We introduce a new ambiguity function for general parameter estimation problems in curved exponential families. We focus the presentation on passive and active radar and sonar location mechanisms. The new definition is based on the Kullback directed divergence and reflects intrinsic properties of the model. It is independent of any specific algorithms used in the processing of the signals. For ...

This tutorial describes the basis of passive bistatic radar (PBR) systems, and in particular the nature of the waveforms of illuminators of opportunity that they exploit. It shows that there is a wide variety of such waveforms, from broadcast, communications and radionavigation transmissions, and that in general they are not optimum for radar purposes. In addition, they usually vary significant...

I study a dynamic principal agent model in which the effort cost of the agent is unknown to the principal. The principal is ambiguity averse, and designs a contract which is robust to the worst case effort cost process. Ambiguity divides the contract into two regions. After sufficiently high performance, the agent reaches the over-compensation region, where he receives excessive benefits compar...

Under wide sense stationary uncorrelated scattering (WSSUS) conditions, the signal spreading due to a random channel may be described by the scattering function (SF). In an active acoustic system, the received signal is modeled as the superposition of delayed and Doppler spread replicas of the transmitted waveform. The SF completely describes the second-order statistics of a WSSUS channel and c...

We discuss range and Doppler processing for FMCW radar using only a single pulse or frequency sweep. The first step is correlation processing, for which the range and Doppler resolution are limited by the ambiguity function. We show that this resolution can be optimized with an additional inverse filtering step. The method is demonstrated for sinusoidal FMCW radar measurements. Several regulari...

In this article we consider the approximate description of doubly–dispersive channels by its symbol. We focus on channel operators with compactly supported spreading, which are widely used to represent fast fading multipath communication channels. The concept of approximate eigenstructure is introduced, which measures the accuracy Ep of the approximation of the channel operation as a pure multi...

The start-stop approximation is a standard tool for processing radar data in synthetic aperture imaging. It assumes that the antenna is motionless when a pulse is emitted and the scattered signal received, after which the antenna moves to its next sending/receiving position along the flight track. However, when the antenna is mounted on a satellite, as opposed to an airplane, its relatively hig...

Defeasible reasoning is a simple but efficient rule-based approach to nonmonotonic reasoning. It haspowerful implementations and shows promise to be applied in the areas of legal reasoning and themodeling of business rules. This paper establishes significant links between defeasible reasoning andargumentation. In particular, Dung-like argumentation semantics is provided for two key ...

The invention is a method for improved active sonar using a singular value decomposition filtering and a Volterra-Hermite Basis Expansion to model real active sonar measurements. The fitting model minimizes the sum of the squared errors between a measured channel response, z(t), and model response, y(t), which is a fitted Volterra Series solution. The model requires as input an excitation wavef...

In this paper, we pursue the study of the radar ambiguity problem started in [Ja, GJP]. More precisely, for a given function u we ask for all functions v (called ambiguity partners) such that the ambiguity functions of u and v have same modulus. In some cases, v may be given by some elementary transformation of u and is then called a trivial partner of u otherwise we call it a strange partner. ...