A method of in-situ wavefront measurement of an electro-optic sensor during test and calibration of the EO sensor in the production line, comprising: mounting the EO sensor in a test fixture, said EO sensor including an optical telescope having an entrance pupil for receiving an electro-magnetic wavefront and focusing the wavefront to an image plane, an EO detector positioned near the image plane to convert an image of a scene to an electronic representation, a video card that reads out a temporal sequence of frames from the electronic representation to produce a video signal at an output port, and an opto-mechanical mount that mounts the EO detector to the telescope; tracing a single sub-pupil sized optical beam, in a spatial pattern over the entrance pupil to serially illuminate a temporal sequence of sub-pupils, said EO sensor's optical telescope focusing the beam into an image on the EO detector, said EO detector and video card capturing a video signal of the image for one sub-pupil at a time as the beam traces the spatial pattern; routing the video signal from the output port to a computer processor; and with said computer processor computing a spatio-temporal mapping of the positions of the sub-pupils in the spatial pattern to the temporal positions of frames in the video signal and using the mapping to compute a wavefront estimate spanning the entrance pupil; wherein the sub-pupil optical beam is traced in the spatial pattern by: emitting a divergent beam from a blackbody source; passing the divergent beam through a collimating telescope that produces a source collimated beam, that spans the entrance pupil; providing a first disk, said disk formed with a plurality of holes of the sub-pupil size arranged in the spatial pattern; providing a second disk, said disk formed with a plurality of holes of the sub-pupil size arranged in a complementary spatial pattern; and rotating the second disk relative to the first disk so that only one hole in the second disk is aligned to only one hole in the first disk at a time and illuminated by the source collimated beam to trace the single sub-pupil, optical beam in the spatial pattern. mounting the EO sensor in a test fixture, said EO sensor including an optical telescope having an entrance pupil for receiving an electro-magnetic wavefront and focusing the wavefront to an image plane, an EO detector positioned near the image plane to convert an image of a scene to an electronic representation, a video card that reads out a temporal sequence of frames from the electronic representation to produce a video signal at an output port, and an opto-mechanical mount that mounts the EO detector to the telescope; tracing a single sub-pupil sized optical beam, in a spatial pattern over the entrance pupil to serially illuminate a temporal sequence of sub-pupils, said EO sensor's optical telescope focusing the beam into an image on the EO detector, said EO detector and video card capturing a video signal of the image for one sub-pupil at a time as the beam traces the spatial pattern; routing the video signal from the output port to a computer processor; and with said computer processor computing a spatio-temporal mapping of the positions of the sub-pupils in the spatial pattern to the temporal positions of frames in the video signal and using the mapping to compute a wavefront estimate spanning the entrance pupil; wherein the sub-pupil optical beam is traced in the spatial pattern by: emitting a divergent beam from a blackbody source; passing the divergent beam through a collimating telescope that produces a source collimated beam, that spans the entrance pupil; providing a first disk, said disk formed with a plurality of holes of the sub-pupil size arranged in the spatial pattern; providing a second disk, said disk formed with a plurality of holes of the sub-pupil size arranged in a complementary spatial pattern; and rotating the second disk relative to the first disk so that only one hole in the second disk is aligned to only one hole in the first disk at a time and illuminated by the source collimated beam to trace the single sub-pupil, optical beam in the spatial pattern. emitting a divergent beam from a blackbody source; passing the divergent beam through a collimating telescope that produces a source collimated beam, that spans the entrance pupil; providing a first disk, said disk formed with a plurality of holes of the sub-pupil size arranged in the spatial pattern; providing a second disk, said disk formed with a plurality of holes of the sub-pupil size arranged in a complementary spatial pattern; and rotating the second disk relative to the first disk so that only one hole in the second disk is aligned to only one hole in the first disk at a time and illuminated by the source collimated beam to trace the single sub-pupil, optical beam in the spatial pattern.