.2339 | 0.0536 | 0.0407 |
891 | 0.2321 | 0.2355 | 0.0532 | 0.0403 |
918 | 0.2342 | 0.2376 | 0.0535 | 0.0406 |
The authors have declared that no competing interests exist.
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