Adaptive servo control systems for Ka-Band data reception antennas
Adaptive Servo control System design is based on LQG controller, which is a Linear Quadratic Gaussian controller. It is an optimal and model based controller. Antenna Control servo system (ACSS) is used to control the motion of antenna. Present ACSS is based on PID (Proportional, Integral, Derivative) controller. This LQG controller overcomes the limitations of PID controller in terms of configurability of certain design parameters like rise time, settling time, Overshoot, servo error and disturbance rejection properties. Present PID based controller is not sufficient to meet the Ka and Ku band tracking requirements in view of its narrow beam width
FPGA implementation of CCSDS standard DWT-based image decompression
DWT based image compression technique is a compression standard used onboard satellites to improve transmission efficiency and for reducing storage requirements. This technique is very efficient to preserve the original image quality. On ground, the reverse process has to be done to retrieve the original data ie. DWT based decompression. This project work is VLSI Design of DWT based image decompression so that the design can be implemented in FPGA hardware. This hardware implementation will improve the ground data processing speed and hence the Turn around Time.
Development of high speed CCSDS image compression / decompression technique
The CCSDS has established a recommended standard for a data compression/ decompression algorithm applied to two-dimensional digital spatial image data from payload instruments and to specify how this compressed data shall be formatted into segments to enable decompression at the receiving end. The steps followed can be briefed as: performing an image de-correlating operation (DWT) and then encoding the coefficients in various stages in order to obtain the compressed image. The compressed image has to be decoded with the knowledge of the segment header. Rate regulation needs to be done in order to adjust the compression rate. The decoded coefficients are correlated back (inverse DWT) to get the reconstructed satellite image All the future Cartosat missions follow the CCSDS image compression/decompression technique and there is a need for the high speed implementation of the same. The requirement is the implementation of all the compression and decompression steps using General Purpose Graphics Processing Unit (GPGPU) and CUDA software.
