• Title/Summary/Keyword: synchronization & Integration

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Performance Characteristics of Time Delay and Integration(TDI) Satellite Imager for Altitude Change and Line-Of-Sight Tilt over Spherical Earth Surface

  • Cho, Young-Min
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.216-221
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    • 2002
  • A spherical Earth surface is used fur realistic analysis of the geometrical performance characteristics about the variation of satellite altitude and 2-dimensional line-of-sight(LOS) tilt angle in a satellite imager using Time Delay and Integration(TDI) technique with fixed integration time. In the spherical Earth surface model TDI synchronization using LOS tilt is investigated as a solution to compensate geometric performance degradation due to altitude decrease. This result can be used fur a TDI CCD imager with variable integration time in a certain as well.

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Study on the Synchronization of Time Delay and Integration against Osculating Altitude Variation in Satellite Imager (순간 고도 변화에 대한 위성 영상 기기의 Time Delay and Integration 일치 연구)

  • Cho Young-Min;Kim Hae-Dong
    • Korean Journal of Remote Sensing
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    • v.20 no.4
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    • pp.227-234
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    • 2004
  • The synchronization of Time Delay and Integration (TDI) against the temporal variation of osculating altitude in the operation of high resolution satellite imager was studied. The characteristics of osculating altitude variation was analyzed and its impact on the performance of TDI imger was also investigated. A practical ]me rate control method was proposed to compensate instantaneous TDI mismatch due to the osculating altitude variation, so that geometrical performance enhancement was achieved by the proposed method. This study is applicable to real satellite operation and can be useful for satellite image quality enhancement.

Study on the Synchronization of Time Delay and Integration of Satellite Imager for Satellite Altitude Variation (위성 고도 변화에 대한 위성 영상 기기의 Time Delay and Integration 일치 연구)

  • 조영민;김해동
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2004.03a
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    • pp.235-240
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    • 2004
  • Time Delay and Integration (TDI) 기법을 사용하는 고해상도 위성 영상기에 있어서 실제 위성 운영시 발생하는 위성 고도의 순간적 변화에 대한 TDI 일치를 연구하였다. 시간에 따라 변하는 순간 고도의 특성을 분석하였고 순간 고도 변화가 TDI 불일치를 초래하여 위성 영상 기기의 성능에 미치는 영향을 분석하였다. TDI 시간 지연을 조절하여 실제 위성 운영에서 순간적으로 발생하는 TDI 불일치를 보정하고 성능을 향상시킬 수 있는 가능성을 연구하였다. 본 연구 결과는 위성 영상 품질 향상에 활용될 수 있다.

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A Novel GPS Initial Synchronization Scheme with Decomposed Differential Matched Filter (분해형 차분 정합필터를 갖는 새로운 GPS 초기동기 방식)

  • Park, Sang-Hyun;Lee, Sang-Jeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.2
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    • pp.185-192
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    • 2002
  • A novel GPS initial synchronization scheme with low hardware complexity is proposed. The proposed method has the decomposed differential matched filter, which consists of 25% multiplier and adder of the conventional matched filter. This paper presents the generalized mean acquisition time of initial synchronization scheme with multiple correlator. It is shown that the proposed method, in spite of its low hardware complexity, has the equal performance to the conventional method. The performance of the proposed method is verified through the simulation test by the GPS simulator. It is shown that the proposed method prevents the squaring loss of non-coherent integration.

Integration and Synchronization of Multi Sensors for Mobile Mapping System (모바일 매핑시스템을 위한 멀티 센서 통합 및 동기화 구현 방안 연구)

  • Park, Young-Moo;Lee, Jong-Ki;Sung, Jeong-Gon;Kim, Byung-Guk
    • Journal of Korea Spatial Information System Society
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    • v.6 no.1 s.11
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    • pp.51-58
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    • 2004
  • Mobile Mapping System is an effective wav to obtain position and image using vehicle equipped with GPS(Global Positioning System), IMU(Inertial Measurement Unit), and CCD camera. It have been used various fields of load facility management, map upgrade and etc. It is difficult to upgrade Mobile Mopping System which is developed from abroad and add other sensors because we don't know the way to integrate and synchronize multi-sensors. In this paper, we present the effective way of the integration and synchronization method for multi sensors we designed and manufactured Synchronization equipment by considering sensors of laser, odometer and etc.

