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Direction of arrival (DoA) estimation plays a crucial role in various areas of signal processing. Although existing methods perform satisfactorily at moderately high signal-to-noise ratio (SNR) levels of the order of 0 dB, they often lack accuracy in low SNR scenarios ([Formula: see text]10 dB), which is critical in science applications like radio frequency interference (RFI) mitigation for radio astronomy. In this context, it is essential to estimate the DoA of a source of RFI at low SNR to prevent high-gain radio telescope receivers from saturating. In this paper, a novel DoA estimation method is proposed, which is designed specifically for low SNR scenarios. This method involves multiple subarrays and decomposition techniques to enhance the SNR of the RFI. By comparing the signal subspace with the noise subspace, we can identify the potential incident direction and perform refinement in subsequent steps. Accuracy is further improved by combining all DoA candidates together and utilizing a clustering method to remove outliers. We conducted simulations using Automatic Dependent Surveillance-Broadcast (ADS-B) signals and sine waves in Additive White Gaussian Noise (AWGN) and multipath fading channels for signals that will be detected by a 100[Formula: see text]m radio telescope. The results demonstrate that our proposed method outperforms prior algorithms in low SNR conditions.
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This content will become publicly available on December 1, 2026
An Open-Source High-Level Graphical Signal Processing Language with Simulation and HDL Generation
The Collaboration for Astronomy Signal Processing and Electronic Research (CASPER) toolflow is a widely used framework for designing and implementing digital signal processing systems, particularly in the field of radio astronomy. It provides a set of tools and libraries that enable researchers to create custom hardware and software solutions for processing astronomical data. The CASPER toolflow has been instrumental in the development of Field-Programmable Gate Array (FPGA)-based digital instruments for various radio telescopes, enabling for real-time data processing and analysis. However, the current frontend tool that CASPER uses for high-level FPGA design is based on Model Composer integrated into MATLAB/Simulink, which is a proprietary software. In this paper, we introduce Scilab as a new frontend tool for the CASPER toolflow. Scilab is an open-source software platform for numerical computation and data visualization, which offers a similar environment to MATLAB/Simulink for designing CASPER blocks, generating FPGA Intellectual Property (IP) cores, and simulating Digital Signal Processing (DSP) systems. We present our implementation of Scilab in the CASPER toolflow and demonstrate its capabilities by developing an FPGA-based spectrometer on a RFSoC4[Formula: see text] × [Formula: see text]2, a commonly used CASPER platform well suited to radio astronomy applications. We have also developed Scilab support for other CASPER compatible platforms. Our results show that Scilab can successfully be used as an alternate frontend for CASPER-based designs.
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- Award ID(s):
- 2307781
- PAR ID:
- 10695682
- Publisher / Repository:
- World Scientific
- Date Published:
- Journal Name:
- Journal of Astronomical Instrumentation
- Volume:
- 14
- Issue:
- 03n04
- ISSN:
- 2251-1717
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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