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1.
数字太原地理空间框架建设项目方案探讨 总被引：2，自引：0，他引：2
介绍了“数字太原”地理空间框架建设的目标、数据形式、系统结构、技术路线和流程,具体说明了地理空间信息平台的建设中的数据内容和地址数据的采集方法,详细介绍了地籍管理系统、矿产资源管理系统、环保监测信息系统、公众服务地理信息系统的建设内容。 相似文献
2.
Geopositioning Accuracy of Ikonos Imagery: Indications from Two Dimensional Transformations 总被引：1，自引：0，他引：1
Earth observation satellites with 1m resolution, such as Space Imaging's Ikonos system, offer the photogrammetric and remote sensing communities a significant new means for geospatial information collection. These satellites possess the potential for pixel-level geopositioning precision and promise timely, highly automated generation of two dimensional (2D) and three dimensional (3D) spatial information products. This paper concentrates on the pursuit of optimal accuracy and considers an essential first step in the evaluation of the Ikonos imaging system, namely the metric integrity of the sensor system. In the absence of sensor calibration information (the camera model), an empirical evaluation approach has been adopted. This involves an assessment of 2D transformations between image and planar object space. It is shown that based on results obtained in the Melbourne Ikonos Testfield, 2D geopositioning to 0.5 m accuracy is possible from the base-level "Geo"product when a modest amount of good quality ground control is available and sub-pixel image mensuration is achieved. These findings are applicable to both near-nadir imagery and oblique stereo images. Moreover, the results obtained suggest that there are no significant geometric perturbations in the sensor system and initial image processing, which augurs well for the successful application of non-collinearity based 3D orientation and triangulation models for Ikonos imagery. 相似文献
3.
D. Rieke-Zapp W. Tecklenburg J. Peipe H. Hastedt Claudia Haig 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(3):248-258
Recent tests on the geometric stability of several digital cameras that were not designed for photogrammetric applications have shown that the accomplished accuracies in object space are either limited or that the accuracy potential is not exploited to the fullest extent. A total of 72 calibrations were calculated with four different software products for eleven digital camera models with different hardware setups, some with mechanical fixation of one or more parts. The calibration procedure was chosen in accord to a German guideline for evaluation of optical 3D measuring systems [VDI/VDE, VDI/VDE 2634 Part 1, 2002. Optical 3D Measuring Systems–Imaging Systems with Point-by-point Probing. Beuth Verlag, Berlin]. All images were taken with ringflashes which was considered a standard method for close-range photogrammetry. In cases where the flash was mounted to the lens, the force exerted on the lens tube and the camera mount greatly reduced the accomplished accuracy. Mounting the ringflash to the camera instead resulted in a large improvement of accuracy in object space. For standard calibration best accuracies in object space were accomplished with a Canon EOS 5D and a 35 mm Canon lens where the focusing tube was fixed with epoxy (47 μm maximum absolute length measurement error in object space). The fixation of the Canon lens was fairly easy and inexpensive resulting in a sevenfold increase in accuracy compared with the same lens type without modification. A similar accuracy was accomplished with a Nikon D3 when mounting the ringflash to the camera instead of the lens (52 μm maximum absolute length measurement error in object space). Parameterisation of geometric instabilities by introduction of an image variant interior orientation in the calibration process improved results for most cameras. In this case, a modified Alpa 12 WA yielded the best results (29 μm maximum absolute length measurement error in object space). Extending the parameter model with FiBun software to model not only an image variant interior orientation, but also deformations in the sensor domain of the cameras, showed significant improvements only for a small group of cameras. The Nikon D3 camera yielded the best overall accuracy (25 μm maximum absolute length measurement error in object space) with this calibration procedure indicating at the same time the presence of image invariant error in the sensor domain. Overall, calibration results showed that digital cameras can be applied for an accurate photogrammetric survey and that only a little effort was sufficient to greatly improve the accuracy potential of digital cameras. 相似文献
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嫦娥三号探测器系统两器分离是着陆后进行的第一个关键动作,也是后续着陆器探测和巡视器月面巡视勘察的基础,解决两器安全分离问题对于整个工程的实施具有重要意义。针对实际任务中对分离决策实时性和可靠性要求高的特点,使用基于着陆器监视相机的单像量测方法对月面环境中障碍物和通信遮挡包络进行分析计算,评估两器分离过程中的不安全因素,为两器分离决策提供支持。介绍了监视相机单像量测和通信遮挡包络计算方法,并对量测精度进行了分析验证。 相似文献
6.
