2012, 32(3): 440-448.
doi: 10.11728/cjss2012.03.440
Abstract:
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 0.63pixel. 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.