Efficient Localization of Directional Emitters via Joint Beampattern Estimation

Fuente: arXiv
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Main Authors: Williams, Fraser, Pemasiri, Akila, Jayalath, Dhammika, Martin, Terry, Fookes, Clinton
Format: Preprint
Published: 2024
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author Williams, Fraser
Pemasiri, Akila
Jayalath, Dhammika
Martin, Terry
Fookes, Clinton
author_facet Williams, Fraser
Pemasiri, Akila
Jayalath, Dhammika
Martin, Terry
Fookes, Clinton
contents The localization of directional RF emitters presents significant challenges for electronic warfare applications. Traditional localization methods, designed for omnidirectional emitters, experience degraded performance when applied to directional sources due to pronounced received signal strength (RSS) modulations introduced by directive beampatterns. This paper presents a robust direct position determination (DPD) approach that jointly estimates emitter position and beampattern parameters by incorporating RSS modulation from both path attenuation and directional gain alongside angle of arrival (AOA) and time difference of arrival (TDOA) information. To address the computational challenge of joint optimization over position and beampattern parameters, we develop an alternating maximization algorithm that decomposes the four-dimensional search into efficient iterative two-dimensional optimizations using a generalized beampattern model. Cramer-Rao Lower Bound (CRLB) analysis establishes theoretical performance limits, and numerical simulations demonstrate substantial improvements over conventional methods. At -10 dB SNR, the proposed approach achieves 49% to 61% error reduction compared to AOA-TDOA baselines, with performance approaching the CRLB above -10 dB. The algorithm converges rapidly, requiring 3 to 4 iterations on average, and exhibits robustness to beampattern model mismatch. A contrast-expanded half-power uncertainty metric is introduced to quantify localization confidence, revealing that the proposed method produces concentrated unimodal likelihood surfaces while conventional approaches generate spurious peaks. Sensitivity analysis demonstrates that optimal performance occurs when receivers are positioned at beampattern main lobe edges where RSS gradients are maximized.
format Preprint
id arxiv_https___arxiv_org_abs_2411_04364
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Efficient Localization of Directional Emitters via Joint Beampattern Estimation
Williams, Fraser
Pemasiri, Akila
Jayalath, Dhammika
Martin, Terry
Fookes, Clinton
Signal Processing
The localization of directional RF emitters presents significant challenges for electronic warfare applications. Traditional localization methods, designed for omnidirectional emitters, experience degraded performance when applied to directional sources due to pronounced received signal strength (RSS) modulations introduced by directive beampatterns. This paper presents a robust direct position determination (DPD) approach that jointly estimates emitter position and beampattern parameters by incorporating RSS modulation from both path attenuation and directional gain alongside angle of arrival (AOA) and time difference of arrival (TDOA) information. To address the computational challenge of joint optimization over position and beampattern parameters, we develop an alternating maximization algorithm that decomposes the four-dimensional search into efficient iterative two-dimensional optimizations using a generalized beampattern model. Cramer-Rao Lower Bound (CRLB) analysis establishes theoretical performance limits, and numerical simulations demonstrate substantial improvements over conventional methods. At -10 dB SNR, the proposed approach achieves 49% to 61% error reduction compared to AOA-TDOA baselines, with performance approaching the CRLB above -10 dB. The algorithm converges rapidly, requiring 3 to 4 iterations on average, and exhibits robustness to beampattern model mismatch. A contrast-expanded half-power uncertainty metric is introduced to quantify localization confidence, revealing that the proposed method produces concentrated unimodal likelihood surfaces while conventional approaches generate spurious peaks. Sensitivity analysis demonstrates that optimal performance occurs when receivers are positioned at beampattern main lobe edges where RSS gradients are maximized.
title Efficient Localization of Directional Emitters via Joint Beampattern Estimation
topic Signal Processing
url https://arxiv.org/abs/2411.04364