Measuring the Modulation Transfer Function (MTF) of a hyperspectral imaging spectrometer focused at infinity requires a longer optical path than is available in a typical laboratory. We describe a technique that uses images of rooflines on buildings of opportunity in a knife-edge-based MTF measurement. This technique only measures the MTF along one dimension. However, the hyper-spectral imaging systems characterized in this paper are particularly suited to a knife-edge technique, as imaging only takes place in one dimension of the array and spectral separation takes place along the other. The sharp edges needed in these measurements were provided by dark rooftops backlit by a uniformly cloudy sky. We have applied this technique to hyperspectral imagers that operate in the visible-near infrared (VNIR) and short-wave infraRed (SWIR) spectral bands. The data presented in this paper focuses on the characterization of the SWIR imaging spectrometer developed by Resonon Inc.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.