This paper discusses an innovation in reflectometry that presents cost and implementation advantages over configurations currently in use. We demonstrate that the semi-continuous wavelength spectrum used by a spectroscopic reflectometer can be replaced with a small set of fixed wavelength optical sources with only a small loss in measurement accuracy. The resulting instrumentation is called a spectrum sampling reflectometer (SSR). Spectrum sampling can be achieved using inexpensive LEDs and/or lasers as the optical sources. Theoretical calculations for instrument accuracy are shown for both LEDs and lasers along with experimental data from a prototype system using LEDs.