MUSIC based multi target bearing estimation for DIFAR sonobuoys using adaptive prewhitening and forward backward covariance averaging

Yeonjin Park; Jungpyo Hong

doi:10.7776/ASK.2026.45.4.400

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2026 Vol.45, Issue 4 Preview Page Next Page

MUSIC based multi target bearing estimation for DIFAR sonobuoys using adaptive prewhitening and forward backward covariance averaging 적응형 사전백색화와 전후방 공분산 평균을 이용한 DIFAR 소노부이의 MUSIC 기반 다중 표적 방위각 추정

31 July 2026. pp. 400-417

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Abstract

A Directional Frequency Analysis and Recording (DIFAR) sonobuoy estimates horizontal bearing using an omnidirectional pressure sensor and two orthogonal particle velocity sensors. Owing to the limited number of observation channels, however, spectral peaks associated with multiple targets may merge when two or more targets are present, making it difficult to resolve individual Directions Of Arrival (DOAs). To alleviate this limitation, this paper proposes a Multiple Signal Classification (MUSIC) based multi target DOA estimation method for DIFAR sonobuoys. The proposed method transforms the DIFAR measurements into an equivalent three element Virtual Linear Array (VLA) response and applies forward backward covariance averaging and adaptive prewhitening prior to MUSIC spectrum estimation. In the VLA domain, the method reduces the effect of covariance-structure degradation caused by coherent signals and normalizes channel power differences using the diagonal components of the covariance matrix. The proposed method was evaluated under coherent two target conditions in a narrowband simulated DIFAR environment and compared with Conventional Beamforming (CBF), Capon, MUSIC, and Greedy Capon Beamformer (GCB). The results show that the proposed method achieved an average two peak detection rate of 85.55 %, outperforming the comparison methods. For successfully detected cases, the Root Mean Square Error (RMSE) decreased with increasing Signal to Noise Ratio (SNR) and reached 4.88° at 10 dB.

Keywords

Directional Frequency Analysis and Recording (DIFAR) sonobuoy

Directions Of Arrival (DOA) estimation

Multiple Signal Classification (MUSIC)

Multi target separation

Adaptive prewhitening

Forward backward covariance averaging

Directional Frequency Analysis and Recording(DIFAR) 소노부이는 하나의 무지향성 압력 센서와 두 개의 직교 입자속도 센서를 이용하여 단일 부이에서 수평면 방위각을 추정할 수 있다. 그러나 관측 채널 수가 세 개로 제한되기 때문에, 두 개 이상의 표적이 동시에 존재하는 경우 각 표적에 대응하는 스펙트럼 피크가 병합되어 개별 도래각(Directions Of Arrival, DOA)을 구분하기 어렵다. 본 논문에서는 이러한 한계를 완화하기 위해 DIFAR 신호를 3소자 가상 선형 배열(Virtual Linear Array, VLA) 응답으로 변환하고, 전후방 공분산 평균과 적응형 사전백색화를 결합한 Multiple Signal Classification(MUSIC) 기반 다중 표적 도래각 추정 기법을 제안한다. 제안 기법은 가상 선형 배열 영역에서 코히어런트 신호에 의한 공분산 구조의 영향을 완화하고, 공분산 행렬의 대각 성분을 이용하여 채널 전력 차이를 정규화한 뒤 MUSIC 스펙트럼을 계산한다. 협대역 모의 DIFAR 환경에서 코히어런트 두 표적 조건을 대상으로 Conventional Beamforming(CBF), Capon, MUSIC, Greedy Capon Beamformer(GCB) 방식과 성능을 비교하였다. 제안 기법은 평균 두 피크 검출률 85.55 %를 보였으며, 이는 비교 기법들보다 높은 검출률이다. 또한 두 피크 검출에 성공한 경우의 추정 오차(Root Mean Square Error, RMSE)는 신호대잡음비(Signal to Noise Ratio, SNR)이 증가함에 따라 감소하였고, 10 dB 조건에서 4.88°로 나타났다.

키워드

Directional Frequency Analysis and Recording (DIFAR) 소노부이

도래각(Directions Of Arrival, DOA) 추정

Multiple Signal Classification (MUSIC)

다중 표적 분리

적응형 사전백색화

전후방 공분산 평균

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Information

Publisher :The Acoustical Society of Korea
Publisher(Ko) :한국음향학회
Journal Title :The Journal of the Acoustical Society of Korea
Journal Title(Ko) :한국음향학회지
Volume : 45
No :4
Pages :400-417
Received Date : 2026-06-08
Revised Date : 2026-07-08
Accepted Date : 2026-07-08
DOI :https://doi.org/10.7776/ASK.2026.45.4.400

The Journal of the Acoustical Society of KoreaISSN:1225-4428(Print) 2287-3775(Online)한국음향학회

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