Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2012
Öğrenci: BURCU TUFAN
Danışman: TEMEL ENGİN TUNCER
Özet:In passive target localization, source position is estimated by only using the source signal. In this thesis, position of a stationary target is estimated by using the data collected by a moving platform. Since the focus of the thesis is the location estimation, the parameters used for localization such as angle-of-arrival (AOA), time-difference-of-arrival (TDOA), Doppler frequency shift are assumed to be known. Different emitter localization methods are implemented in this thesis. Some of these methods are known in the literature and some are the modified or hybrid versions of these algorithms. Orthogonal Vector Estimator (OVE), Pseudolinear Estimator (PLE), Weighted Instrumental Variables Estimator (WIVE) and Maximum Likelihood Estimator (MLE) use only the AOA information. In MLE, Gauss Newton (GN) search algorithm is used to realize the search process effectively. AOA localization methods are also implemented together with the extended Kalman filter (EKF) realization. Doppler Shifted Frequency (DSF) based Least Squares (LS) and MLE are implemented which use Doppler frequency shift only. AOA-DSF combined hybrid algorithm is shown to perform better. LS and Maximum Likelihood (ML) TDOA localization methods are also implemented. AOA-DSF-TDOA combined hybrid algorithm is shown to perform better than the algorithms which use one type of parameter and AOA-DSF hybrid algorithm. Estimator performances are analyzed in this thesis. Error ellipsoid is a useful tool to evaluate an estimator‟s performance. The parameters of the ellipsoids are drawn from Cramer-Rao Lower Bound (CRLB) matrices. The effect of target-sensor positioning is also investigated by using error ellipsoids. Several experiments are done where a platform is assumed to be moving on a pre-determined path while the target is stationary. The effects of different parameters are considered for the location estimation accuracy.