• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.2
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• pp.191-198
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• 2013

Geo-pointing is a function that maintains LOS(Line of Sight) to a stationary ground target by controlling azimuth and elevation angles of a EOS(Electro-Optical System) which are calculated from aircraft navigation data and target coordinates. In design and implementation of the geo-pointing, a transmission time delay between GPS/INS and EOS is a major degradation factor of the geo-pointing performance when the aircraft is rapidly maneuvered especially. In this paper, a kalman filter is designed to compensate the transmission time delay of aircraft navigation data. Simulation and test results show that the geo-pointing performance is enhanced by the proposed compensation technique.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.355-361
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• 2005

3차원 자료의 필요에 발맞추어 3차원 좌표를 직접적으로 획득할 수 있는 LIDAR 시스템이 등장하게 되었다 항공 LIDAR 시스템은 항공기, GPS, INS, Laser Scanner가 통합된 시스템으로 항공기에서 발사된 Laser의 반사파를 이용하여 거리와 그 때의 항공기의 자세, 위치를 통합하여 직접적인 3차원 포인트 자료를 획득할 수 있다. LiDAR 데이터는 지형, 건물, 식생 등의 지면위에 있는 모든 객체에 대한 3차원 자료와 영상자료를 함께 제공하고 있다. 이러한 LIDAR 자료로부터 DEM, DTM 등의 지형 정보와 식목, 건물 등 지물정보를 추출하는 연구가 활발하게 이루어지고 있다. 본 연구에서는 지형을 추출하는데 사용할 수 있는 몇 가지 필터링기법을 선정하여 국내의 다양한 지모, 지물에 적용하고 그 정확도를 평가해 보았다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.319-326
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• 2006

All around tile world there has been great human and economical damage continuously by disasters like the earthquakes and storms(Tsunami) in eastern asia which recently occurred, and like the New Orleams hurricane in USA. The situation is our countries damage from natural disasters due to heavy snow, storms, forest fires have been increasing In this research we obtained GSIS data of the 05' Yang-yang forest fire disaster area using multi-sensors like airborne laser data, GPS/INS, aerial photograph surveying. In result we produced digital topographical maps, digital elevation models, digital external models, digital images, infrared images. By, analyzing and comparing with past aerial photography we obtained the exact damage area, amount of damage, estimated tile areas where a landslide might occur, and we analyzed vegetations amount of damage and possibility of recovery.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.193-198
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• 2006

최근의 동남아시아 발생한 지진해일(쓰나미)과 미국 뉴올리언즈 지역의 허리케인으로 등의 재난으로 인해 막대한 인명과 경제적 피해가 전 세계적으로 빈번히 발생하고 있다. 우리나라도 폭설과 태풍, 산불로 인한 피해가 해마다 증가하고 있는 실정이다. 본 연구에서는 '05년 양양지역의 대규모 산불재해지역을 중심으로 항공레이저측량, GPS/INS항공사진측량 등의 다중센서를 이용하여 GSIS자료를 취득하였다 이를 통해 수치지형도, 수치고도모형, 수치외관모형, 디지털 영상, 근적외선 영상을 처리하였으며, 과거 항공사진자료와의 비교 분석을 통해 정확한 피해면적과 피해량, 향후 산사태가 발생할 수 있는 지역 예측 및 식생에 대한 피해정도와 회생가능성을 분석하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.50-57
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• 2008

A telemetry ground station has a highly directional, parabolic tracking antenna to receive a weak telemetry signal from a target at a distance. The tracking antenna with narrow beam-width normally uses the auto-track method for the target tracking. This paper presents several issues in the auto-track method and introduces a new tracking method using Self-Slaving technique. Self-Slaving means that the tracking antenna is slaved to not data measured by RADAR but GPS/INS informations received by the telemetry system for pointing. The Self-Slaving method shows good performance in comparison with auto-track method.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.5
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• pp.623-629
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• 2012

