The local polynomial Fourier transform (LPFT) based algorithm for autofocusing SAR images has recently been proposed by the authors. It produces a well focused image of moving targets, without defocusing stationary targets or inducing undesired cross-terms. The drawback of this algorithm is its high computational burden caused by the large number of elements in the set of used chirp-rates. We p...

In this paper we extend Wilcox’s classical results to the case of subregions of R2. This generalization enables us to construct many promising new waveforms with desired ambiguity profiles in the regions being considered. Key-Words: Radar waveform design, Ambiguity function, Non-linear optimization, Hermite waveform.

In previous work, the spread has been presented as a means to quantify nonstationarity. This is done by estimating the support of the joint time-frequency correlation function known as the expected ambiguity function. Two fundamental issues concerning the spread are addressed here. The first is that the spread is not invariant under basis transformation. We address this problem by introducing t...

CAZAC (Constant Amplitude Zero Auto-Correlation) sequences are important in waveform design because of their optimal transmission efficiency and tight time localization properties. Certain classes of CAZAC sequences have been used in radar processing for many years, while recently discovered sequences invite further study. This paper compares different classes of CAZAC sequences with respect to...

We propose equilibrium notions for incomplete information games involving players who perceive ambiguity about the types of others. Players have smooth ambiguity preferences (Klibanoff, Marinacci and Mukerji, 2005) and may be ambiguity averse. In the smooth ambiguity model it is possible to hold the agents’information fixed while varying the agent’s ambiguity attitude from aversion to neutralit...

In this paper, a new method of pulse compression polyphase code synthesis based on the aperiodic autocorrelation function properties and the assumption of coherent processing in the radar receiver is presented. Properties of the proposed code, including spectrum, ambiguity function, precompression bandlimiting effects, and the noise/clutter influence are analyzed. The main features of the synth...

Abstract: Sudoku puzzles, often seen in magazines and newspapers, are logic-based challenges where each entry within the puzzle is comprised of symbols adhering to row, column and box constraints. Previously, we had investigated their potential in frequency-hopped waveforms to achieve desirable radar ambiguity functions and compared them with random, as well as the more familiar Costas sequence...

Matchedeld methods are known to have a severe ambiguity problem. In low signal-to-noise-ratios (SNR's), where the estimator cannot distinguish between the ambiguity function peak near the true source location and ambiguous ones, its mean square error deviates radically from the Cramer-Rao lower bound (CRLB). In this paper, the Barankin bound for the source localization problem in an uncertain s...

When point calibration targets are used to calibrate a SAR image, the calibration accuracy is governed by two major factors. The first factor stems from the stringent requirement on the radar cross section (RCS) of the point calibration target. To reduce the effect of radar return from the background, the RCS of a point calibration target must be much larger than that of the background. Calibra...

When ambiguity-averse investors process news of uncertain quality, they act as if they take a worst-case assessment of quality. As a result, they react more strongly to bad news than to good news. They also dislike assets for which information quality is poor, especially when the underlying fundamentals are volatile. These effects induce ambiguity premia that depend on idiosyncratic risk in fun...