Test results using a prototype synthetic aperture sonar

Abstract

In this paper, the operation is described of a prototype coherent synthetic aperture sonar (SAS) based on continuous transmission frequency modulation that covers a 1-octave bandwidth. Images calculated from real data (collected from a sonar range in Loch Linnhe, Scotland) show that it is now possible to produce high-quality images of the seafloor at realistic mapping rates. An air-filled steel buoy was used as a test target, and several images are shown of this target using a variety of reconstruction algorithms.

Synthetic Aperture Sonar: The Past, the Present and the Future

“…The second was the random motion of the sonar platform as well as acoustic path-length variations caused by medium induced turbulence. In 1986, Gough [9] published an article of an experimental SAS using air acoustics but otherwise a scaled replica of what would be later deployed in water as the first KiwiSAS [10,11]. Unfortunately in [9], he also mistakenly claimed to be able to improve the along-track sampling rate by increasing the system bandwidth.…”

Unified framework for modern synthetic aperture imaging algorithms

“…In this case, the aperture is undersampled and we lose valuby reinserting the linear FM waveform we originally removed able information. Unless that information can be recovered using from Ss (v, u) in Equation (38) to obtain some other a priori information, there is little that can be done. However, the a priori information can often impose quite powerful constraints.…”

“…as a major problem, and some experimental SAS systems resorted to rail-or wire-guided bodies to remove that extra complication Walker is credited with the concept of spotlight SAR in 1980 [15,16] (the systems mentioned by Kirk in 1975 [10] and [37,38]. There have been a number of tank experimental SAS systems [39,40], some to look at interferometric SAS [41], and Brookner in 1978 [17] have a fixed squint angle, and so are not true spotlight systems).…”

Motion compensation by phase correction for synthetic‐aperture side‐scan sonar imaging

“…However, platform motion caused by medium perturbations represents a fundamental technical difficulty. To achieve high-resolution synthetic-aperture sonar imaging, the capability of motion estimation and correction has become a key objective (Gough and Hayes, 1989;Kirk, 1975;Mims and Farrell, 1972). In this article, we present an effective approach to accurate motion compensation for high-resolution synthetic-aperture sidescan sonar imaging.…”