## Filter Results

Displaying Results 1 - 18 of 18
• ### Guest Editorial: Sonar Multi-sensor Applications and Techniques

Publication Year: 2017, Page(s):1737 - 1739
| PDF (606 KB)
• ### Cooperative robotic networks for underwater surveillance: an overview

Publication Year: 2017, Page(s):1740 - 1761
| | PDF (4356 KB)

Underwater surveillance has traditionally been carried out by means of surface and undersea manned vessels equipped with advanced sensor systems. This approach is often costly and manpower intensive. Marine robotics is an emerging technological area that enables the development of advanced networks for underwater surveillance applications. In contrast with the use of standard assets, these advance... View full abstract»

• ### Rendezvous planning for multiple autonomous underwater vehicles using a Markov decision process

Publication Year: 2017, Page(s):1762 - 1769
| | PDF (2676 KB)

Multiple autonomous underwater vehicles (AUVs) are a potential alternative to conventional large manned vessels for mine countermeasure (MCM) operations. Online mission planning for cooperative multi-AUV network often rely on predefined contingencies of reactive methods and does not deliver an optimal end-goal performance. Markov decision process is a decision-making framework that allows an optim... View full abstract»

• ### Non-myopic sensor scheduling for multistatic sonobuoy fields

Publication Year: 2017, Page(s):1770 - 1775
| | PDF (2277 KB)

Sonobuoy fields, consisting of many distributed emitter and receiver sonar sensors on buoys, are used to seek and track underwater targets in a defined search area. The authors seek a scheduling protocol, selecting both the emitter and its waveform in each time interval that optimises tracking performance. This study describes a stationary scheduling algorithm for sonobuoy fields called the contin... View full abstract»

• ### Constrained robust submodular sensor selection with application to multistatic sonar arrays

Publication Year: 2017, Page(s):1776 - 1781
| | PDF (1920 KB)

The authors develop a framework to select a subset of sensors from a field in which the sensors have an ingrained independence structure. Given an arbitrary independence pattern, the authors construct a graph that denotes pairwise independence between sensors, which means those sensors may operate simultaneously without interfering. The set of all fully-connected subgraphs (cliques) of this indepe... View full abstract»

• ### Hybrid phase shift and shifted sideband beamforming for large-aperture MIMO sonar imaging

Publication Year: 2017, Page(s):1782 - 1789
| | PDF (2902 KB)

A multiple-input multiple-output (MIMO) sonar can form a large-aperture virtual uniform linear array (ULA) from a small number of physical elements. However, the large-aperture MIMO sonar encounters a dilemma between the computation load and the imaging performance. Since the traditional phase-shift beamformer (PSBF) and shifted sideband beamformer (SSBF) cannot solve the dilemma individually, the... View full abstract»

• ### Gaussian mixture multitarget–multisensor Bernoulli tracker for multistatic sonobuoy fields

Publication Year: 2017, Page(s):1790 - 1797
| | PDF (1768 KB)

Sonobuoy fields, consisting of a large network of emitter and receiver sonar sensors on buoys, are increasingly being used for detection and tracking of underwater targets in a defined maritime area. This study presents a Gaussian mixture version of a multitarget-multisensor (MS) Bayesian-type tracker developed specifically for multistatic sonobuoy fields. Its foundation is the optimal Bayesian MS... View full abstract»

• ### Joint DOA and frequency estimation with sub-Nyquist sampling for more sources than sensors

Publication Year: 2017, Page(s):1798 - 1801
| | PDF (1210 KB)

Multiple antenna systems with sub-Nyquist sampling technique have been applied to jointly estimate frequency and direction-of-arrival of narrowband far-field signals. Unlike the current some techniques, where only one signal can be handled in some certain subband, the authors propose a novel technique to deal with the case of multiple signals. The authors first build a new time-space union model f... View full abstract»

• ### Signal censoring and fusing with system-level communication constraints in multistatic radar: a J-divergence and Bhattacharyya distance-based approach

Publication Year: 2017, Page(s):1802 - 1814
| | PDF (4515 KB)

Decentralised detection using censored observations is an effective way to mitigate communication constraints where each sensor only transmits the informative' observations to a fusion centre (FC), and censors those deemed uninformative'. In this study, a censoring rule is used at each spatial diversity channel such that only the observation exceeding a local threshold is transmitted, where the ... View full abstract»

• ### Multi-scan smoothing for tracking manoeuvering target trajectory in heavy cluttered environment

