• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.259-264
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• 2006

It is well known that the uncertainty of the covariance parameters of the process noise (Q) and the observation errors (R) has a significant impact on Kalman filtering performance. Q and R influence the weight that the filter applies between the existing process information and the latest measurements. Errors in any of them may result in the filter being suboptimal or even cause it to diverge. The conventional way of determining Q and R requires good a priori knowledge of the process noises and measurement errors, which normally comes from intensive empirical analysis. Many adaptive methods have been developed to overcome the conventional Kalman filter's limitations. Starting from covariance matching principles, an innovative adaptive process noise scaling algorithm has been proposed in this paper. Without artificial or empirical parameters to be set, the proposed adaptive mechanism drives the filter autonomously to the optimal mode. The proposed algorithm has been tested using road test data, showing significant improvements to filtering performance.

• 한국농공학회논문집
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• 제52권6호
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• pp.9-17
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• 2010

In this paper, an automatic cruise system of unmanned boat was developed for surveying water depth in reservoir using GIS (geographic information system)-GPS (global positioning system) Technologies. the automatic cruise system consisted of an automatic path generation program (APGP) and an automatic boat control program (ABCP). A grid processing method with $3{\times}3$ roving window in GIS function was used to develop the APGP. For development of the ABCP, GPS and its coordinate calculation technique were introduced. The developed system was tested to verify the applicability for a sample reservoir, Misan reservoir located on Ansan city of Kyunggi province. From the test results, this study found the APGP generated cruise path automatically according to input condition on grid size of 5 m, 10 m, and 20 m, as well as, the ABCP also tracked well the cruise paths with high position accuracy. Another verification result on surveying time for 20 ha of water area also showed that the new system could survey water depth of reservoir quickly, including very high quality of spatial resolution.

• 한국측량학회지
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• 제8권1호
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• pp.23-30
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• 1990

본 연구는 조합망 조정에 있어서 승여관측수가 정도에 미치는 영향을 파악하기 위하여 승여관측수를 변화시켜서 망을 조정한 것이다. 또한 수평위치 결정에 있어서 어떤 방법이 가장 효용성이 있는지를 제시하기 위하여 승여관측수에 따른 정밀도를 분석하였다. 본 연구에서 실시한 조합망의 조정에 있어서 평균제곱근 오차는 삼변측량에 비하여 장축에서 약 78∼82%, 단축에서 약 48∼60%, 삼각측량에 비하여 장축에서 약 84∼87%, 단축에서 약 29∼45% 감소되었고, 승여관측수와 정밀도와의 사이에는 Y=464.71429X＋13517.57143의 함수관계가 성립한다. 그러나 승여관측수의 증가가 정밀도를 향상시키므로 최적의 승여관측수의 결정은 경제적인 측면에서 매우 중요한 과제이므로 앞으로의 연구과제라 생각된다.

• 한국측량학회지
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• 제8권1호
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• pp.15-22
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• 1990

본 연구에서는 근접사진측량에 의하여 대상물의 전면에 대한 동시 정밀 3차원 위치해석의 가능성을 제시하는데 목적을 두었으며, 이를 위하여 network의 imaging geometry, 기준점 배치 등 기하학적 배치를 고려하여 대상물의 전면을 피복하는 스트립과 블럭을 형성, 번들조정기법으로 해석을 시도하였다. 그 결과, 양호한 정학도로 전면해석의 가능성을 입증할 수 있었고, network의 기하학적 배치에 따른 정확도의 특성을 도출하였다. 또한 국부적으로 배치된 소수의 기준점으로도 소기의 정학도를 얻을 수 있었으므로 전면해석을 위한 기준점 측량의 난제를 크게 줄일 수 있을 것으로 사료된다.

• 한국측량학회지
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• 제25권4호
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• pp.299-307
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• 2007

본 연구는 GPS 상시관측점을 이용한 간접수준측량의 활성화를 위한 기반 작업인 GPS 상시관측점의 실용표고 계산에 관한 것이다. 직접수준측량과 GPS 간접수준측량, 그리고 중력측량 결과들을 조합하여 GPS 상시관측점의 안테나 참조점에 대한 표고좌표를 정밀하게 계산하는 방법을 제시하였으며, 우리나라 수준점 성과의 정밀도와 측량작업의 정밀도에 근거하여 계산된 표고좌표에 대한 기대오차를 예측하고, 실제 측정결과의 정확도를 이용하여 검정함으로써, 계산된 표고좌표에 대한 신뢰도를 분석하였다.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.883-890
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• 2021

In this study, joint analysis was conducted on the rock slope by aerial surveying using UAV. Aerial photos were taken using UAV to measure the directionality of the rock slope exposed to the site, and the directionality of the joint was analyzed using the photographed photos. UAV photography was taken under conditions of 90% overlap and an altitude of 50m. The photographing path was measured in the horizontal, vertical, and oblique directions based on the slope, and the joint characteristics were analyzed. Aerial surveying research on the joint directionality analysis of rock slopes is still incomplete, and the method for accurate joint directionality analysis is not presented strategically, so it is difficult to apply it in design. Through the results of this study, we would like to propose an flight photographing technique for the investigation of rock joints. As a result of the study, in the case of the joint investigation of the rock slope using UAV, it was necessary to change conditions such as altitude, aerial photography route, and overlap according to the size of the joint according to the site conditions.

