Design of spaceborne full-spectrum hyperspectral system

Due to spacecraft’s volume and weight constraints, it is challenging to simultaneously obtain large aperture, high resolution, and hyperspectral information in spaceborne remote sensing systems. We propose a novel hyperspectral imaging system that utilizes a shared primary and secondary mirror design and a coaxial five-mirror optical path for multi-channel separation. By integrating Offner convex grating spectroscopy, the system enables hyperspectral detection from the visible to the long-wave infrared spectrum. Design results indicate that with a primary mirror diameter of 1000 mm at an altitude of 500 km, the spatial resolution in the visible and short-wave bands exceeds 2 m, in the mid-wave band exceeds 3 m, in the long-wave band exceeds 6 m, and the panchromatic resolution is better than 1 m. The system achieves a full field of view of 2.3°, accommodating a swath width of 20 km for detection. To enhance the system's aberration and distortion correction capabilities, high-order aspheric elements are incorporated to create a telecentric optical path, ensuring optimal matching between the telescope and the spectrometer. Furthermore, we propose housing the spectrometer module in a cooling chamber to effectively mitigate the impact of background radiation from the optical structure on image quality. The final design demonstrates excellent imaging quality, a simple layout, and a compact structure, enabling the simultaneous acquisition of high spectral information across the entire spectrum. This system has broad applications in satellite-based earth observation and imaging.