Aperture division multispectral camera for the Earth's reflected solar radiation observation based on the Lagrange L1 point of the Earth-Moon system.

Abstract

We propose an aperture division multispectral camera for Earth observation (EAMC) based on the Lagrange L1 point of the Earth-Moon system to measure the Earth's reflected solar radiation (RSR), quantify the effective radiative forcing (ERF) and establish the pixel-scale multispectral angular distribution model (ADM) of the Earth's radiance. The EAMC adopts the snapshot technique to provide multispectral images in the 360-920 nm wavelength, employing nine subsystems sharing a primary system. The camera can capture the entire Earth's two-dimensional morphology and spectral fingerprints at a 10 km spatial resolution, with all spectral images acquired concurrently on a single detector. The camera's optical system is designed and simulated, and the stray light is analyzed and suppressed. Simulation and analysis results show that the camera can obtain high-quality images of the Earth's disk with a 2.5° field of view (FOV). The stray light is suppressed to less than 0.05% of the observed multispectral Earth radiation. The novel EAMC provides a new way to generate climate-relevant knowledge from the perspective of global Earth observation and has great potential for other applications in space-based remote sensing spectral imaging.