• 한국측량학회지
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• 제28권4호
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• pp.441-448
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• 2010

본 논문은 계절별로 획득된 항공라이다 자료로부터 수고를 추정하여 수관울폐도와 자료융합에 따른 영향을 분석하였다. 수고추정은 수목에서 반사되는 신호(First Return : FR)와 지표에서 반사되는 신호(Last Return : LR)를 추출하고, 영상분할을 통해 수목개체를 가정하여 개체목별 수고를 획득하는 방법을 적용하였다. 계절별 자료를 통해 획득한 각 수고 자료와 융합자료로부터 획득한 수고의 결과를 비교하였으며, 수고측정기를 사용하여 현지 측정을 하여 정확성을 비교하고, 항공라이다를 통해 획득한 자료들을 융합한 결과에 대한 그 활용성을 검토하였다. 실험 결과, 수목개체를 위한 영상분할 결과는 0.5미터 점군간격보다 1미터 간격이 현지조사 결과와 가까웠으며, 수목고의 경우 각 계절별 자료보다 융합자료를 활용한 결과가 현지 측정 결과에 접근하고 있음을 알 수 있었다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.405-410
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• 2004

In mid-90's, the Korean government introduced the GIS(Geographic Information System) to digitalize every topography of national land and thereby, index locations and attributes of various urban facilities to construct a system whereby every information could be managed and operated in an integrated way, but the reliability of such geographic information has yet to be tested, much less its modification, complementation and maintenance. Under such circumstances, this study was aimed at constructing a reference point infrastructure for Seoul and Kyonggi area and comparing the data obtained from the GPS operation and various facility location data with the existing GIS data to address the problems of GIS operation and suggest their solutions. As a result of calculating the GPS reference point data and analyzing the deviations of the unknown point data in comparison with the fixed point ones, it was found that the horizontal location values were reliable within +/- 5cm, but that the above-sea level values varied as much as 1.4m depending on the deployment of pre-set fixed points determined by the direct level gauging. In addition, as a result of directly surveying major facilities around the roads based on the coordinates of the urban reference points networked with such a reference point system to check their conformity to existing data, it was confirmed that the difference was as wide as 2m. Such differences may be attributable to the fact that the data with their geographic information not confirmed are used as basic data for GIS. Hence, this study suggests the ways to set the absolute geographic data based on reference points and test the reliability of existing data and thereby, suggests a methods to solve the problems.

• 한국측량학회지
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• 제22권3호
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• pp.269-275
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• 2004

지리정보는 도시 및 국토의 이용 및 관리, 도시계획, 환경 및 재난관리, 교통ㆍ물류 등 국가, 공공기관뿐만 아니라 실생활에서도 광범위하게 활용되고 있다. 그러나 다양한 방법으로 각자의 필요성에 의하여 지리정보를 구축하고 있어 데이터간의 불일치, 불필요한 비용의 중복투자, 의사결정의 어려움 등의 문제점이 발생하였다. 이러한 문제점을 해결하기 위하여 국가적 차원에서 모든 지리정보를 공동으로 활용하기 위한 기본지리정보구축의 필요성이 대두되었다. 이에 따라 기본지리정보는 국가지리정보체계의구축및활용에관한법률에 8개 분야가 선정되었고 기본지리정보구축 추진협의회 협의를 거쳐 8개 분야의 세부 항목으로 19개 항목이 협의ㆍ선정되었다. 본 연구는 계층분석(Analytical Hierarchy Process)과 의사결정나무분석을 이용하여 19개 항목(도로, 철도, 해안선, 측량기준점 등)간의 상대적 중요도를 도출하였고 도출된 중요도에 따라 각 항목의 구축 우선순위를 그룹화하여 제시하였다. 본 연구 결과를 적용하여 기본지리정보 구축시 사업의 우선순위를 정하고 그 순위에 따라 추진함으로써 국가 예산을 효율적으로 집행할 수 있을 것으로 기대된다.

• 한국측량학회지
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• 제37권5호
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• pp.379-388
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• 2019

Recently, a technique for acquiring spatial information data using UAV (Unmanned Aerial Vehicle) has been greatly developed. It is a very crucial issue of the GIS (Geographic Information System) mapping system that passes way point in the unmanned airframe and finally measures the accurate image and stable localization to the desired destination. Though positioning using DGPS (Differential Global Navigation System) or RTK-GPS (Real Time Kinematic-GPS) guarantee highly accurate, they are more expensive than the construction of a single positioning system using a single GPS. In the case of a low-priced single GPS system, the stability of the positioning data deteriorates. Therefore, it is necessary to supplement the uncertainty of the absolute position data of the UAV and to improve the accuracy of the current position data economically in the operating state of the UAV. The aim of this study was to present an algorithm enhancing the stability of position data in a single GPS mode of UAV with multiple GPS. First, the arrangement of multiple GPS receivers through the center of gravity of the UAV were examined. Next, MD (Mahalanobis Distance) is applied to detect instantaneous errors of GPS data in advance and eliminate outliers to increase the accuracy of previously collected multiple GPS data. Processing procedure for multiple GPS reception data by applying the center of the triangular method were presented to improve the position accuracy. Second, UAV navigation systems integrated multiple GPS through configuration of the UAV specifications were implemented. Using the unmanned airframe equipped with multiple GPS receivers, GPS data is measured with the TCM (Triangular Center Method). In addition, UAV equipped with multiple GPS were operated in study area and locational accuracy of multiple GPS of UAV with VRS (Virtual Reference Station) GNSS surveying were compared. The result showed that the error factors are compensated, and the error range are reduced, resulting in the reliability of the corrected value. In conclusion, the result in this paper is expected to realize high-precision position estimation at low cost in UAV using multiple low-cost GPS receivers.