Fundamental to the performance of an active infrared imager, is the Bi-directional Reflectance Distribution Function (BRDF) from potential target and surveillance surfaces. Proper integration of the BRDF also can yield emissivity, a quantity that is important to determine emitted infrared radiance for passive sensors, especially in sunlit conditions in the SWIR and MWIR. A series of BRDF measurements were acquired in up to four bandpasses ranging from 3 to over 11 microns. Results are presented for multiple surfaces in these bandpasses with the incidence angles of the radiation at -45 degrees in elevation, and azimuth angles from 0 to 180. Materials measured included likely target and background materials such as: human skin, clothing materials, wood, paper, water, sand and crude oil.