Inflight Calibration of the NEAR Multispectral Imager: II. Results from Eros Approach and Orbit
✍ Scribed by Scott Murchie; Mark Robinson; Deborah Domingue; Han Li; Louise Prockter; S.Edward Hawkins III; William Owen; Beth Clark; Noam Izenberg
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 340 KB
- Volume
- 155
- Category
- Article
- ISSN
- 0019-1035
No coin nor oath required. For personal study only.
✦ Synopsis
During the Near-Earth Asteroid Rendezvous (NEAR) spacecraft's investigation of asteroid 433 Eros, inflight calibration measurements from the multispectral imager (MSI) have provided refined knowledge of the camera's radiometric performance, pointing, and light-scattering characteristics. Measurements while at Eros corroborate most earlier calibration results, although there appears to be a small, gradual change in instrument dark current and flat field due to effects of aging in the space environment. The most pronounced change in instrument behavior, however, is a dramatic increase in scattered light due to contaminants accumulated on the optics during unscheduled fuel usage in December 1998. Procedures to accurately quantify and to remediate the scattered light are described in a companion paper (Li et al. 2002, Icarus 155, 00-00). Acquisition of Eros measurements has clarified the relative, filter-to-filter, radiometric performance of the MSI. Absolute radiometric calibration appears very well constrained from flight measurements, with an accuracy of ∼5%. Pointing relative to the spacecraft coordinate system can be determined from the temperature of the spacecraft deck with an accuracy of ∼1 pixel.