Design of a dayight star camera system

摘要

Abstract: This paper describes the design of a camera system capable of acquiring stars during both the day and night cycles of a high altitude balloon flight. The camera system will be filtered to operate in the R and I bands, and simulations have been run using MODTRAN atmospheric code to determine the worse case sky brightness at 35k. With a worse case daytime sky brightness of 2 $MUL 10$+$MIN@5$//sr/$mu@m at 600nm, the sensitivity of the camera system will allow acquisition of at least 1-2 stars/degrees$+2$/ at star magnitude limits of 7.8-8.1. The system will have an F2.8, 64.3mm diameter lens and a 1340 $MUL 1037 CCD digitized to 12 bits. The CCD is comprised of 6.8$mu@m $MUL 6.8$mu@m pixels with a well depth of 45,000 electrons and quantum efficiency of 0.54 at 700nm. The camera's field-of-view will be 6.33 degrees$+2$/ and provide attitude knowledge to 8 arcsec or better. A test flight of the system is scheduled for fall 1999. !7