## Filter Results

Displaying Results 1 - 18 of 18
• ### False detections in Klein Heidelberg

Publication Year: 2012, Page(s):413 - 416
Cited by:  Papers (2)
| | PDF (169 KB)

The first modern bistatic radar system, Klein Heidelberg (KH), was developed by the Germans during World War II to exploit the transmissions from the British Chain Home (CH) radars and achieved detection ranges against Allied bombers well behind CH. The small backlobe of the system would also have unavoidably detected German aircraft flying behind KH. After estimating the front-back ratio of the a... View full abstract»

• ### Polarisation diversity of conformal arrays based on geometric algebra via convex optimisation

Publication Year: 2012, Page(s):417 - 424
Cited by:  Papers (2)
| | PDF (520 KB)

A simple and general design procedure is presented for the polarisation diversity of arbitrary conformal arrays; this procedure is based on the mathematical framework of geometric algebra and can be solved optimally using convex optimisation. Aside from being simpler and more direct than other derivations in the literature, this derivation is also entirely general in that it expresses the transfor... View full abstract»

• ### Ship detection and speed estimation based on azimuth scanning mode of synthetic aperture radar

Publication Year: 2012, Page(s):425 - 431
| | PDF (587 KB)

A novel technique is presented for the ship detection and ship speed estimation based on the azimuth scanning mode of synthetic aperture radar. The improved Doppler beam sharpening imaging algorithm is used to produce a sequence of individual sub-images of ships in the same scan region from different aspect angles with a high revisit rate. These sub-images have an inherent property that they are f... View full abstract»

• ### Synthesis of monopulse time-modulated planar arrays with controlled sideband radiation

Publication Year: 2012, Page(s):432 - 442
Cited by:  Papers (1)
| | PDF (1170 KB)

The synthesis of time-modulated planar arrays for the design of monopulse antennas is addressed. The sum beam is generated through an optimal set of static excitations and the difference beam is yielded by aggregating the array elements into sub-arrays suitably modulated in time by means of a set of radio-frequency (RF) switches. Towards this aim, an analytically based iterative deterministic appr... View full abstract»

Publication Year: 2012, Page(s):443 - 457
Cited by:  Papers (2)
| | PDF (1110 KB)

This study proposes a multiplexing scheme capable of adaptively responding to various forms of interference. The scheme comprises a signal detector, decision logic and interference mitigation modules. Following the detection and characterisation of interference, decision logic is used to select a specific interference mitigation module to effectively nullify or remove that form of interference. Th... View full abstract»

• ### Improved multi-target multi-Bernoulli filter

Publication Year: 2012, Page(s):458 - 464
Cited by:  Papers (6)
| | PDF (403 KB)

The cardinality-balanced multi-target multi-Bernoulli (CBMeMBer) filter is a promising algorithm for multi-target tracking. However, there exists a problem that when the legacy tracks cardinality is big enough, the effect of measurement innovation will be negligible, even if the measurement is close to the target state prediction. Such a problem is shown analytically in this study, and then an imp... View full abstract»

• ### Synthetic aperture radar autofocus based on projection approximation subspace tracking

Publication Year: 2012, Page(s):465 - 471
Cited by:  Papers (3)
| | PDF (786 KB)

An eigenvector method for maximum-likelihood estimation (MLE) of phase error has better algorithmic performance than phase gradient autofocus (PGA), which is implemented by the simultaneous processing of multiple-pulse vectors of the range-compressed data. However, this method requires eigendecomposition of the sample covariance matrix, which is a computationally expensive task and also limits the... View full abstract»

• ### Model and signal processing of bistatic frequencymodulated continuous wave synthetic aperture radar

Publication Year: 2012, Page(s):472 - 482
Cited by:  Papers (1)
| | PDF (636 KB)

Bistatic frequency-modulated continuous wave (FMCW) synthetic aperture radar (SAR) mounts the radar transmitter and receiver on separate platforms, which offers considerable capabilities, reliability and flexibility in designing FMCW SAR missions. Moreover, the spatial separation achieves better isolation between transmission and reception channels compared with the monostatic FMCW SAR where the t... View full abstract»

• ### Adaptive detection of distributed targets with orthogonal rejection

Publication Year: 2012, Page(s):483 - 493
Cited by:  Papers (13)
| | PDF (768 KB)

This study deals with the problem of detecting distributed targets in the presence of homogeneous and partially homogeneous Gaussian disturbance with unknown covariance matrix. The proposed detectors improve the adaptive beamformer orthogonal rejection test (ABORT) idea to address detection of distributed targets, which makes it possible to decide whether some observations contain a useful target ... View full abstract»

