Abstract: A method for spatial calibration of an infrared (IR) camera allows for a large calibration area thereby providing high fidelity results for accurate long-distance measurement. Halogen lamps capable of being surveyed are spread over a relatively wide area to serve as calibration points for the infrared camera. The halogen lamps provide a precise and symmetric signature suitable for mid-wave IR cameras. An accurate model is developed for the radial and tangential distortion of the camera system. Likewise, values for the intrinsic parameters (focal lengths and optional skew coefficient) are measured to improve real-world measurements made using images recorded from a calibrated camera system.