Design of PWM-based spectrum tunable light source

Starlight navigation is a navigation technology with strong anti-interference ability, which can output aircraft attitude, azimuth and other information. The star sensors not only have the highest measurement accuracy, but also have no time drift error, so that they become the most widely used attitude sensors in the aerospace field. The star sensor shall be calibrated before being put into use to ensure the accuracy of the star sensor. When the star simulator is used to calibrate the magnitude of the star sensor, the mismatch between the spectrum of the star simulator and the simulated star spectrum will produce a large magnitude simulation error. Therefore, a spectral tunable light source based on pulse width modulation is studied and designed in this paper, which can simulate the stellar radiation at different color temperatures, in order to solve the high-precision magnitude calibration of star sensor under different color temperatures. The spectrum tunable light source based on PWM control can realize 3000K ~ 20000k spectrum modulation within 360 ~ 900nm, the output optical power is stable, the error of spectrum simulation is better than ±0.1, and the uniformity of light source is better than 97%. It can be used for high-precision radiation calibration of star sensor with different color temperature. The problem of spectrum mismatch between star sensor and star simulator is solved, and the error of magnitude simulation is reduced.