Design of acousto-optic imaging spectrometer for mars exploration

For mars exploration, a novel prototype of imaging spectrometer consisting of an optomechanical subsystem and an electronic subsystem was designed based on an Acousto-optic Tunable Filter(AOTF). An achromatic telescopic optical system was used in the spectrometer and its spectral range was between 550 nm and 1000 nm, while the spectral resolution was 0.9-4 nm. In electronic subsystem, a system-on-a-programmable-chip was introduced and data transmission was implemented by employing a novel bus technology of SpaceWire. On the basis of laboratory calibration, the prototype was installed in the stimulant mars explorer, and a hyperspectral imaging experiment was performed. Experimental results indicate that the prototype of imaging spectrometer can offer good imaging quality and the measurement identify between the prototype and an ASD spectrometer is over 96%. Furthermore, the SpaceWire bus can transport data at a rate of 100 Mbps continuously, which satisfies the technique requirement of 25 Mbps. The development of the prototype provides technical foundation for applications of AOTF imaging spectral technique to mars-based remote sensing in future.