<title>Overview of contamination effects on the performance of high-straylight-rejection telescopes via ground measurements</title>

Abstract

SSG has investigated the effects of contamination on the straylight rejection performance of many state of the art sensors. Contamination degradation has been measured during standard ground operations and storage. SSG has also modeled the impacts of contamination on the performance of several infrared telescopes such as CIRRIS 1A, CLAES, SPIRIT II & III, as well as visible systems such as the Space Based Visible (SBV) sensor. A general overview of these analyses as well as test data documenting the contamination problem will be reviewed.

Application of a generalized diffraction analysis to the design of nonstandard Lyot-stop systems for earth limb viewing radiometers

“…[4][5][6][7][8] Here the wanted faint signal is typically a narrow-band IR thermal emission from trace gases in the atmosphere, and the unwanted bright off-axis source is the broadband thermally radiating earth, with the earth's horizon typically lying very close (Ͻ1 deg) to the edge of the field of view. In such cases, the diffraction and scatter lead to the earth producing an unwanted background signal on the radiometer detectors, and this is termed the nonrejected earth radiance 9 ͑NRER͒. This parameter is often the largest background, which limits the measurement accuracy, and so it is a major driver in instrument design.…”