Coarse tracking of periscope-type satellite optical communication terminals

Many small aperture satellite optical communication terminals utilize a periscope as the Coarse Pointing Appliance(CPA), however, the model of coarse tracking arithmetic becomes much complex since the optic structure of the periscope-type CPA varies with the angle of attitude in the CPA . To improve the tracking accuracy of the CPA, this paper researches coarse tracking arithmetic of periscope-type satellite optical communication terminals. Based on the optical matrix method, a matrix model with geometric optics for tracking in the periscope-type inter-satellite optical communication terminals was established. After obtaining the CCD-based angle measuring model, an automatic tracking model of the CPA was derived to implement the fast tracking for the target beams. A test was performed to testify the arithmetic. The test results prove that the tracking arithmetic can express the configuration of optical system exactly, and can process the information of locality from CCD accurately. The average tracking accuracy is less than 10 μrad. The test results also show that the tracking model can meet the requirements of the satellite optical communication. The method proposed in this paper would supply some helps for similar optical study.