Design of an Offner convex grating radiation calibration light source with a wide dynamic range

In order to satisfy the spectral radiance calibration of remote sensing instruments in different spectral distribution, reduce the influence of spectral radiance calibration light sources on the calibration coefficients of space optical remote sensing instruments, and solve technical problems of low spectral simulation accuracy and small spectral dynamic adjustment range, a design method for Offner type convex grating radiation calibration systems with a wide dynamic range based on spectral superposition and the principles of multi-spectral synthesis was presented, and its anastigmatic conditions were derived. The Offner spectral imaging optical system was designed with a cylindrical mirror with an accurate subdivision of broad spectral beams. Then, the mapping relationship between the array surface of the Digital Micro-mirror Device (DMD) and its spatial spectral radiation distribution was designed. The large dynamic range simulation of spectral distribution with the spatial light modulation characteristics of the DMD was achieved. Experiment results show that the interval of the spectral peak has an output by the adjacent unit array micro-mirror is greater than 0.5 nm, the spectral simulation accuracy of three typical color temperatures is 5.2% at T=3000 K, 4.1% at T=5000 K, and 3.2% at T=7000 K. The spectral simulation accuracy of the radiation calibration source was significantly improved, and the influence of spectral mismatch on the calibration coefficients of space optical remote sensing instruments was effectively diminished.