• ### Real-time reconstruction of three-dimensional cylindrical near-field radar images using a single instruction multiple data interpolation approach

Publication Year: 2012, Page(s):494 - 506
| | PDF (959 KB)

During the last decade, radar imaging has been used in near-field scenarios where a cylindrical scan geometry is required to properly illuminate the scan region, such as breast microwave radar imaging and microwave wood inspection. Nevertheless, current cylindrical near-field radar image formation algorithms are not fast enough to provide the throughput required by these novel applications. A real... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Editorial - biologically-inspired radar and sonar systems

Publication Year: 2012, Page(s):507 - 509
Cited by:  Papers (1)
| | PDF (86 KB)

In the last century both radar and sonar active technology developed from inception to the point where high resolution images can be obtained from long ranges. The available technology can exploit Doppler effects, structural resonances, nonlinear scattering, synthetic aperture platforms, and sediment-penetrating modalities. Active sonar and radar share many common approaches, in part because of th... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Use of clicks resembling those of the Atlantic bottlenose dolphin (tursiops truncatus) to improve target discrimination in bubbly water with biased pulse summation sonar

Publication Year: 2012, Page(s):510 - 515
Cited by:  Papers (1)
| | PDF (419 KB)

Dolphins are known to outperform man-made sonar in detecting and classifying targets in a shallow water environment where the returned signal is dominated by clutter in the vicinity of targets. During target interrogation, some species (such as the Atlantic bottlenose dolphin, Tursiops truncatus) emit trains of clicks. Each click can be modelled as consisting of two distinct down-chirping c... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Evaluating three-dimensional localisation information generated by bio-inspired in-air sonar

Publication Year: 2012, Page(s):516 - 525
| | PDF (820 KB)

This study aims to provide a better understanding of how bat bio-sonar operates so that the authors can apply this improved understanding to the design of simple in-air sonar systems based on the same operational principles. It focuses on the effect of component and configuration choices on the generated binaural spectral cues. Configurations composed of conventional receivers are evaluated for va... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Bionic vision-based synthetic aperture radar image edge detection method in non-subsampled contourlet transform domain

Publication Year: 2012, Page(s):526 - 535
Cited by:  Papers (3)
| | PDF (589 KB)

For synthetic aperture radar (SAR) images, traditional edge detection methods can hardly extract the complete and true edges since they are sensitive to noise. In this study, the authors propose an edge detection method based on bionic vision in non-subsampled contourlet transform (NSCT) domain for SAR images, which makes use of the characteristics of NSCT (e.g. multiscale, multidirection edge exp... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Analysis of acoustic echoes from a bat-pollinated plant species: insight into strategies for radar and sonar target classification

Publication Year: 2012, Page(s):536 - 544
Cited by:  Papers (8)
| | PDF (709 KB)

Automatic target classification under all conditions is a key challenge for modern radar and sonar systems. Echolocating nectar feeding bats are able to detect and select flowers of bat-pollinated plants even in highly cluttered environments. It is thought that these flowers have evolved to ease classification by bats, and that their echo-acoustic signatures contain critical information that aids ... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Review of the occurrence of multiple pulse echolocation clicks in recordings from small odontocetes

Publication Year: 2012, Page(s):545 - 555
| | PDF (587 KB)

This study investigates the extent of the possible correlation between small odontocetes that predominantly inhabit littoral waters, and those which have been associated with the detection of echolocation clicks that consist of multiple pulses. The echolocation clicks discussed are primarily characterised as short, high frequency (>;100>;kHz) and narrow band. There are many sources that repo... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Bbiosonar echo processing by frequency-modulated bats

Publication Year: 2012, Page(s):556 - 565
Cited by:  Papers (9)
| | PDF (643 KB)

Big brown bats emit brief frequency-modulated (FM) biosonar signals in the 20-100-kHz frequency band. They use a unique delay-based processing method to focus target images and defocus clutter. Broadcasts and echoes are received by the ears and encoded as spectrogram-like representations by parallel auditory band-pass filters. Neural responses to successive frequencies in broadcasts travel along p... View full abstract»

• ### Special section on biologically-inspired radar and sonar systems - Why dolphin biosonar performs so well in spite of mediocre 'equipment'

Publication Year: 2012, Page(s):566 - 575
Cited by:  Papers (10)
| | PDF (993 KB)

Dolphins have been found to have an excellent sonar system that is able to detect and recognise targets in noisy and highly reverberant environments. However, their equipment has only mediocre characteristics from a technological sonar perspective. How dolphins perform the biosonar task so well is addressed in this manuscript. Echolocating dolphins have the capability to make fine discrimination... View full abstract»