GigaRad – a multi-purpose high-resolution ground-based radar – system concept, error correction strategies and performance verification

2015 ◽  
Vol 7 (3-4) ◽  
pp. 443-451 ◽  
Author(s):  
Matthias Jirousek ◽  
Sebastian Iff ◽  
Simon Anger ◽  
Markus Peichl
Keyword(s):  
Synthetic Aperture Radar ◽  
Error Correction ◽  
High Performance ◽  
Radar System ◽  
Synthetic Aperture ◽  
Absolute Calibration ◽  
Range Resolution ◽  
Imaging Results ◽  
High Flexibility ◽  
Aperture Radar

Recently DLR has developed and constructed a new experimental radar instrument [5] for various applications such as radar signature collection, synthetic aperture radar/inverse synthetic aperture radarimaging, motion detection, tracking, etc., where high performance and high flexibility have been the key drivers for system design. Consequently the multi-purpose and multi-channel radar called GigaRad is operated in X and Ku band and allows an overall bandwidth of up to 6 GHz, resulting in a theoretical range resolution of up to 2.5 cm. Hence, primary obligation is a detailed analysis of various possible error sources, being of no or less relevance for low-resolution systems. A high degree of digital technology enables advanced signal processing and error correction to be applied. The paper outlines main technical features of the radar system, the basic error correction and absolute calibration strategy, frequency limitations, and illustrates some imaging results.

scholarly journals Analysis and Simulation on Imaging Performance of Backward and Forward Bistatic Synthetic Aperture Radar

2018 ◽  
Vol 10 (11) ◽  
pp. 1676 ◽  
Author(s):  
Tingting Li ◽  
Kun-Shan Chen ◽  
Ming Jin
Keyword(s):  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Forward Region ◽  
Range Resolution ◽  
Bistatic Sar ◽  
Imaging Results ◽  
Sar Imaging ◽  
Bistatic Synthetic Aperture Radar ◽  
Motion Parameters ◽  
Aperture Radar

In recent years, bistatic synthetic aperture radar (SAR) technique has attracted considerable and increasing attention. Compared to monostatic SAR for which only the backscattering is measured, bistatic SAR expands the scattering measurements in aspects of angular region and polarization, and greatly enhances the capability of remote sensing over terrain and sea. It has been pointed out in recent theoretical researches that bistatic scattering measured in the forward region is preferable to that measured in the backward region in lines of surface parameters retrieval. In the forward region, both dynamic range and signal sensitivity increase to a great extent. For these reasons, bistatic SAR imaging is desirable. However, because of the separated positions of the transmitter and receiver, the degrees of freedom in the parameter space is increased and the forward bistatic imaging is more complicated than the backward bistatic SAR in the aspects of bistatic range history, Doppler parameter estimation and motion compensation, et, al. In this study, we analyze bistatic SAR in terms of ground range resolution, azimuth resolution, bistatic range history and signal to noise ratio (SNR) in different bistatic configurations. Effects of system motion parameters on bistatic SAR imaging are investigated through analytical modeling and numerical simulations. The results indicate that the range resolution is extremely degraded in some cases in forward bistatic SAR imaging. In addition, due to the different imaging projection rules between backward and forward bistatic SAR, the ghost point is produced in the forward imaging. To avoid the above problems, the forward bistatic imaging geometry must be carefully considered. For a given application requirement with the desired imaging performances, the design of the motion parameters can be considered as a question of solving the nonlinear equation system (NES). Then the improved chaos particle swarm optimization (CPSO) is introduced to solve the NES and obtain the optimal solutions. And the simulated imaging results are used to test and verify the effectiveness of CPSO. The results help to deepen understanding of the constraints and properties of bistatic SAR imaging and provide the reference to the optimal design of the motion parameters for a specific requirement, especially in forward bistatic configurations.

scholarly journals Experimental Research on Interferometric Inverse Synthetic Aperture Radar Imaging with Multi-Channel Terahertz Radar System

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2330 ◽  
Author(s):  
Ye Zhang ◽  
Qi Yang ◽  
Bin Deng ◽  
Yuliang Qin ◽  
Hongqiang Wang
Keyword(s):  
Synthetic Aperture Radar ◽  
Radar System ◽  
Superior Performance ◽  
Projection Algorithm ◽  
Synthetic Aperture ◽  
Signal Frequency ◽  
Inverse Synthetic Aperture Radar ◽  
Microwave Radar ◽  
Imaging Results ◽  
Aperture Radar

The all solid-state terahertz (THz) radar has obvious miniaturized integration and high resolution imaging advantages compared with conventional microwave radar. In this paper, a 0.22 THz active frequency-modulated pulse radar system with one transmission channel and four receiving channels is presented, and interferometric inverse synthetic aperture radar (InISAR) imaging experiments, which can acquire altitude information of objects, are carried out. In order to acquire high-quality InISAR images, a calibration method is presented to solve the nonlinearity of wideband signal frequency and phase inconsistency of different receiving channels together. Furthermore, to deal with the phase wrapping in InISAR imaging of objects with large scale, a novel method based on the dominant scatterers to estimate the objects rotation rate is presented. Finally, to show more information of objects in the InISAR images, the imaging results with a large rotation angle by the convolutional back-projection algorithm are obtained. The imaging results verify the superior performance of the multi-channel THz radar system and the imaging processing method, which can provide support for further research on InISAR imaging in the THz band.

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