• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.22 no.3
• /
• pp.285-291
• /
• 2004

GPS photogrammetry or the GPS/INS photogrammetry, which are based on the direct measurement of the projection centers and attitude at the moment of camera exposure time through loading the GPS receiver or INS in aircraft. Both photogrammetric methods can offer us to acquire the exterior orientation parameters with only minimum ground control points, even the ground control process could be completely skipped. Consequently, we can drastically reduce the time and cost for the mapping process. In this thesis, test flight was conducted in Suwon area to evaluate the performance of accuracy and efficiency through the analysis of results among the three photogrammetric methods, that is, traditional photogrammetry, GPS photogrammetry and GPS/INS photogrammetry. Test results shows that a large variety of advantages of GPS photogrammetry and GPS/INS photogrammetry against traditional photogrammetry is to be verified. Especially, the number of ground control points for the exterior orientation could be saved more than 70～80%, respectively.

• Journal of Korean Society for Geospatial Information Science
• /
• v.16 no.1
• /
• pp.43-48
• /
• 2008

In this study, it was estimated efficiency of GPS/INS photogrammetry by comparison of accuracy and economical efficiency between conventional aerial triangulation and GPS/INS aerial triangulation at the base of large scale digital mapping using GPS/INS aerial survey. The results of aerial triangulation with GPS/INS showed that 40% of working amount was reduced in the process of ground control point survey compared to conventional aerial triangulation. In case of 1/5000 scale aerial triangulation, the results showed that 55% GCP work was reduced in 10 and 20 block size, and 60% GCP work was reduced in 30 block size, under the assumption of keeping the same accuracy.

• Korean Journal of Remote Sensing
• /
• v.24 no.4
• /
• pp.381-388
• /
• 2008

In the common practice of air-photographing measurement aerial-photogrammetric, the location of camera at the time of photographing is identified by performing aerotriangulation. However, installing ground-base station to enable aerotriangulation takes majority portion of a map making cost. Aerial-photogrammetric has shown a great improvement helped by steady upgrading in equipment and development in quantitative study. Aerotriangulation can be replaced by Direct Georeferencing, which uses GPS/INS to identify a camera location and to produce detailed information. An innovative technique replacing aerotriangulation, it has a disadvantage that base station has to be available in the area of photographing. The study intends to suggest a method applying VRS in GPS/INS aerotriangulation. Despite the fact that Direct Georeferencing is the innovated technique which substitutes existing aerotriangulation, it still need to install the ground-base station in GPS/INS aerotriangulation. GPS/INS data was analyzed with 4 different cases in order to accomplish the purpose of this study. In addition, in the thesis, it was approved that VRS can be utilized to make small-scale map as accurate as base station. This study is expected to improve the efficiency of work by showing that VRS can be used not only in base station but also enabling base station in the ground-access challenging area.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.1
• /
• pp.71-78
• /
• 2009

In general, it is necessary to establish the dedicated GPS base station at the central point of the survey area in GPS/INS aerotriangulation. Although this base station is needed to achieve the required survey accuracy, there are some difficulties in practical operation. To tackle these difficulties and to achieve the effective GPS/INS aerotriangulation, the GPS data of CORS was interpolated and used in stead of those of the usual ground base station. Through this study, it was found that the interpolated CORS data was accurate enough to substitute dedicated GPS base station in GPS/INS aerotriangulation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.22 no.1
• /
• pp.53-62
• /
• 2004

This paper deals with a new approach to acquire the exterior orientation parameters based on GPS(Global Positioning System) in combination with IMU(Inertial Measuring Unit), which enables us to achieve the same accuracy with minimal ground control points comparing to the conventional photogrammetric method. To prove the possibility of practical use of GPS/INS photogrammetry, a survey flight was conducted loading with all necessary photographing systems. The observed data set by GPS/IMU were analyzed and verified :he accuracy performance of kinematic GPS, and also compared to those of conventional photogrammetry in various points of view.

