Real-time RFI Excision Techniques and their Limitations

TL;DR

This paper reviews current real-time RFI mitigation techniques in radio telescopes, discussing their implementation, limitations, and the impact of advanced signal processing platforms like FPGA and GPU.

Contribution

It provides a comprehensive overview of contemporary RFI excision methods and analyzes their limitations in real-time radio telescope signal processing.

Findings

High-speed platforms enable advanced RFI mitigation algorithms.

RFI is typically stronger and non-Gaussian, affecting signal quality.

Implementation challenges limit the effectiveness of current techniques.

Abstract

Contemporary real-time RFI mitigation is carried out at different stages primarily using regulatory and technical approaches. Regulatory approaches include spectrum management, radio quiet zones, and ensuring protection from self-generated RFI. The technical approaches include mitigation RFI in the analog and RF frontend systems, digital signal processing systems, and offline systems. As is known, the signal received by a radio telescope is a combination of the contributions from the astronomical signal and a combination of system and sky background noise. RFI has an additive effect on the signal received by the radio telescope. The key distinguishing properties of RFI are that it is generally stronger than the signal and non-Gaussian. The capability of signal processing receiver systems has grown manifold with the advent of high-speed signal processing platforms like Field Programmable Gate Arrays (FPGA)and Graphics Processing Unit (GPU). This has enabled the development of different signal-processing techniques for real-time RFI mitigation algorithms. This document provides an overview of contemporary techniques while focusing on the implementation of the same in specific radio telescopes.