Spectral Measurements of Geosynchronous Satellites during Glint Season

During certain times of the year, stable geosynchronous (GEO) satellites are known to glint or exhibit a very bright specular reflection, which is easily observed through broadband photometric filters. The glints are typically brighter in the Johnson red filter compared to the Johnson blue filter.~ In previous years, USAFA cadets have developed and refined techniques to take, calibrate and process satellite spectral data using a diffraction grating on the USAFA 16-inch, f/8.2 telescope (i.e. slitless spectroscopy). We present research from an Air Force Academy senior physics capstone project on observing glints off of GEO satellites using slitless spectroscopy. We discuss the calibration of the measurements using solar analog stars, as well as results of the spectra of a glinting GEO satellite.