Sun-induced veiling glare in dusty camera optics

The National Aeronautical and Space Administration (NASA) is planning to send two Mars Exploration Rovers (MER) to Mars in 2003. Onboard these rovers will be a number of scientific and engineering cameras. Mars is a dusty place, so dust will accumulate on the front surface of the camera optics. When the sun shines on the dusty front surface, light will be scattered to the detector. This increases glare and reduces contrast. The rover lenses must work, even when the sun shines on the front element. Therefore, the veiling glare has been evaluated by experiments. We discuss these experiments and the results. (C) 2004 Society of Photo-Optical Instrumentation Engineers.