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

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.3
• /
• pp.323-330
• /
• 2005

More than ten years after the era of GPS-Photogrammetry which could provide us only three projection center of all six exterior orientation parameters, direct georeferencing with GPS/INS is now becoming a standard method for image orientation. Its main advantage is to skip or reduce the indirect ground control process. This paper describes the experimental test results of integrated sensor orientation with a commercial GPS/IMU system to approve its performance in determination of exterior orientation. For this purpose two different imaging blocks were planned and the area was photographed at a large photo scale of 1:5,000 and a medium photo scale of 1:20,000. From these data set a variety of meaningful results was acquired, i.e., the accuracy. potential of exterior orientation from direct georeferencing and combined block adjustment using these data considering different photo scales and conditions.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2004.04a
• /
• pp.39-44
• /
• 2004

In this thesis, two test flights were conducted in Gwacheon and Suwon area to evaluate the performance of accuracy and efficiency through the analysis of results among the three photogrammetric methods, that is, traditional photogrammetry, GPS -Photogrammetry and GPS/INS-Photogrammetry. Test results shows that a large variety of advantages of GPS-Photogrammetry and GPS/INS-Photogrammetry against traditional photogrammetry is to be verified. Especially, the number of ground control points for the exterior orientation could be saved more than 70-80%, and the cost for map production 30-50%, respectively. In addition, it was convinced that the large reduction of control points has not any effect on the block accuracy. It was also proved that the number of required ground control points for GPS/INS-Photogrammetry, is similar to that of GPS-Photogrammetry. Therefore it should be noted that GPS -Photogrammetry is more efficient in the aspect of reduction of mapping cost against GPS/INS-Photogrammetry, installing only an existing GPS receiver on survey aircraft to avoid high economic burden of procurement for integrated GPS/INS equipment.

• 한국공간정보시스템학회:학술대회논문집
• /
• 1999.06a
• /
• pp.217-228
• /
• 1999

최근 범국가적인 GIS구축사업을 위한 효율적인 지형공간정보취득기법에 대한 요구가 날로 증가하고 있다. 이는 HW, SW 및 데이터로 구성되는 GIS구축에서 지형자료가 차지하는 비중과 이의 취득에 필요한 노력이 매우 중요함을 반증하고 있다. 이에 부응하여 국내에서도 재래식측량기법의 자동화/현대화에서부터 GPS측량기술의 도입, Airborne-항공사진측량기법의 개발 및 고해상도위성영상의 활용방안에 이르기까지 새로운 측량기술에 대한 다양한 연구와 기술축적을 서두르고 있는 실정이다. 그러나 위의 어떠한 측량기법도 단독으로는 정확도, 신속성, 경제성, 현재성 등 GIS 자료취득의 모든 요구조건을 만족하는 Total Solution이 되지 못하고 있다. 따라서 본 연구에서는 매핑과 GIS-자료취득에 활용되고 있는 여러 가지 항공측량기술의 현황과 장단점을 살펴보았다. 또한 위성에 의한 위치결정시스템인 GPS와 관성항행장치인 INS를 결합하여 항공측량 분야에 필요한 센서의 위치와 회전각을 결정하므로서 시너지(Synergy)효과를 높이는 기법을 소개한다.

• Spatial Information Research
• /
• v.12 no.2
• /
• pp.181-191
• /
• 2004

Nowadays, GPS-photogrammetry can be applied to the basemap production, a land register and NGIS. And from now on, as the increase of GPS receiver rate, the study on the interpolation methods considering the exact movement of an aircraft at photoflight and the study on the supplement of GPS defect by INS are required continuously. GPS-Photogrammetry, which are based on the direct measurement of the projection centers and attitude at the moment of camera exposure time through loading the GPS receiver in aircraft. This photogrammetric methods can of for us to acquire the exterior orientation parameters with only minimum ground control points, even the ground control process could be completely skipped. Consequently, we can drastically reduce the time and cost far the mapping process. In this thesis, two test flights were conducted in area to evaluate the performance of accuracy and efficiency through the analysis of results between the two photogrammetric methods, that is, traditional photograrammetry, GPS-Photogrammetry. Test results shows that a large variety of advantages of GPS-Photogrammetry against traditional photogrammetry is to be verified. Especially, the number of ground control points for the exterior orientation could be saved more than 70～80%, and the cost far map production 30～50%, respectively. In addition, it was convinced that the large reduction of control points has not any effect on the block accuracy.