Electronic System Design For AOTF Polarizing Hyperspectral Imager

Polarization hyperspectral imaging technology is a new optical information acquisition technology currently emerging.How to effectively acquire,process,analyze,and utilize polarization hyperspectral image information,become a research focus.Moreover,in applications such as deep space exploration,land exploration,and atmospheric exploration,the polarization hyperspectral imager is required to be compact,robust,flexible and autonomous.According to such requirements,a new type of polarization hyperspectral imaging is proposed that can rapidly electrically tune the AOTF in the spectral segment as a spectral dispersion element,obtain multiple linear polarization images simultaneously in an aperture division manner,and can both stare-in imaging and push-scan imaging technology.Based on this technical scheme,this paper comprehensively considers the system requirements and selects EMCCD as the detector and FPGA as the control core to build the image acquisition system.Before setting up the system,first understand the working principle and driving mode of EMCCD,and study the use of analog-todigital converters,as well as the method of temperature telemetry.The construction system includes two parts,hardware design and embedded software design.For the imaging system requirements,various functional modules are designed in the hardware part,including the following: Image acquisition module composed of CCD 97-00 detector and AD9826 analog-to-digital converter.The temperature telemetry and cooling control module is composed of thermistors,analog-digital and digital-to-analog converters,and semiconductor cooler;A serial transmission and conversion chip TLK1501 and an optical fiber interface chip AFBR-5717 are used to constitute the optical fiber transmission module.The embedded software design is written with VHDL.Around the design of hardware,functions such as driving of each chip,image data acquisition and transmission,state telemetry and real-time control of focal plane circuit.Afterwards,the commissioning of the electronic system was completed,the image and telemetry information were successfully acquired,and the camera could be controlled in real time from the host computer.This system can be combined with the optical system to perform calibration experiments,image registration,and the like,laying a good foundation for the development of the polarization hyperspectral imager.