• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.3
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• pp.291-297
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• 2016

Direct georeferencing has become widespread in the field of digital aerial photogrammetry; as a result, the boresight calibration has become an essential component of the procedure to calculating exterior orientation parameters of aerial photographs accurately. During this procedure, a reference is used for the height of the geoid model, and the calibration results can appear different depending on the geoid model. The exterior orientation parameters calculated through direct georeferencing during boresight calibration may have varied values according to the corresponding geoid model. With that in mind, the effects of the geoid model on the boresight calibration were analyzed through three different cases. The geoid models used in the experiments were EGM96, EGM08, and KNGeoid14, and, through boresight calibration, the datum shift and boresight angle for each model was computed. After calculating the exterior orientation of each case, the GCP (Ground Control Point) was verified using the DPW (Digital Photogrammetry Workstation). In each case, results in the boresight calibration acquired through the geoid model demonstrated a difference in the Z datum, the exterior orientation heights Z, and the rotation Ω and Φ. After utilizing the DPW in each case and comparing it to the GCP, the difference in accuracy in accordance with the geoid model was found to be within 3cm, and it was concluded that the geoid model did not have a significant impact on boresight calibration.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.56-63
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• 2005

The radome boresight error degrades the microwave seeker ability and the missile guidance performance. It increases the miss distance, also. This paper propose a method of radome boresight error measurement and compensation. The compensation method consist of radome analysis and radome compensation. In the radome analysis stage, we can know that the electromagnetic characteristics distorted by radome. In the compensation stage, the look-up table is built and used for compensation. The test uses a FMS(Flight motion simulator) and adjusts the FMS setup error for more accuracy. The result shows that not using an elaborate radome measurement equipment, the radome boresight error is well compensated easily.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.4_1
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• pp.293-298
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• 2014

Recently, the direct georeferencing has been becoming a common method in the aerial photogrammetry. As this direct georeferencing method using converged sensor of the digital photogrammetry camera and GPS(Global Positioning System)/INS(Inertial navaigation System), more rapid and accurate aerial photogrammetry has improved following advanced performance in photogrammetry. Since the accuracy of EO parameters from the direct georeferencing is determined by GPS/INS accuracy, it is significant to calculate the exact attitude information using values of INS rotations. For following calculations, the misalignment, such as INS rotation and the gap of GPS/INS, has to be decided. Because the number of ground control points are used for tirangulation and boresight calibration, those results should be different according to array and location of ground control points. In the study, those location and array of ground control points were tested to be used boresight calibration. As a result, there is no significant change of misalignment and exterior orienation parameters in the case when ground control points were at all course. On the contrarily, the difference has been shown in the case of no ground control point at course.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2003.10a
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• pp.129-134
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• 2003

Mobile Mapping System needs system calibration of multi sensors. System calibration is defined as determination of spatial and rotational offsets between the sensors. Especially, EO parameters of GPS/INS require knowledge of the calibration to camera frame. The calibration parameters must be determined with the highest achievable accuracy in order to get 3D coordinate points in stereo CCD images. This study applies Boresight calibration for the calibration between GPS/INS and camera, and estimates the Performance of the calibration.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.745-751
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• 2013

In naval gun firing, firing accuracy comes from the combination of each component's accuracy in CFCS (Command and Fire Control System) like tracking sensors and gun. Generally, battery alignment is done to correct the error between gun and tracking sensor by using boresight telescope on harbor and sea. But normally, the battery alignment can compensate only the static alignment error and ignore dynamic alignment error which is caused by own ship movement. There was no research on this dynamic alignment error until now. We propose a new way to analyze dynamic arrangement error by using image of boresight telescope. In case of the dynamic alignment error was due to time delay of own ship attitude information, we propose the way to compensate it.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.3
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• pp.379-385
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• 2018

Boresight process is to match the misalignment between PNU(Position Navigation Unit) and the reference axis of K-MLRS cage. It is important process to ensure accuracy of K-MLRS. When PNU is removed from cage in the previous alignment procedure, there is a misalignment angle with cage of K-MLRS during reassembly process. Therefore, boresight process is always need to align reference axes between PNU and K-MLRS cage. However, this study has proposed the case alignment process that it enable to correspond to reference axes between ISA (Inertial Sensor Assembly) block and PNU case. So, improved alignment procedure enables to install PNU in the reassembly process without additional boresight process.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.145-149
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• 2006

모바일 맹핑시스템에 장착되어 있는 카메라와 INS의 물리적 관계 (두 좌표축 간의 거리(lever-arm) 와 각도(boresight) 캘리브레이션은 카메라 영상의 지리적 정보를 생성하기 위해 필요로 한다. 이 목적을 위해 기존연구는 카메라 캘리브레이션을 통하여 이 물리적 관계를 추정하고 있다. 카메라 캘리브레이션은 3차원 좌표가 할당된 타겟을 이용하여 움직이는 카메라의 렌즈 왜곡과 내/외부 표정 계산하는 것이다. 이 추정에서, 저가의 INS의 초기상태인 자세, 각도는 사용자의 측량에 의해 결정이 된다. 만약 정교한 측량이 없을 경우, 카메라 영상의 지리적 정보는 잘못된 정보를 제공 할 것이다. 정교한 측량의 어려움을 피하기 위해, 본 논문은 카메라와 초기상태 정보가 없는 INS간의 물리적 관계를 위한 수학적 모델을 설계하였다. 시스템에 장착된 카메라와 INS의 초기 기준 좌표계의 관계는 lever-arm과 boresight을 이용한 좌표축 변환으로 정의 될 수 있으며, 이 시스템이 이동 후, 카메라 초기 기준 좌표계에서 INS의 위치는 두 개의 벡터 경로로 정의 될 수 있다. 이 두 벡터 경로는 카메라와 INS의 상대 외부표정의 관계를 이용하여 계산된 벡터들의 조합으로 정의된다. 본 논문은 여러 쌍의 경로로부터 lever-arm과 boresight을 추정하였다.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.546-551
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• 2023

In this study, a beam steering measurement system was developed to perform functions such as far-field beam steering and near-field beam focusing for TX/RX modes in the near file of the AESA radar. The beam steering measurement system consists of a spherical near-field scanner, an antenna positioner, a near-field controller, a network analyzer, a radar control system, a verification radar, a simulated radio, and an AESA radar. Using the developed system, the characteristics of TX/RX patterns before and after installation of radome to AESA radar were measured, and the beam pattern was analyzed through conversion to far field-after near-field measurement.The boresight error of the radar antenna device was measured, and it was confirmed that the main lobes were formed the same before and after the simulated radar dome was mounted.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.158.5-158
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• 2001

Monopulse active homing radar requires velocity and angle information of target to track fast moving target. Target velocity can be estimated by measuring the frequency shift between transmitted and received frequencies. Angle information is obtained by measuring boresight error. Measurement of doppler frequency component in received signal is done through FFT analysis and interpolation algorithm for fine tuning. Boresight errors in azimuth and elevation axes are proportional to the power of each difference channel relative to sum channel. The target signal power in difference channel is estimated more precisely by measuring the power of FFT result cell of maximum ...

• Journal of computational fluids engineering
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• v.20 no.1
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• pp.99-104
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• 2015

Aero-optic phenomena cause the image position displacement on an imaging plane of the airborne optical/IR systems. Particularly, the aero-optic boresight error(BSE) is important factor for homing, positioning and aiming applications of hypersonic flight interceptor missile. In this paper, an estimating method of aero-optic BSE for a hypersonic flight vehicle is studied. A ray tracing method and a transform method of refractive index fields from flow density fields are combined with computational fluid dynamics(CFD) method.