Development and testing of a multi-spectral and multi-field of view imaging system for space-based signature detection and tracking of hypersonic vehicles

Abstract

Hypersonic glide vehicles can glide several thousand kilometers through the Earth's atmosphere at hypersonic Mach numbers. Their inherent characteristics make them difficult to detect by both ground-based and spacebased sensors. The Universität der Bundeswehr München aims to demonstrate the capability of the Multispectral Object Sensing by Artificial Intelligence-processed Cameras (MOSAIC) experiment to detect and track radiation signatures of hypersonic glide vehicles from Low Earth Orbit on-board the small-satellite ATHENE-1. The payload consists of a cryo-cooled mid-wave infrared sensor with a pixel count of more than 1 M P x. The use of variable optics increases flexibility with regards to spatial and spectral resolution. Spectral filter selection is based on atmospheric simulations. A 25 M P x color imager sensitive in the visible spectrum is implemented together with a fixed focal length lens for complementary cross validation of detection by postprocessing onground. Both imagers are processed on-board the satellite by a high-performance computer that accelerates artificial intelligence image processing methods. All components used are commercial-off-the-shelf components that are tested and modified for their application in space at the Universität der Bundeswehr München. Two test set-ups are developed to characterize the modulation transfer function of the optical systems. Besides an ISO 12233 approach in the visible spectrum, an infinite-conjugate back-illuminated set-up is implemented for the infrared system. This study outlines design drivers and their specific solution approaches for an early warning system for a small-satellite application. A brief analysis of the radiometric budget forms the basis for a further preliminary design. Finally, test set-ups for performance validation are outlined.