传统的相机检校方法受限于高精度的三维检校场或已知空间结构的检校模板,针对这个问题,在分析智能手机成像特征的基础上,提出一种无需控制信息的相机检校方法。该方法主要包括两个步骤:首先按3×3模式采集影像数据,选取基准影像,分别与其他影像进行相对定向以构建单元模型,通过比例系数进行模型连接后建立自由网模型,将所有摄站点、物方点坐标纳入到统一的基准影像坐标系中;然后以选择的基准影像为参考,并考虑附加参数模型,进行自检校光束法自由网平差,解算其余影像相对于基准影像的方位元素以及附加参数,从而完成相机的检校。实验结果表明,该检校方法是有效的,可显著提高测量的精度。 相似文献
7.
为了确定森林航空摄影的最佳比例尺和波段以及判读像片的放大倍数,我们在广东省南昆山林业遥感试验场,测定了地物光谱,拍摄了不同比例尺的多光谱片和彩色红外片,进行了内业判读、野外检测和综合分析。本文讨论了航空摄影机、胶片、地物光谱反射系数和摄影位移等因素对像片分辨力的影响,用经验关系式估算了南昆山像片的影像分辨力,阐述了内业判读和实地检测的情况。试验表明,在所试验的波长附围内绿波段表达森林影像的效果最佳,用于森林判读的影像分辨力宜放大到3.5线/毫米,若用新型航空摄影机和高分辨力胶片,则用于森林资源调查分类判读的像片比例尺可缩小到1:4.8万。 相似文献
8.
《ISPRS Journal of Photogrammetry and Remote Sensing》2007,61(6):387-399
Test field system calibration will be a fundamental part of the future photogrammetric production line. Accurate calibration and performance evaluations are necessary for fully assessing the stability and accuracy of digital sensing techniques. In this paper, a method of comprehensive geometric calibration in a test field has been developed and empirically tested using eight image blocks collected with three UltraCamD digital large format photogrammetric cameras. Permanent photogrammetric test fields form the basis of the method. Important components of the method are determination of system parameters, evaluation of systematic errors, and assessment of geometric accuracy. The results showed that UltraCamD images contained systematic deformations that could not be modeled with single lens additional parameter models. Good point determination accuracy was obtained despite the systematic errors; the typical accuracy was 2–3 μm in image space in the horizontal coordinates and 0.05–0.09‰ of the object distance in height. One of the cameras had significantly poorer performance. In the worst cases, the horizontal accuracy was 5 μm in image space and the height accuracy was 0.18‰ of the object distance. The analog cameras gave better results than the UltraCamD, but the development of appropriate mathematical models for UltraCamD as well as improvements in digital sensors may change the situation in the near future. 相似文献
9.
Albert K. Chong 《The Photogrammetric Record》2004,19(108):296-310
Generally, a low-cost image-based motion study system consists of a set of two or more video imaging cameras and a set of object space control targets. The control targets are required to provide for the computation of exterior parameters of the video frames of objects in motion. Subsequently, the computed exterior orientation parameters are used to compute the position of the motion targets. In general, the accuracy of the motion data is dependent largely on the accuracy of the 3D coordinates of the control targets, the computed camera and lens parameters and the frame rate of the camera. Obviously, it is difficult to improve the frame rate of a low-cost camera; however, the other factors may be optimised analytically. Optimising the accuracy of the control targets is a straightforward process and is discussed briefly in the paper. Optimising the computed camera and lens parameters was the main focus of the research. Consequently, the paper provides the detail of the developed optimising technique. The results show that an optimal principal distance and other lens parameters can be determined by analysing the error of a set of highly accurate object distances. The evaluation shows that the accuracy of the video motion study system can be improved by as much as six times or a reduction of scaling error from 1·06 to 1·01. 相似文献
10.