Publication Year: 2017, Page(s):1815 - 1821
| | PDF (3197 KB)

An automatic target tracking algorithm must be capable of dealing with an unknown number of targets and their trajectory behaviour inside the surveillance region. However, due to target motion uncertainties, heavily populated clutter measurements and low detection probabilities of targets, the smoothing algorithms often fail to detect the true number of target trajectories. In this study, the auth... View full abstract»

• ### Synchronisation method for pulsed pseudolite positioning signal under the pulse scheme without slot-permutation

Publication Year: 2017, Page(s):1822 - 1830
| | PDF (2178 KB)

Ground-based pseudolite positioning systems are valuable in environments where global positioning system (GPS) is not available. To mitigate near-far effect, pseudolite positioning systems often use pulsed signals instead of GPS-like continuous signals. The simple pulse scheme without slot-permutation cannot preserve the spectrum shape of the original un-pulsed signal, and this may result in false... View full abstract»

• ### Adaptive beamforming algorithms with robustness against steering vector mismatch of signals

Publication Year: 2017, Page(s):1831 - 1838
| | PDF (5015 KB)

Three novel adaptive beamforming algorithms are developed to mitigate the steering vector (SV) random errors of both the desired signal and interferences. With the use of iterative robust Capon beamforming technique, each interference's SV is estimated first, and then the interference-plus-noise covariance matrix is reconstructed according to its definition. To accurately estimate the signal of in... View full abstract»

• ### Recursive instrumental variable method for locating a scanning emitter by a single observer using time of interception

Publication Year: 2017, Page(s):1839 - 1844
| | PDF (1231 KB)

The recursive solution to passive localisation of a scanning emitter using time of interception (TOI) by a single moving observer is investigated in this study. First, the correlated measurement noise in the traditional pseudo-linear model for the scanning emitter localisation is decoupled by introducing the first noise corrupted direction of arrival as a nuisance parameter. A recursive pseudo-lin... View full abstract»

• ### Robust DFT-based generalised likelihood ratio test for underwater tone detection

Publication Year: 2017, Page(s):1845 - 1853
| | PDF (2938 KB)

The discrete Fourier transform (DFT) of observation sequence is usually used in the detection of tonal signal. A tone without any prior information cannot be guaranteed to lie exactly on the discrete DFT frequency bin, which will degrade the performance of the tonal detector based on DFT. In this work, the authors study the detection problem for a tone deviated from the discrete frequency bin. A g... View full abstract»

• ### Subspace tracking in a sensor array using complex Bingham distribution

Publication Year: 2017, Page(s):1854 - 1864
| | PDF (2700 KB)

This study presents a subspace-based tracking algorithm called Bingham filter using the outputs of a sensor array. Given n sensors in the sensor array with spatially and temporally white Gaussian noise in the outputs of the array, the Bingham filter estimates the signal subspaces generated by the targets based on the phased array observations, a priori information and previous estimates. As... View full abstract»

• ### Mitigation of ionospheric scintillation effect using adaptive PID-based tracking loop in GPS receivers

Publication Year: 2017, Page(s):1865 - 1876
| | PDF (2985 KB)

Ionospheric scintillation caused by charged particles results in rapid phase and amplitude fluctuations of a received GPS signal. This obstacle can degrade and disable some signal processing in the GPS sensors. There is a significant interest in the development of global navigation satellite system sensors that can track through scintillations more reliably than current receivers. This study prese... View full abstract»

• ### Jittered chirp sequence waveform in combination with CS-based unambiguous Doppler processing for automotive frequency-modulated continuous wave radar

Publication Year: 2017, Page(s):1877 - 1885
| | PDF (2676 KB)

The chirp sequence waveform is one of the most commonly used waveforms for automotive frequency-modulated continuous wave radars. When a chirp sequence waveform is applied, the range-Doppler processing method based on two-dimensional fast Fourier transform can be used to extract the range and velocity parameters of multiple targets from the beat signals. However, conventional chirp sequence wavefo... View full abstract»

• ### Sparse sampling-based microwave 3D imaging using interferometry and frequency-domain principal component analysis

Publication Year: 2017, Page(s):1886 - 1891
| | PDF (3109 KB)

Microwave radar 3D imaging with high resolution generally requires a great number of samples. The authors aim at accurate reconstruction of microwave radar images while significantly reducing the required number of samples. A novel algorithm is proposed which realises sparse sampling with nearly 50% data reduction and high-quality restoration, based on interferometry and principal component analys... View full abstract»