On-orbit calibration of MWIR-data for rocket detection with a 12U CubeSat

Launched in August 2024, the experimental nanosatellite ERNST, weighing 18kg at a 12U CubeSat format, aims to demonstrate the capabilities of small, cost-effective satellites in the field of missile tracking using a cryogenically cooled infrared camera combined with a powerful onboard data processing system. The camera features a commercial infrared lens with a 100mm focal length and an AIM HiPIR-1280M sensor chip with 1280×1024 px resolution, yielding a theoretical ground sampling distance of 75m from an orbital height of 500km. The sensor operates at 114K, cooled by a linear Stirling cooler. This paper details our initial efforts for on-orbit calibration of the camera system, including the creation of calibration frames for the mid-wave infrared filter and for various exposure times. We tested several calibration targets for flat frames and observed open space for dark frames. The relevant procedures are coded in Lua and the calibration frames are updated regularly to ensure their optimal performance.