• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.1
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• pp.130-138
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• 2003

The classical image reconstruction for stripmap-mode Synthetic Aperture Radar is the Range-Doppler algorithm. When the spotlight-mode SAR system was envisioned, Range-Doppler algorithm turned out to fail rapidly in this SAR imaging modality. Thus, what is referred to as Polar format algorithm, which is based on the Plane wave approximation, was introduced for imaging from spotlight-mode SAR raw- data. In this paper, we have studied for the raw data processing schemes in the spotlight-mode Synthetic Aperture Radar. We apply the Wavefront Reconstruction scheme that does not utilize the approximation in spotlight-mode SAR imaging modelity, and compare the performance of target imaging with the Polar format inversion scheme.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.501-504
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• 2000

The classical image reconstruction for stripmap SAR is the range-Doppler imaging. However, when the spotlight SAR system was envisioned, range-Bowler imaging fumed out to fail rapidly in this SAR imaging modality. What is referred to as polar format processing, which is based on the plane wave approximation, was introduced for imaging from spotlight SAR data. This paper has been studied for the raw data processing schemes in the spotlight-mode synthetic aperture radar. we apply the wavefront reconstruction scheme that does not utilize the approximation in spotlight-mode SAR imaging modelity, and compare the performance of target imaging with the polar format inversion scheme.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.487-492
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• 2012

In this study we researched a spotlight in LED lighting. Ordinary LED spotlight was manufactured with characterized property of traveling straightness of LED light source, but multiple use of shell type LED, a yellow band has formed caused by light source interference between the LED. Also, there was a high miscellaneous light efficiency with losing light source homogeneity and efficiency due to light source control uneasiness. The study uses aspheric reflector and aspheric lens, so we can control the light source of LED spotlight with effectively and we reached surface light source by using COB/COM for LED module. Furthermore it can change its use by a reduced scale of light system. It has been designed to make its various application from low power consumption of bicycle lamp, up to high power consumption of automobile lamps and lighthouse.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.2
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• pp.160-169
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• 2007

In this paper, we have described and simulated the effect analysis and correction of phase errors in the SAR rawdata induced by satellite attitude errors such as drift, jitter. This simulation is based on the FSA(Frequency Scaling Algorithm) for high resolution image formation of the Spotlight SAR. Phase errors produce the degradation of SAR image quality such as loss of resolution, geometric distortion, loss of contrast, spurious targets, and decrease in SNR. To resolve this problem, this paper presents method for correction of phase errors using the PGA(Phase Gradient Algorithm) in connection with the FSA. Several results of the phase errors correction are presented for Spotlight SAR rawdata.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.183-194
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• 2011

Synthetic aperture radar (SAR) is widely used because of high resolution imaging capability in all weather and day/night condition. In this paper development of Spotlight SAR simulator is proposed for image quality analysis. Proposed SAR simulator is based on the SAR system design parameters so that SAR image performance can be expected which is essential throughout the full system development procedure from the initial concept design stage to the final in-flight calibration and validation stage. The raw data of ideal point target is first generated by taking account of the flight and imaging geometry and the various SAR system design parameters, and the Spotlight image formation algorithm is implemented in order to obtain the point target response. Finally the image quality of the generated raw data is analyzed in terms of spatial resolution, peak to sidelobe ratio and integrated sidelobe ratio.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.857-860
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• 2005

Several algorithms have been developed for the data processing of spotlight synthetic aperture radar (SAR). In particular, the range migration algorithm (RMA) does not assume that illuminating wavefronts are planar. Also, a high resolution image can be obtained by the RMA. This paper introduces an extension of the original RMA to enable a more efficient airborne SAR data processing. We consider more general motion and scene than the original RMA. The presented formulation is analyzed by using the principle of the stationary phase. Finally, the extended algorithm is tested with numerical simulations using the pulsed spotlight SAR.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.165-166
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• 2008

Bistatic spotlight synthetic aperture radar(BSSAR) with single track configuration uses the transmitter and the receiver which travel along the single track such as the leader-follower. For the BSSAR imaging, we modify the range migration algorithm. In time domain, we make the monostatic SAR using shifting of path, Then, in frequency domain, we compensate the separated distance between the scene center and the flight path using the principle of the stationary phase (PSP).

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.937-938
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• 2008

Spotlight system has been made use of art works on stage such as musical and performance etc. Currently, spotlight is controlled manually through the planned path in advance. Therefore, automatic control system is necessary for manipulating spotlight on stage. In this paper, we propose the system that detects to track the multiple objects and classifies those objects, also selects an object of those ones. The proposed method can be applied to the interactive stage spotlighting system(ISSS).

• The Magazine of the IEIE
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• v.12 no.3
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• pp.4-7
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• 1985

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.10
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• pp.921-932
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• 2016

In this paper, a modified FSA(Frequency Scaling Algorithm) is proposed for KOMPSAT-5 high-resolution SAR image generation. In order to enhance performance of azimuth compression, degraded in sub-aperture processing due to the imperfect geometric parameter of data acquisition, the full-aperture signal processing algorithm is designed based on the exact time-frequency analysis. In addition, an azimuth scaling function is newly devised to make the full-aperture processing algorithm suitable for KOMPSAT-5 sliding-spotlight mode. Different from the previous sub-aperture FSA schemes, the suggested technique could accommodate the merit of unified signal processing structure regardless of operational modes of KOMPSAT-5. Through the point target simulation, it is verified that the suggested algorithm provides superior performance of azimuth compression over the existing full-aperture processing methods. The experimental results using real data acquired by KOMPSAT-5 are also given to demonstrate the effectiveness of our scheme as well.