Research On The Heliograph Image Reconstruction

The radio heliograph is a synthesis aperture system with a large-scale antenna arrayused to image the radio sun. The ultimate goal of this system is to obtain the ideal solarintensity distribution image. The contradiction between the limited budget and theantenna number is the main factor in restricting the performance of the system. One ofthe important goals of the research on the heliograph is how to get optimalreconstruction image from the established and fewer sampling points within budget.Focusing on the heliograph image reconstruction, this paper made deep discussionand did research on the application of compressed sensing in the heliograph imagereconstruction and Richardson–Lucy algorithm with total variation regularization.The main work of this paper is as follows.1. The topology structure of four kindsof regular antenna array was simulated and their imaging performance was analyzed.2. The compressed sensing theory was first successful applied to heliograph imagereconstruction, and a new image reconstruction algorithm was proposed under theframework of the compressed sensing. Compare with other algorithm, the simulation ofY and three-arm screw array shows that the new method is better in terms of theresolution of the adjacent points, the shape of the extended source and the dynamicrange.3. A new RL algorithm with total variation regularization was proposed based onsome projection on a closed convex set in Hilbert space, and it was successfully used toreconstruct the heliograph image. The simulation under two arrays shows that thealgorithm is able to obtain more accurate reconstruction image compared with standardRL algorithm with total variation with the same samples.