In this paper, we analysis the performance of position estimation when adopting Dynamic TDMA(DTDMA) in JTIDS RelNav. JTIDS RelNav is widely understood as a new navigation solution possibly capable to support or take cover of the role of conventional systems including INS or GPS no matter if they are working well or not. By maximizing the efficiency of radio resource management in MAC(Medium Access Control) layer we enhance the system performance without any replacement of hardware.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.3
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• pp.249-255
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• 2011

The free-stereo mosaics image without GPS/INS and ground control data can be generated by using relative orientation parameters on the 3D model coordinate system. Its origin is located in one reference frame image. A 3D coordinate calculated by conjugate points on the free-stereo mosaic images is represented on the 3D model coordinate system. For determining 3D coordinate on the 3D absolute coordinate system utilizing conjugate points on the free-stereo mosaic images, transformation methodology is required for transforming 3D model coordinate into 3D absolute coordinate. Generally, the 3D similarity transformation is used for transforming each other 3D coordinates. Error of 3D model coordinates used in the free-stereo mosaic images is non-linearly increased according to distance from 3D model coordinate and origin point. For this reason, 3D model coordinates used in the free-stereo mosaic images are difficult to transform into 3D absolute coordinates by using linear transformation. Therefore, methodology for transforming nonlinear 3D model coordinate into 3D absolute coordinate is needed. Also methodology for resampling the free-stereo mosaic image to the geo-stereo mosaic image is needed for overlapping digital map on absolute coordinate and stereo mosaic images. In this paper, we propose a 3D non-linear transformation for converting 3D model coordinate in the free-stereo mosaic image to 3D absolute coordinate, and a 2D non-linear transformation based on 3D non-linear transformation converting the free-stereo mosaic image to the geo-stereo mosaic image.

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.593-599
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• 2013

In this paper, the GPS cycle-slip detection for carrier-phase based positioning of land vehicle is presented. For the carrier phase based positioning, cycle-slip detection is necessary to get the reliability of positioning result. There exists many cycle-slip detection algorithms, but we detect the cycle-slip by using the monitoring value which is defined as residual between the carrier phase measurement and estimated value from low-cost inertial sensor. To achieve goal of paper, low-cost cycle-slip detection system, permissible specification region of inertial sensor is derived. By using the result of permissible region, appropriate inertial sensor of cycle-slip detection can be decided, proper cost and proper specification. To verify the result of this paper, we conduct the rate table test. As a result, required cycle-slip detection performance is satisfied conservatively.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.3
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• pp.463-471
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• 2020

Recently, various tries to apply ROV (Remotely Operated Vehicle) into underwater are being developed. However, due to underwater environment uniqueness, the additional problem must be taken into account when designing an ROV for the inspection of the underwater structure. This is because a GPS-based information method cannot be applied, and the obtainable image is also dependent on the turbidity. Also, it is necessary to be able to satisfy waterproof and operating speeds in consideration of most practical application environments. This paper describes the design results of the ROV system for underwater structure inspection considering the above problems. The designed system applied INS / DVL for location recognition and was configured to support 3D mapping and stereo camera-based image information using sonar depending on visibility. To satisfy the waterproof, a pressure vessel using a composite material was applied. And over-actuated system using eight thrusters to maintain a stable posture and operating speed was applied also. The designed system was verified by structural analysis and flow analysis also.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1121-1126
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• 2017

Various studies such as INS(: Inertial Navigation System) are conducting to estimate the position of UAV, because the GPS information of UAV is at risk like the GPS jamming. The position estimation using DoA and RTT are used to apply many radar systems, and that process can be applied in datalink of UAV. The general monopulse feed in UAV datalink is Multi-horn, because of the wide BW(: Band Width) and frequency range. And it needs wide SNR range of tracking because of the limited transmit power of airborne unit. The estimation error of position increase at low SNR, and the DoA is valid in only 3dB beam width but high SNR causes false of mainlobe detection because of large sidelobe. In this paper, We propose the method to achieve higher accuracy of DoA estimation on low SNR and review some idea that able to detect mainlobe.