This paper addresses a target detection problem for which the covariance matrix of the unknown Gaussian clutter background has block diagonal structure This block diagonal structure is the consequence of the target lying along a boundary between two statistically independent clutter regions Here we design adaptive detection algorithmsusing both the generalized likelihood ratio GLR and invarianc...

This contribution presents some initial results from investigations into detection of weather radar clutter by data fusion with satellite-based nowcasting products. Weather radar data from three C-band Doppler weather radars of the Danish Meteorological Institute has been extracted for cases of sea and land clutter caused by anomalous propagation as well as cases of clutter free data. In additi...

Space-time adaptive processing (STAP) is an effective tool for detecting a moving target in spaceborne or airborne radar systems. Statistical-based STAP methods generally need sufficient statistically independent and identically distributed (IID) training data to estimate the clutter characteristics. However, most actual clutter scenarios appear only locally stationary and lack sufficient IID t...

Coherent interferometry is an array imaging method in which we back propagate, or migrate, crosscorrelations of the traces over appropriately chosen space-time windows, rather than the traces themselves. The size of the space-time windows is critical and depends on two parameters. One is the decoherence frequency, which is proportional to the reciprocal of the delay spread in the traces produce...

Maritime surveillance of the Exclusive Economic Zone (EEZ) is a present military and civilian challenge. The High Frequency Surface Wave Radar, as its coverage range is not limited by the radio horizon, is well-suited to fulfil this task. HFSWRs are based on the ability of HF waves (3 MHz to 30 MHz) to propagate along the earth curvature: it is possible to detect targets up to few hundred kilom...

HF radar can provide Over the Horizon detection of ships on very large oceanic areas, making use of the ionospheric refraction of radio waves. The Doppler spectrum of the sea clutter is composed of the first-order Bragg lines with a second-order continuum, as described in [1]. Normally, the Doppler shift produces by ships is small, of the same order of magnitude of the Doppler shift of the sea ...

This paper addresses the problem of adaptively canceling both conventional clutter and terrain-scattered jamming (TSJ) in airborne radar systems. Existing algorithms for this type of interference adapt first in space/fast-time to cancel the TSJ, then in space/slow-time to cancel the conventional clutter. Unfortunately, the rapid weight updating required to cancel the nonstationary TSJ will modu...

In order t o reduce false alarms and t o improve the target detection performance of an automatic target detection and recognition system operating in a cluttered environment, it is important t o develop the models not only for man-made targets but also of natural background clutters. Because of the high complexity of natural clutters, this clutter model can only be reliably built through learn...

Let F be a binary clutter. We prove that if F is non-ideal, then either F or its blocker b(F) has one of L7,O5,LC7 as a minor. L7 is the non-ideal clutter of the lines of the Fano plane, O5 is the non-ideal clutter of odd circuits of the complete graph K5, and the two-point Fano LC7 is the ideal clutter whose sets are the lines, and their complements, of the Fano plane that contain exactly one ...

Many environmental factors may contribute to acoustic clutter and adversely affect the performance of tactical sonar by introducing false alarms in the system. During the Main Acoustic Experiment (MAE) 2003 of the Acoustic Clutter program, densely populated fish shoals were identified to be the dominant cause of shallow water acoustic clutter in the New Jersey Continental Shelf. The mixing of c...