Mitigation of Non-Narrowband Radio Frequency Interference Incorporating Array Imperfections

IF 1.5 Q3 ASTRONOMY & ASTROPHYSICS

Journal of Astronomical Instrumentation Pub Date : 2019-03-01 DOI:10.1142/S2251171719400130

Jan-Willem W. Steeb, D. Davidson, S. Wijnholds

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引用次数: 1

Abstract

In a recent paper, we presented a non-narrowband spatial radio frequency interference (RFI) mitigation algorithm for radio astronomy arrays. The algorithm constructs a 2nd-order filter by combining a 1st-order subspace subtraction method with a non-narrowband signal model. The model is based on the assumption that the frequency response is approximately flat and that the array is calibrated. In this paper, we consider the effects of array imperfections such as unknown complex gains and mutual coupling, incorporate these into the non-narrowband signal model and extend the RFI mitigation algorithm to include a calibration step. With a calibration step and no mutual coupling, the proposed algorithm was able to process twice the bandwidth per channel when compared to conventional narrowband techniques. This performance declines to 1.6 times greater bandwidth when the effect of mutual coupling is included. The evaluation of the algorithm was done using the layout of a Low Frequency Array (LOFAR) High Band Antenna (HBA) station and a digital audio broadcast recorded with a software defined radio.

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包含阵列缺陷的非窄带射频干扰的抑制

在最近的一篇论文中，我们提出了一种用于射电天文阵列的非窄带空间射频干扰(RFI)缓解算法。该算法将一阶子空间减法与非窄带信号模型相结合，构建二阶滤波器。该模型基于频率响应近似平坦且阵列经过校准的假设。在本文中，我们考虑了阵列缺陷的影响，如未知的复杂增益和相互耦合，将这些影响纳入到非窄带信号模型中，并扩展了RFI缓解算法以包括校准步骤。与传统窄带技术相比，该算法每通道处理的带宽是传统窄带技术的两倍。当包括相互耦合的影响时，该性能下降到1.6倍的带宽。利用低频阵列(LOFAR)高频段天线(HBA)站的布局和用软件定义无线电录制的数字音频广播，对该算法进行了评估。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Astronomical Instrumentation ASTRONOMY & ASTROPHYSICS-

CiteScore

2.30

自引率

7.70%

发文量

期刊介绍： The Journal of Astronomical Instrumentation (JAI) publishes papers describing instruments and components being proposed, developed, under construction and in use. JAI also publishes papers that describe facility operations, lessons learned in design, construction, and operation, algorithms and their implementations, and techniques, including calibration, that are fundamental elements of instrumentation. The journal focuses on astronomical instrumentation topics in all wavebands (Radio to Gamma-Ray) and includes the disciplines of Heliophysics, Space Weather, Lunar and Planetary Science, Exoplanet Exploration, and Astroparticle Observation (cosmic rays, cosmic neutrinos, etc.). Concepts, designs, components, algorithms, integrated systems, operations, data archiving techniques and lessons learned applicable but not limited to the following platforms are pertinent to this journal. Example topics are listed below each platform, and it is recognized that many of these topics are relevant to multiple platforms. Relevant platforms include: Ground-based observatories[...] Stratospheric aircraft[...] Balloons and suborbital rockets[...] Space-based observatories and systems[...] Landers and rovers, and other planetary-based instrument concepts[...]