In this paper a novel method for detecting targets in inactive radars is presented. In this method, the time history of cellsof the ambiguity function is used for detection. For this purpose, the cell history is considered as a random field. Then, using adaptive filter, the string time of the desired target are separated from the string time of noise and clusters in the environment. In order to...

For Global Navigation Satellite System (GNSS) single frequency, single epoch attitude determination, this paper proposes a new reliable method with baseline vector constraint. First, prior knowledge of baseline length, heading, and pitch obtained from other navigation equipment or sensors are used to reconstruct objective function rigorously. Then, searching strategy is improved. It substitutes...

The ambiguity function that results from the space-variant optical processing of nonlinear coded waveforms is analyzed. The space-variant signal processor considered is realized by coordinate transformations. Specifically we consider x = lnt, which results in a Mellin transform-based Doppler-invariant signal processor. Ambiguity function data are provided for a nonlinearly coded 13-bit Barker c...

Médard and Gallager recently showed that very large bandwidths on certain fading channels cannot be effectively used by direct sequence or related spread-spectrum systems. This paper complements the work of Médard and Gallager. First, it is shown that a key information-theoretic inequality of Médard and Gallager can be directly derived using the theory of capacity per unit cost, for a certain f...

Global positioning system (GPS) technology is well suited for attitude determination. However, in land vehicle application, low-cost single frequency GPS receivers which have low measurement quality are often used, and external factors such as multipath and low satellite visibility in the densely built-up urban environment further degrade the quality of the GPS measurements. Due to the low-qual...

This paper presents a joint estimation method of source range and depth using a bottom-deployed vertical line array (VLA). The method utilizes the information on the arrival angle of direct (D) path in space domain and the interference characteristic of D and surface-reflected (SR) paths in frequency domain. The former is related to a ray tracing technique to backpropagate the rays and produces...

We propose novel algorithms to select and extract separately all the components, using the time-frequency distribution (TFD), of a given multicomponent frequency-modulated (FM) signal. These algorithms do not use any a priori information about the various components. However, their performances highly depend on the cross-terms suppression ability and high time-frequency resolution of the consid...

design, simulation and optimal selection of cosine-linear frequency modulation waveform (cnlfm) based on correlated ambiguity function (af) method for the purpose of synthetic aperture radar (sar) is done in this article. the selected optimum cnlfm waveform in contribution with other waveforms are applied directly into a sar image formation algorithm (ifa) and their quality effects performance ...