Development of a Firmware for Designing and Implementation of Dual Axis Gimbal Optical Communication Satellite

Abstract

Optical communication is an emerging field in terms of satellite communication, ISRO is one of the space agency which is working towards the development of this technology for satellite communication. Apart from the conventional RF communi- cation systems earlier used for the satellite communication, Optical communication provides much more merits. High data rate, low mass power are one of the major driving forces for the usage of optical communication. Optical communication along with its merits, also follows up with its own share of challenges. To establish an accurate optical communication, many parameters are to be ensured in terms station acquisition, tracking pointing. Development of firmware for Designing and Implementation of Dual Axis Gimbal Optical Com- munication Satellite is one such part of Optical Communication Terminal (OCT) which takes care of the acquisition phase. Along with the Dual axis gimbal, image processing is also performed on the acquired data so as to identify the target to be tracked at the most accurate level. ATP makes the system complex by adding stringent tracking and pointing requirements. Image is acquired via a 5-megapixel raspberry pi camera, which is then processed for gray scale conversion and median filtering. Threshold operation is carried out on the acquired image for the better identification of the target. This image processing technique enhances the identification of the target and ensures a perfect link con- nection with the target. Once the acquisition of the target is done, tracking phase is commenced for the moving target. Tracking phase is a period in which move- ment of a target is mathematically calculated to obtain a delta value which will be processed further for the tracking phase. Tracking phase is a closed loop process once the target has been acquired. Tracking Phase compensates for the platform disturbances.