OPTICAL-PROPERTIES OF ORBITAL DEBRIS

This paper discusses the albedos and phase angle effects found for 400 members of seven debris swarms using observations obtained in 1990 an d 1991 with the NASA Johnson Space Center charge couple device-equippe d portable Schmidt telescope. The mean albedo derived by comparing opt ical brightnesses with average radar cross sections (RCSs) is 10%. The standard deviation in log albedo is 0.35 if the RCSs are assumed to c ontribute equally to the scatter. Forty objects are sufficiently free of tumble or aspect angle effects to yield consistent phase function s lopes. These range from specular in nature (zero slope) through lamber tian (moderate slope) to lunar (steep slope) with the mean lying midwa y between specular and lambertian. Swarm-to-swarm comparison shows the Cosmos 1375 debris to have unusually small scatter in albedo and the Spot 1/Viking debris to have unusually bright albedos.