• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.8
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• pp.661-669
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• 2017

This paper describes an MMTI(Maritime Moving Target Indicator) for periscope detection in airborne radar. Firstly, we analyze the characteristics of sea clutter, sea targets. Secondly, we study the differences between GMTI(Ground Moving Target Indicator) and MMTI. This paper proposes an optimal MMTI operating environment and method. We also suggest a signal processing algorithm using STAP(Space-Time Adaptive Processing) for detecting small RCS target moving low speed. The detection probability for moving target with MDV(Minimum Detectable Velocity) is simulated under various RCS and multi-channel system. Finally, we analyze the major performance for range, velocity and azimuth accuracy.

• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.1-7
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• 2009

Airborne electromagnetics (AEM) is a useful tool for investigating volcanic structures because it can survey large and inaccessible areas. Disadvantages include lower accuracy and limited depth of investigation. The Grounded Electrical Source Airborne Transient Electromagnetic(GREATEM)survey system was developed to increase the depth of investigation possible using AEM. The method was tested in a survey at Mount Bandai in north-eastern Japan. Mount Bandai is an andesitic stratovolcano that rises 1819m above sea level. An eruption in July 1888 left a hoof-shaped collapsed wall in its northern crater and avalanche debris at its base. Previous surveys of Mount Bandai allow for comparisons of data on its structure and collapse mechanism as obtained by GREATEM and other geophysical methods. The results show resistive structures in recent volcanic cones and conductive structures in the collapsed-crater area. Conductive areas around the collapsed wall correspond to an alteration zone resulting from hydrothermal activity, supporting the contention that a major cause of the collapse associated with the 1888 eruption was hydrothermal alteration that structurally weakened the interior of the volcanic edifice.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.267-272
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• 2005

최근 항공레이저스캐닝(ALS)은 높은 정확도와 경제성을 이유로 지형정보를 획득하는 탁월한 수단으로 주목받고 있다. ALS에 의해 수집되는 고도자료는 DSM, DEM 제작에 유용하게 이용된다. ALS는 고도자료 이외에 지표면의 물질적 특성을 나타내는 반사강도를 획득한다. 그러나 반사강도는 노이즈로 인해 널리 이용되지 못하고 있으며, 노이즈의 주원인은 반사각으로 알려져 있다. 따라서 본 연구는 센서 위치정보와 ALS 고도자료를 이용하여 반사각을 이용하여 반사강도를 보정하는 방법을 제안하였다 여기에는 ${\theta}$의 각도로 입사한 레이저의 강도는 수직으로 입사한 레이저의 강도보다 $sin{\theta}$만큼 감소한다는 물리학적 원리가 이용되었다 반사각은 지표면과 레이저가 이루는 각으로, 센서와 측정점 사이의 각과 지표면의 경사각의 두 단계로 나누었다. 방법의 적합 여부를 확인하기 위해 적외선 영역에서 분리도가 잘 이루어지는 아스팔트, 휴경지(토양), 콘크리트, 수목의 네 가지 검증영역을 선정하여 보정된 반사강도와 보정 전의 반사강도를 비교하였다. 모든 영역에서 반사강도가 증가하였으며 특히 콘크리트와 수목에서의 증가가 두드러졌다. 보정을 통해 네 영역에서 반사강도의 분리도가 향상됨을 물론 그 크기가 '아스팔트<토양<콘크리트<수목'으로 나타나는 이론적인 경향과 유사함을 확인할 수 있다.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.475-482
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• 2023

Synthetic Aperture Radar (SAR), which provides images of targets using radio signals, enables monitoring at all times regardless of weather conditions. In this paper, the SAR system was installed on the test aircraft to collect SAR raw data on the ground and the sea, and the results of image formation using the backprojection algorithm were presented.

• Journal of Advanced Navigation Technology
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• v.10 no.2
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• pp.173-180
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• 2006

An airborne radar is an essential aviation electronic system of the aircraft to perform various missions in all weather environments. This paper presents the design, development, and test results of the multi-mode pulsed Doppler radar system test model for helicopter-borne flight test. This radar system consists of 4 LRU units, which include ANTU(Antenna Unit), TRU(Tx Rx Unit), RSDU(Radar Signal & Data Processing Unit) and DISU(Display Unit). The developed technologies include the TACCAR processor, planar array antenna, TWTA transmitter, coherent I/Q detector, digital pulse compression, DSP based Doppler FFT filtering, adaptive CFAR, IMU, and tracking capability. The design performance of the developed radar system is verified through various helicopter-borne field tests including MTD (Moving Target Detector) capability for the Doppler compensation due to the moving platform motion.

• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.801-810
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• 2018

Ship monitoring using satellite synthetic aperture radar (SAR) images consists of ship detection, ship discrimination, and ship classification. A large number of methods have been proposed to improve the detection and discrimination capabilities, while only a few studies exist for ship classification. Thus, many studies for the ship classification are needed to construct ship monitoring system having high performance. Note that constructing database (DB), which contains both SAR images and labels of various ships, is important for research on the ship classification. In the airborne SAR classification, many methods have been developed using moving and stationary target acquisition and recognition (MSTAR) DB. However, there has been no publicly available DB for research on the ship classification using satellite SAR images. Recently, Shanghai Key Laboratory has constructed OpenSARShip DB using both SAR images of various ships generated from Sentinel-1 satellite of European Space Agency (ESA) and automatic identification system (AIS) information. Thus, the applicability of OpenSARShip DB for ship classification should be investigated by using the concepts of airborne SAR classification which have shown high performances. In this study, ship classification using satellite SAR images are conducted by applying the concepts of airborne SAR classification to OpenSARShip DB, and then the applicability of OpenSARShip DB is investigated by analyzing the classification performances.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.281-290
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• 2021

For successful operations of an airborne Active Electronically-Scanned Array (AESA) radar, which has various advantages over traditional radar systems, accurate and robust navigation is critical. This paper discusses a study on the performance analysis of an integrated navigation based on the Embedded GPS/INS (EGI) system for an aircraft equipped with an AESA radar. The models for generating the inputs for the GPS/IMU are developed. A navigation filter for a loosely-coupled GPS/IMU system is constructed. Overall navigation performance assessment procedure using a six degree of freedom aircraft simulator - along with the GPS/IMU models and the navigation filter - is introduced. The steps of the performance analysis procedure are explained using a comprehensive case study.

• Journal of Advanced Navigation Technology
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• v.27 no.4
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• pp.429-435
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• 2023

The increasing complexity of avionics systems has emphasized the portability and reusability of software components. In this paper, a structural design method for IOSS (Input Output Service Segment) and TSS (Transport Service Segment) complying with the FACE (The Future Airborne Capability Environment) standard in the VxWorks 653 operating environment that satisfies ARINC 653 requirements is described. IOSS and TSS operate independently in different partitions to minimize time/space separation and the influence of other software, and to increase portability and reusability, strategy patterns among design patterns are applied. In addition, IOSS provides external interface service by applying distributed IO service structure, and among external interfaces, the ARINC 664 P7 interface of FACE-compliant equipment is placed in TSS to optimize the data movement path.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.3
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• pp.253-259
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• 2007

Standard design and suitable environmental test method should be applied to increase the reliability of UAV flight control systems. UAV flight control systems under development domestically have enough capabilities for complicated missions. However, most low cost systems are not designed with concepts of compatibility, adaptability, and environmental compliance. This paper explains ATR(Air Transport Rack) standard that is widely used on aircraft. The paper presents a design uses commercial off-the-shelf parts. The paper also presents various environmental standards for airborne equipments, including U.S. military specifications. The developed FCS was tested under these specifications. The paper shows the test procedures and results.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.15-26
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• 2004

The calibration for systematic error in LiDAR is crucial for the accuracy of airborne laser scanning. The main error is the misalignment of platforms between INS(Inertial Navigation System) and Laser scanner For planimetrical calibration of LiDAR, the building is good feature which has great changes in height and continuous flat area in the top. The planimetry error(pitch, roll) is corrected by adjustment of height which is calculated from comparing ground control points(GCP) of building to laser scanning data. We can know scale correction of laser range by the comparison of LiDAR data and GCP is arranged at the end of scan angle where maximize the height error. The area for scale calibration have to be large flat and have almost same elevation. At 1000m for average flying height, The Accuracy of laser scanning data using LiDAR is within 110cm in height and ${\pm}$50cm in planmetry so we can use laser scanning data for generating 3D terrain surface, expecically digital surface model(DSM) which is difficult to measure by aerial photogrammetry in forest, coast, urban area of high buildings