Click image for larger TIF file: 936K
Click image for larger TIF file: 936K
The Multispectral Imager (MSI) provides visible and near-infrared images of the asteroid surface, to determine asteroid shape, morphology, and color properties. It incorporates f/3.4 radiation-hardened refractive optics and an eight-position filter wheel. Seven spectral filters on the wheel, at 450 nanometers (nm) to 1050 nm, are chosen primarily to discriminate iron-containing silicate minerals. There is also one broadband filter for low-light imaging and optical navigation - that is, steering of the spacecraft by the stars. The field of view of 51.5 mrad x 39.4 mrad (2.95° x 2.26°) is divided into 537 x 244 pixels (each 162 x 96 mrad), giving a 10 x 16 m resolution at 100 km. The CCD is electronically shuttered and allows manually commandable exposure times of 0 to 999 ms. Automatic exposure time control is also available. Outputs are digitized to 12 bits per pixel, so an uncompressed image is 1.6 megabits (Mb) in size. An image rate of 1 per second (1 Hz) can be sustained using a dedicated high speed link to the spacecraft recorders. To use recorder space and downlink bandwidth more efficiently, various forms of data compression are selectable by command.
MSI NIS NLR XGRS MAG RS