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A Study on the Principles of Military Operations Coincident with Modern War (현대전 양상에 부합된 군사작전 원칙에 관한 연구)

  • Lee, Kang-Un;Choi, Sung-Soo
    • Journal of National Security and Military Science
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    • s.7
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    • pp.129-154
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    • 2009
  • The principles of military operations(principles of war) are the fundamental principles ruling warfighting that made based on the experiences of wars from the time of ancient Greeks to the World War II. Recent wars such as Iraq War showed us the change of environment of war and the style of waging a war. It is believed that future war will be executed with the style of Rapid Deceive Operations, Effect Based Operations, Network Centric Operations. Therefor the principles of war which we use should be reconsidered whether it is useful or not in future warfare. By considering the present principles of operation which are using in many countries and analysing the style of waging future war, we suggest new principles of operations : principle of gravity, principle of mass and dispersal, principle of disturbance, principle of speed, principle of paralysis, principle of synchronization and integration, principle of leadership, and principle of information.

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Efficient Frame Synchronization Detector and Low Complexity Automatic Gain Controller for DVB-S2 (효율적인 디지털 위성 방송 프레임 동기 검출 회로 및 낮은 복잡도의 자동 이득 제어 회로)

  • Choi, Jin-Kyu;Sunwoo, Myung-Hoon;Kim, Pan-Soo;Chang, Dae-Ig
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.2
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    • pp.31-37
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    • 2009
  • This paper presents an efficient frame synchronization strategy with the identification of modulation type for Digital Video Broadcasting-Satellite second generation (DVB-S2). To detect the Start Of Frame (SOF) and identify a modulation mode at low SNR, we propose a new correlator structure and a low complexity Automatic Gain Controller (AGC). The proposed frame synchronization architecture can reduce about 93% multipliers and 89% adders compared with the direct implementation of the Differential - Generalized Post Detection Integration (D-GPDI) algorithm which is very complex and the proposed a low complexity AGC consists of only 5 multipliers and 3 adders. The proposed architecture has been thoroughly verified on the Xilinx Virtex II FPGA board.

Principles of War under the NCW environment (네트워크 중심전(NCW)하에서의 군사작전 원칙)

  • Choi, Seong-Su
    • Journal of National Security and Military Science
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    • s.8
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    • pp.311-350
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    • 2010
  • War has been existing with human history. There seems to be two approaches of war study. One is to deter war among politicians, the other is to get victory in a war among soldiers. Many scholars and soldiers tried to find out the way of victory at war, that is, the major factors of victory at war. They found out some factors that dominate the victory of war through numerous experiences of war, and we call it 'principles of war'. The principles of war which we are using has been shaped during past three centuries. But, nowadays rapid change in the environment of war has brought the change of features of warfare and method of waging war. NCW may be the most typical example of new environment of war. The Iraque War may be the most recent modem war performed under the NCW environment. And the Iraque War brought up the need of new principles of war adaptable to the NCW environment. This article is focusing on new principles of war that comprehends future wars. I suggest that some principles of war which we are using should be supplemented to be understood its own conception, and new principles are needed such as principle of paralysis, principle of synchronization & Integration.

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A Development of Attitude GPS/INS Integration System (자세 측정용 GPS/INS통합 시스템 개발)

  • Oh, Chun-Gyun;Lee, Jae-Ho;Seo, Hung-Seok;Sung, Tae-Kyung
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.1984-1986
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    • 2001
  • In order to provided continuous solutions, latest developing navigation systems tend to integrate GPS receiver with INS or DR. Using the GPS carrier-phase measurements, an attitude GPS receiver with three antennas obtain the 3-dimensional attitude such as roll, pitch, and heading as well as position and velocity. With these angle measurements, in the attitude GPS/INS integrated system, attitude or gyro errors can be directly compensated. In this paper, we develop an integrated navigation system that combines attitude GPS receiver with INS. The performance of real-time integrated navigation system is determined by not only the implements of integration filter but also the synchronization of measurements. To meet these real-time requirements, the navigation software is implemented in multi-tasking structure in this paper. We also employ time-synchronization technique in the multi-sensor fusion. Experimental results show that the performance of the attitude GPS/INS integrated system is consistent even when cycle-slip occurs in carrier-phase measurements.

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