Sonar Signal Enhancement Using Fractional Fourier Transform

Acoustic Seabed Classification using Fractional Fourier Transform

In this paper we present a time-frequency approach for acoustic seabed classification. Work reported is based on sonar data collected by the Volume Search Sonar (VSS), one of the five sonar systems in the AN/AQS-20. The Volume Search Sonar is a beamformed multibeam sonar system with 27 fore and 27 aft beams, covering almost the entire water volume (from above horizontal, through vertical, back ...

Chapter 5 Target Detection in Active Sonar using Fractional Fourier Transform

Radar Matched Filtering using the Fractional Fourier Transform

A matched filter is the optimal linear filter for maximizing the signal to noise ratio (SNR) in the presence of additive noise. Matched filters are commonly used in radar systems where the transmitted signal is known and may be used as a replica to be correlated with the received signal which can be carried out by multiplication in the frequency domain by applying Fourier Transform (FT). Fracti...

Subsample Time delay estimation using fractional Fourier transform

The need for subsample time delay estimation (TDE) between two signals arises quite often in many areas such as radar; sonar etc. In this paper, the use of fractional Fourier transform (FRFT) for subsample TDE is proposed. The proposed estimator uses the magnitude of the FRFT of the signals, although the phase angle of it can also be exploited for the estimation purpose. To validate the propose...

Time-Frequency Transform Techniques for Seabed and Buried Target Classification

An approach for processing sonar signals with the ultimate goal of ocean bottom sediment classification and underwater buried target classification is presented in this paper. Work reported for sediment classification is based on sonar data collected by one of the AN/AQS-20’s sonars. Synthetic data, simulating data acquired by parametric sonar, is employed for target classification. The techniq...