Bias compensation for least-squares multi-pulse TDOA localization algorithms

© Copyright 2005 IEEEA weighted least squares (WLS) estimator is presented for time difference of arrival (TDOA) localization of an emitter using multiple TDOA measurements collected by moving receivers. A comprehensive bias analysis for this estimate is provided. Based on the outcomes of the bias analysis, a bias compensation algorithm is developed to reduce the severe WLS estimation bias. The proposed algorithm utilizes an estimate of the instantaneous bias derived from the WLS estimate itself. The significant bias reduction capability of the proposed bias compensation algorithm is illustrated with simulation examples involving geolocation of a pulse radar by unmanned aerial vehicles (UAVs).Dogancay, K. Gray, D.A

Some applications of tensor algebra to estimation theory

Tensor algebra and tensor calculus are widely used in the the fields of mathematics and physics but their usefulness in estimation theory has not been widely appreciated. In this paper we give a short introduction to tensor algebra and provide a few examples of how to use it. None of the results presented in this paper are original but they are novel in showing how tensor algebra can be used to derive results that take much longer and are more cumbersome using a traditional linear algebra approach.Samuel Picton Drake, Kutluyil Doğança

Closed-form estimators for multi-pulse TDOA localization

© Copyright 2005 IEEEMost time difference of arrival (TDOA) localization algorithms process only one set of TDOA measurements to compute the emitter location. In certain applications such as pulse radar localization we are presented with a large number of TDOA measurements over very short time intervals. The paper develops new closed-form multi-pulse localization algorithms that exploit additional information available from multiple TDOA measurements. Reduced bias estimators are also developed. The superior bias performance of the new algorithms is demonstrated by way of computer simulations. © 2005 IEEE.Dogancay, K. Gray, D.A

Least Squares Approach to Blind Channel Equalization

We present a least squares (LS) algorithm for blind channel equalization based on a reformulation of the Godard algorithm. A transformation for the equalizer parameters is considered to convert the nonlinear LS problem inherent in the Godard algorithm t

Centralized path planning for unmanned aerial vehicles with a heterogeneous mix of sensors

This paper is concerned with real-time optimal UAV path planning in a multi-emitter geolocation environment. All UAVs are assumed to be controlled by a central processing unit. A UAV waypoint-update/steering algorithm is developed based on maximizing the determinant of Fisher information matrix for localization of stationary emitters. Soft and hard geometric constraints for threat/collision avoidance are also implemented. An effective joint path optimization and dynamic sensor allocation algorithm is proposed to handle communication bandwidth constraints. The performance of the developed steering algorithm is illustrated with extensive simulation examples.Kutluyıl Doğançay, Hatem Hmam, Samuel P. Drake, Anthony Fin

Waveform Selection for a Scanning Radar in the Maritime Environment

Detection of slow moving targets for a scanning radar in the maritime domain is typically performed using noncoherent detectors with both pulse-to-pulse and/or scan-to-scan integration. Other processing options include coherent processing for slowly scanning radars and pulse-to-pulse frequency agility which decorrelates the clutter, but restricts the processing to non-coherent. This paper studies the impact of these processing options when operating in different environments and proposes a guide for selecting the waveform that optimises the detection performance.Azam Mehboob, Luke Rosenbergy, Kutluyil Dogancay, Brian Ng and Mike Harta