Citation
Abstract
We report on laboratory emulator experiments performed to assess the feasibility of infrared (IR) Earth image tracking for optical communications. A quantum-well infrared photodetector (QWIP) is evaluated and characterized for this purpose. For proof of concept, an emulator is designed and implemented in the laboratory to generate IR Earth images over the range of 0.38 to 40 AU at the focal-plane array of the QWIP camera to evaluate the feasibility of using IR Earth images as optical communication pointing references. IR Earth images measured from the test-bed emulator are compared with the corresponding images derived from Earth thermal modeling, and the two are found to be in good agreement. IR Earth image nonuniformity is also emulated in the laboratory test bed, demonstrating that for characteristic deep-space optical apertures, the image is dominated by the Earth thermal nonuniformity at short distances (<2 AU) but is overwhelmed by diffraction blurring beyond 4 AU. Preliminary laboratory test-bed emulator investigation on centroiding accuracy of IR Earth center detection shows improved centroiding accuracy with increasing image size and IR signal level.
Keywords
Details
- Volume
- 42-171
- Published
- November 15, 2007
- Pages
- 1–21
- File Size
- 1.7 MB