This study proposes an alternative effective sonar image enhancement algorithm. The method basically composes of two steps, including noise reduction and image sharpening. The sonar image is first de-noised using Wiener and median filters, and then it is enhanced using unsharp masking and histogram equalization. The proposed algorithm has been verified on many sonar images of different underwat...

A Phased Array Doppler Sonar (PADS), as developed at SIO, images both acoustic backscatter intensity and Doppler shift over areas up to 90 degrees in bearing by 500 m in range. Sequences of images are recorded continuously for up to two months, with individual “pings” 0.5 to 1.0 seconds apart. The images permit two independent estimates of the mean velocity to be formed over the imaged area: on...

Abstract Modeling of broadband and narrowband signal mark detection is widely used for sonar radar systems. In this work, the problem considered in relation to hydroacoustics. The paper describes formation a stream correctly detected false marks calculation estimates their parameters, taking into account antenna characteristics as well processing parameters system being simulated. Also are real...

Under special condition, the surface target could be attacked by submarine with two wire-guided torpedoes passive acoustic homing mode. When device detects bearing and transmit it back to through wire, a three-sensor detection system is constituted submarine’s integrated sonar torpedoes. Whether can effectively track related observability of system. Only satisfying observable conditions moving ...

Target class measurements, if available from automatic target recognition systems, can be incorporated into multiple target tracking algorithms to improve measurement-to-track association accuracy. In this work, the performance of the classifier is modeled as a confusion matrix, whose entries are target class likelihood functions that are used to modify the update equations of the recently deri...

In this paper, we present a computationally simple algorithm suitable for fast, high resolution estimation of time delays and doppler shifts (which are necessary for target localization and tracking) between narrowband signals in an active sonar system. The algorithm uses a modulated Lagrange interpolation filter and an LMStype algorithm. The problem of delay and doppler estimation is reduced t...

This paper presents the preliminary studies of a distributed passive sonar system for the localization and tracking of underwater acoustic sources. The techniques under test are one referred to as hyperbolic and mainly developed by Carter and another proposed by the authors and based on neural network processing. Both techniques are supported on the measurement of the relative time delay of an ...

Current passive sonar methods are designed for static fixed or straight towed arrays. Signal processing approaches for such systems are thus seriously degraded by platform maneuvers. In this project, the objectives are to: 1) exploit small platform maneuverability using small broadband acoustic arrays to resolve targets from interferers, and 2) improve the target detection, localization, and tr...

Teleoperation of unmanned aerial vehicles often demands extensive training. Yet, even well trained pilots are prone to mistakes, resulting frequently in collisions of the vehicle with obstacles. This paper presents a method to assist the tele-operation of a quadrotor using an obstacle avoidance approach. In particular, rough map of the nearby environment is constructed using sonar sensors. This...

We describe the application of learining with neural networks and support vector machines on different data sets. We report high results for hepatitis, sonar, and ionosphere, fail completely with a eye tracking data set, and for a natural language learning data set, after desastrous classification rates with more conventional kernel methods, MLPs, and others, we obtain good results with custom ...