We describe the use of LIDAR, or "laser radar," (LR) as a fast, accurate, and non-contact tool for the
measurement of the radius of curvature (RoC) of large mirrors. We report the results of a demonstration of
this concept using a commercial laser radar system. We measured the RoC of a 1.4m x 1m spherical mirror
with a nominal RoC of 4.6m with a manufacturing tolerance of 4600mm +/- 6mm. The prescription of the
mirror is related to its role as ground support equipment used in the test of part of the James Webb Space
Telescope (JWST). The RoC of such a large mirror is not easily measured without contacting the surface.
From a position near the center of curvature of the mirror, the LIDAR scanned the mirror surface, sampling it
with 1 point per 3.5 cm2. The measurement consisted of 3983 points and lasted only a few minutes. The laser
radar uses the LIDAR signal to provide range, and encoder information from angular azimuth and elevation
rotation stages provide the spherical coordinates of a given point. A best-fit to a sphere of the measured points
was performed. The resulting RoC was within 20 ppm of the nominal RoC, also showing good agreement
with the results of a laser tracker-based, contact metrology. This paper also discusses parameters such as test
alignment, scan density, and optical surface type, as well as future possible application for full prescription
characterization of aspherical mirrors, including radius, conic, off-axis distance, and aperture.