A unique broadband scatterometer has been designed, built and tested for NASA Goddard. One use of the instrument will be to accurately measure the BRDF of calibration standards used by shuttle astronauts in experiments to measure atmospheric ozone. BRDF accuracy is better than 1% except for angles of incidence and scatter greater than 80 degrees. The source employs a high intensity xenon arc and programmable monochromator that allows measurements to be made anywhere from 0.23 to 0.9 micrometers over adjustable bandwidths as small as four nanometers. The goniometer allows out-of-plane measurements to be made in either transmission or reflection from horizontal samples.