• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.141-151
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• 2019

In this study, we propose a performance analysis of a quadrature-polarimetric(quad-pol) synthetic aperture radar(SAR) system for wide-swath operation mode and compare it with a single-pol system based on the operation mode. To achieve a shorter revisit time for an SAR satellite, we must observe a wide area, and two SAR operation modes exist for this purpose, which are called ScanSAR and SweepSAR. In general, a quad-pol SAR system can obtain a greater variety of information about a target than a single-pol system. Because this system affects system performance parameters, analyzing these effects is required. Based on a performance analysis of the wide-swath quad-pol SAR system, the system parameters and appropriate operation mode can be selected to satisfy the performance requirements.

• Journal of Satellite, Information and Communications
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• v.1 no.1
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• pp.26-39
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• 2006

A synthetic aperture radar (SAR) system can provide all-weather, day and night imaging capability, and thus, is very useful in surveillance for both civil and military applications. In this paper, the X-band spaceborne SAR system design procedure is introduced with the key design parameters for mission and system requirements characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the design results are analyzed for standard mode performance evaluation. In line with the system requirements, the X-band SAR payload and ground reception/processing sub-systems are presented with the key design results and image applications examples. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.

• Korean Journal of Remote Sensing
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• v.16 no.2
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• pp.157-175
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• 2000

A synthetic aperture radar (SAR) system is able to provide all-weather, day-and- night superior imaging capability of the earth surface, and thus is extremely useful in surveillance for both civil and military applications. In this paper, the X-band high resolution spaceborne SAR system design is demonstrated with the key design performance for a given mission and system requirements characterized by the small satellite system. The SAR multi-mode imaging technique is presented with a critical parameter assessment, and the standard mode results are analyzed in terms of the image quality performances. In line with the system requirement X-band SAR payload and ground reception/processing subsystems are designed and the major design results are presented with the key performance characteristics. This small satellite SAR system shows the wide range of imaging capability with high resolution, and proves to be an effective surveillance systems in the light weight, high performance and cost-effective points of view.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.8
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• pp.624-631
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• 2018

To meet the requirements of various satellite synthetic aperture radar(SAR) system performance parameters, the characteristics of the antenna pattern should be analyzed. In this paper, we propose a method to improve the SAR system performance using an effective technique for optimizing antenna pattern synthesis in the presence of element failure. The desired antenna pattern can be synthesized by referring to the optimized antenna mask templates using the particle swarm optimization algorithm. In the simulation, the performance of the proposed method is verified by analyzing characteristics related to the SAR system performance parameters using antenna pattern regeneration.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.7
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• pp.1258-1270
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• 2000

A synthetic aperture radar (SAR) system is able to provide all-weather, day-and-night, high resolution imaging capability in the wide area of interest, and thus is extremely useful in surveillance for both civil and military applications. In this paper, the X-band high-resolution spaceborne SAR system design is described with the key design parameters for the mission and system requirement characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the standard imaging mode design results are analyzed with respect to image quality performance. In line with the system requirement, X-band SAR payload and ground reception/processing subsystems are designed and the key design results are demonstrated with the outstanding performance characteristics. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance systems in the light weight, high performance and cost-effective points of view.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.1
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• pp.104-123
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• 2001

Synthetic Aperture Radar(SAR) can provide radar imagery in all weather, day and night situations. Recently SAR system consisted of several imaging modes, has been used for not only military purpose, but also commercial and scientific applications. This paper firstly reviews spaceborne SAR theory, specially scansar principle, and secondly the theories and the design procedures of system performance analysis in the scansar mode, which are different from the ones in the conventional stripmap mode. Based on the SAR-related knowledge, it lastly derives the results of performance analysis in wide swath mode using the scansar technique at the design phase. It shows that these results can meet the system requirements as given the customer. In future, they will continuously be updated using the real measurement data, in connection with the development of a spaceborne SAR system.

• Journal of the Korea Institute of Military Science and Technology
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• v.3 no.2
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• pp.101-120
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• 2000

A synthetic aperture radar (SAR) system can provide all-weather, day and night, superior imaging capability, and thus is very useful in surveillance for military applications. In this paper, a X-band spaceborne SAR system design concept is introduced with the key design parameters for mission and system requirements characterized by small satellite system. The SAR imaging mode design procedure is presented, and the standard imaging mode design results are analyzed as an example. In line with the given mission and system requirements, the X-band SAR payload and ground reception/processing subsystems are designed and presented with the key design results. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.118-127
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• 2018

In this work, we have designed and manufactured radar target simulation equipment for the performance analysis of synthetic aperture radar(SAR) systems. First, we have explained the function and performance specification of the target simulation equipment and point target scenario generation for validation of the SAR system. In addition, we have developed a simple and accurate calibration method for the time delay of the SAR system using the manufactured target simulation equipment. We have analyzed the point target impulse response function of the SAR image acquired using the SAR system and the target simulation equipment. It was observed that the measured peak to side lobe ratio(=-13.25 dB) and resolution(=0.49 m) are in good agreement with the corresponding theoretical values.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.737-743
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• 2002

It is an essential design process to analyze the performance of Synthetic Aperture Radar (SAR) processor before implementation. The contribution of this paper is to identify the chief sources and types of errors, to assess their impact on system performance, and to suggest the analysis technique for principal performance of the space-based SAR processor using Range-Doppler Algorithm (RDA). Also, simulation is performed by the Experimental-SAR (E-SAR) processor to examine the practicability and efficiency of the technique, the results are discussed, and solutions for the problems are recommended. Therefore, this technique can be used to analyze the performance of the space-based SAR processor using RDA.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.118-128
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• 2017

In this study, we propose a real time inertial navigation system/global positioning system (INS/GPS) integrated smoothing algorithm based on an extended Kalman filter (EKF) and a position damping loop (PDL) for synthetic aperture radar (SAR). Integrated navigation algorithms usually induce discontinuities due to error correction update by the Kalman filter, which are as detrimental to the performance of SAR as the relative position error. The proposed smoothing algorithm suppresses these discontinuities and also reduces the relative position error in real time. An EKF estimates the navigation errors and sensor biases, and all the errors except for the position error are corrected directly and instantly. A PDL activated during SAR operation period imposes damping effects on the position error estimates, where the estimated position error is corrected smoothly and gradually, which contributes to the real time smoothing and small relative position errors. The residual errors are re-estimated by the EKF to maintain the estimation performance and the stability of the overall loop. The performance improvements were confirmed by Monte Carlo simulations. The simulation results showed that the discontinuities were reduced by 99.8% and the relative position error by 48% compared with a conventional EKF without a smoothing loop, thereby satisfying the basic performance requirements for SAR operation. The proposed algorithm may be applicable to low cost SAR systems which use a conventional INS/GPS without changing their hardware configurations.