Statistical Analysis of Speckle Noise Reduction in C-Band SAR Image Using FFT Based Circular Pass Filter And Circular Cut Filter

Abstract

Image Enhancement plays a vital role in image processing applications and is an active field of research. In remote sensing, various imaging modalities, i.e., optical, infrared, and microwave satellite sensors, are used to get information about the earth's surface and objects. In Microwave remote sensing, coherent sources are used for imaging purposes. Due to coherent sources, speckle noise gets added to an image during acquisition. It causes loss of information and blurring, which leads to loss of the information of the objects. For eliminating speckle noise, various despeckling filters are used, and their performance is analyzed based on objective assessment parameters. In this paper, the FFT-based frequency domain Circular Pass Filter and Circular Cut Filtering techniques are applied to remove speckle noise from SLC level-1 SAR data. The methods are applied to C- band SAR Sentinel-1A data. The simulated results were analyzed based on performance evaluation parameters as ENL, standard deviation, and coefficient of variance.