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Range Doppler ISAR Imaging Using Chirp Pulse
Published in Anupama Namburu, Soubhagya Sankar Barpanda, Recent Advances in Computer Based Systems, Processes and Applications, 2020
G. V. Sai Swetha, P. Anjali Reddy, A. Naga Jyothi
Inverse Synthetic Aperture Radar (ISAR) is a dominant technique in signal processsing, which provides the electromagnetic image of the target in two dimensions. This radar imaging technique is used in any weather condition. The technique ISAR has been derived from the Synthetic Aperture Radar (SAR) technique. The radar is kept stationary as the target moves round as shown in figure 1. In SAR it increases the size of antenna so as to increase the resolution of the image. As the radar moves, at many positions pulses are being transmitted, and the returned signals (echoes) are increased in antenna aperture [1]. Likewise, the ISAR is employed to produce moving target’s images in Matlab simulation; the rest of the process is similar to the SAR. The techniques SAR and ISAR are being the highly interested platforms for the researches.
Introduction
Published in Hai Deng, Zhe Geng, Radar Networks, 2020
Compared with optical imaging, radar imaging is weather-independent and could be implemented day and night. Moreover, radar waveforms could penetrate ground, water, and walls to generate images of the target. In radar imaging, the two primary figures of merit are spatial resolution and dynamic range (Richards, 2014). Currently, 2D high-resolution images of static ground scenes are often acquired by SAR, while moving targets such as aircrafts and missiles could be imaged using inverse SAR (ISAR). The basic theory behind SAR is that it uses a small antenna array on a moving platform to mimic a much larger antenna array, hence archiving radar images with higher spatial resolution.
Recovery Guarantees for High-Resolution Radar Sensing with Compressive Illumination
Published in C.H. Chen, Compressive Sensing of Earth Observations, 2017
Radar imaging systems acquire information about the scene of interest by transmitting pulsed waveforms and processing the received backscatter energy to form an estimate of the range, angle of arrival, Doppler velocity, and amplitude of the reflectors in the scene. These range profiles from multiple pulses and/or multiple antenna elements can be processed jointly to solve a multitude of inference tasks including detection, tracking, and classification [1]. In this chapter, we focus on coherent multiple-input and multiple-output (MIMO) radar systems with closely separated antennas, such that the angle of arrival of each scatterer in the illuminated scene is approximately the same for all phase centers. The main advantage of coherent MIMO radar is its ability to synthesize a large virtual array with fewer antenna elements for improved spatial processing. Additionally, MIMO radar systems with multiple transmit and receive elements employing independent waveforms on transmit can provide spatial processing gains by exploiting the diversity of channels between targets and radar [2,3].
SAR target recognition using behaviour library of different shapes in different incidence angles and polarisations
Published in International Journal of Electronics, 2018
Mojtaba Behzad Fallahpour, Hamid Dehghani, Ali Jabbar Rashidi, Abbas Sheikhi
SAR imaging systems aim to perform the radar imaging of any given region. Radar imaging is meant to extract the radar cross section (RCS) associated with the surface or volume elements under study, which are available to the users in grey levels in a two-dimensional plane, known as SAR image. In fact, the image obtained from SAR imaging system is the backscatter coefficient of the surficial pixels in microwave frequency (Lin, Wang, Wang, & Liu, 2017).