Digital Signal Processing

Y. Ramana Murty ¹, M. Bala Krishna ¹, M. N. V. S. S. Kumar ¹

Affiliations
1 Aditya Institute of Technology and Management, Tekkali, IN

Abstract

Avoiding collision of the Autonomous underwater vehicle (AUV) with the floating or fixed objects in the underwater scenario needs either apriori knowledge of the operating environment or sensing equipment for evaluating the environment in real time. The sensing equipment in this case is the forward looking Sonar that is mounted on the AUV which scans the area in front and provides the images as the output. The technology used in this forward looking SONAR is CHIRP. In SONAR, Surface Acoustic Wave devices such as Reflective array Compressors are used to generate the chirped signals. Because of Chirp technology high resolution images of sea bed are produced. The range resolution of the CHIRP technology SONAR is much better than conventional monotonic SONAR. With monotonic SONAR it is very difficult to differentiate two objects separated by less than 37.5 mm whereas using CHIRP technology SONAR it is easy to distinguish the objects if they 7.5mm apart. In this paper the generation of Chirp pulse is analyzed. The pulse compression technique and different windowing techniques are analyzed to detect the peak of the received signal.

Keywords

Chirp, Range Resolution, Pulse Compression.

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L. Vijaya Lakshmi ¹, A. Jaya Laxmi ², M. N. V. S. S. Kumar ¹, P. Sirish Kumar ¹

Affiliations
1 Department of ECE, Aditya Institute of Technology and Management, Tekkali, Andhra Pradesh, IN
2 Department of ECE, Aditya Institute of Technology and Management, Tekkali, Andhra Pradesh

Abstract

It is very important to know the characterization of targets using radar. It is extensively used in various applications. The polarization properties are important for radar target besides amplitude, phase and frequency. The polarization may be potentially used to improve target detection, anti-interference, and radar target recognition. Characteristics of the target can be known by using the polarization properties of that particular target. This depends upon scattering nature of the target. Using polarization scattering matrix (PSM), we can obtain the properties of the target. The derivations of scattering matrix for some other various geometrical shapes are presented in this paper. By using the method of the properties of polarization scattering matrix (PPSM) for radar target recognition (RTR) is presented in this paper. The polarization matrix and properties for a dipole is calculated by considering that dipole as target. These properties of the polarization scattering matrix are analyzed for different orientation angles for a target.

Keywords

Polarization, Scattering Matrix.

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