嫦娥一号干涉成像光谱仪2C级图像数据质量评价

嫦娥一号干涉成像光谱仪(IIM)获取的多波段图像数据对于月表矿物成分反演具有重要意义.从目视质量、客观参数、几何配准精度、图像质量随时间的变化情况等方面对IIM 2C级的多波段图像数据质量进行了评价.结果显示,其两端波段范围的图像质量较差,不能有效识别月表单元,中间波段图像质量较好;自然色图像显示IIM数据存在明显的横向色调不均一性.利用图像的客观评价指标(辐射精度、清晰度、信息量)将干涉成像光谱仪图像数据与美国Clementine UV-VIS多光谱图像数据进行对比分析,结果表明,IIM数据清晰度好于ClementineUV-VIS,而在方差和信息量上弱于Clementine UV-VIS.将IIM图像数据与Clementine多光谱数据统一到相同的空间分辨率,进行配准精度评价,其最大控制点配准误差为0.63 pixel.此外,还对时间跨度两个月覆盖月表同一区域的IIM图像数据从辐射精度、信息量和清晰度方面进行了评价.

Image Quality assessment for Chang’E-1 IIM 2C Data

Imaging Interferometer(IIM) onboard Chang’E-1 satellite is the first imaging spectrometer for lunar detection in China.The multi-bands image data of IIM played an important role in lunar minerals and elements retrieval.In this paper,IIM data is evaluated from several aspects including subjective image visual evaluation,objective image quality parameters,geometric precision, data quality change with time,etc.Subjective visual evaluation shows that images of short wavelength bands(band 1,2,3,4,5) and the last bands(band 31,32) in image cube had bad qualities,which may not recognize lunar surface very well,while images in the middle of the cube are much better.A phenomenon is found by RGB image that there is an image tone inhomogeneity from left to right,which may be caused by discontinuity of CCD response.IIM data(band 24) is compared with Clementine UV-VIS image data(band 2) by image evaluation parameters such as radiance precision,definition and information content.Results show that IIM data’s definition is better than Clementine UV-VIS,but its radiance precision and information content parameters are inferior.IIM data and Clementine UV-VIS data are normalized to the same spatial resolution and IMM’s registration precision is compared.The biggest error of control points’ registration is only 0.63 pixel.Besides,IIM images acquired at different time covering the same district of lunar surface were compared and evaluated through parameters of radiance precision,definition and information content,and the time span is two months.The parameters calculated are very close,illustrating that the instrument worked stably at that period.