  A proof of concept for a frost detection imager using reflected starlight is
presented; the limitations of this technique are explored experimentally. An
ice-covered lunar surface is simulated inside a vacuum chamber, which is then
illuminated with a lamp containing UV and visible output to simulate the
wavelengths of the background starfield. The simulated lunar surface is imaged
with a camera utilizing a UV and visible filter pairing. At Lyman-alpha
wavelengths, ice has low reflectivity, and on average appears darker than the
regolith in the UV image. In visible wavelengths, this behaviour is reversed,
with ice appearing brighter than regolith. UV/VIS image ratioing is
subsequently performed in order to discern frost from the lunar regolith
simulant in order to demonstrate the capability of this technology for locating
the presence of ice on the lunar surface. When the two images are ratioed, the
signal to noise ratio to distinguish ice from regolith improves by 36%. In
cases where the presence of shadows and specular reflection make distinguishing
ice from regolith in either a single UV or visible image difficult, ratioing
the images makes the distinction clear.