J. Kodet K. U. Schreiber J. Eckl C. Plötz S. Mähler T. Schüler T. Klügel S. Riepl 《Journal of Geodesy》2018,92(9):1097-1112
The quality of the links between the different space geodetic techniques (VLBI, SLR, GNSS and DORIS) is still one of the major limiting factors for the realization of a unique global terrestrial reference frame that is accurate enough to allow the monitoring of the Earth system, i.e., of processes like sea level change, postglacial rebound and silent earthquakes. According to the specifications of the global geodetic observing system of the International Association of Geodesy, such a reference frame should be accurate to 1 mm over decades, with rates of change stable at the level of 0.1 mm/year. The deficiencies arise from inaccurate or incomplete local ties at many fundamental sites as well as from systematic instrumental biases in the individual space geodetic techniques. Frequently repeated surveys, the continuous monitoring of antenna heights and the geometrical mount stability (Lösler et al. in J Geod 90:467–486, 2016. https://doi.org/10.1007/s00190-016-0887-8) have not provided evidence for insufficient antenna stability. Therefore, we have investigated variations in the respective system delays caused by electronic circuits, which is not adequately captured by the calibration process, either because of subtle differences in the circuitry between geodetic measurement and calibration, high temporal variability or because of lacking resolving bandwidth. The measured system delay variations in the electric chain of both VLBI- and SLR systems reach the order of 100 ps, which is equivalent to 3 cm of path length. Most of this variability is usually removed by the calibrations but by far not all. This paper focuses on the development of new technologies and procedures for co-located geodetic instrumentation in order to identify and remove systematic measurement biases within and between the individual measurement techniques. A closed-loop optical time and frequency distribution system and a common inter-technique reference target provide the possibility to remove variable system delays. The main motivation for the newly established central reference target, locked to the station clock, is the combination of all space geodetic instruments at a single reference point at the observatory. On top of that it provides the unique capability to perform a closure measurement based on the observation of time. 相似文献
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Bundle triangulation is an efficient tool for spatial point determination in architectural photogrammetry. All the information available in image and object space may be introduced in a combined adjustment yielding high precision and reliability. Camera calibration performed simultaneously with the object restitution process enables the application of convenient and flexible imaging systems based on professional photographic technology. Thus the survey of monuments can be carried out rapidly with a minimum of personnel and equipment. The photogrammetric recording of the basilica of San Francesco in Siena is presented as an example of the application of this survey procedure. The field work was accomplished in a few days. The equipment used consisted of a partial metric camera, an engineering theodolite and a tape. The bundle adjustment results gave spatial object co-ordinates with a r.m.s.e. of ± 15 mm for a point. 相似文献
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G. C. Brock 《The Photogrammetric Record》1968,6(31):32-40
Photography of models and modulation transfer function analysis have been used to investigate the common belief that in aerial photography large-scale images are preferable to small-scale images, even when the resolving power in terms of ground dimensions is the same. The belief was found to be justified for two extreme cases representing, respectively, a small scale, mainly grain-limited system, and a large scale, wholly lens-limited system, for which the ground resolutions were equal on three-bar targets of 3 to 1 contrast (modulation 0–5). Resolving power tests would have been misleading for these two systems even at a target contrast of less than 2 to 1 (modulation less than 0–3). 相似文献
15.
Eija Honkavaara Eero Ahokas Juha Hyypp Juha Jaakkola Harri Kaartinen Risto Kuittinen Lauri Markelin Kimmo Nurminen 《ISPRS Journal of Photogrammetry and Remote Sensing》2006,60(6):387
Test field system calibration will be a fundamental part of the future photogrammetric production line. Accurate calibration and performance evaluations are necessary for fully assessing the stability and accuracy of digital sensing techniques. In this paper, a method of comprehensive geometric calibration in a test field has been developed and empirically tested using eight image blocks collected with three UltraCamD digital large format photogrammetric cameras. Permanent photogrammetric test fields form the basis of the method. Important components of the method are determination of system parameters, evaluation of systematic errors, and assessment of geometric accuracy. The results showed that UltraCamD images contained systematic deformations that could not be modeled with single lens additional parameter models. Good point determination accuracy was obtained despite the systematic errors; the typical accuracy was 2–3 μm in image space in the horizontal coordinates and 0.05–0.09‰ of the object distance in height. One of the cameras had significantly poorer performance. In the worst cases, the horizontal accuracy was 5 μm in image space and the height accuracy was 0.18‰ of the object distance. The analog cameras gave better results than the UltraCamD, but the development of appropriate mathematical models for UltraCamD as well as improvements in digital sensors may change the situation in the near future. 相似文献
16.
As a model for sensor orientation and 3D geopositioning for high-resolution satellite imagery (HRSI), the affine transformation from object to image space has obvious advantages. Chief among these is that it is a straightforward linear model, comprising only eight parameters, which has been shown to yield sub-pixel geopositioning accuracy when applied to Ikonos stereo imagery. This paper aims to provide further insight into the affine model in order to understand why it performs as well as it does. Initially, the model is compared to counterpart, ‘rigorous’ affine transformation formulations which account for the conversion from a central perspective to affine image. Examination of these rigorous models sheds light on issues such as the effects of terrain and size of area, as well as upon the choice of reference coordinate system and the impact of the adopted scanning mode of the sensor. The results of application of the affine sensor orientation model to four multi-image Ikonos test field configurations are then presented. These illustrate the very high geopositioning accuracy attainable with the affine model, and illustrate that the model is not affected by size of area, but can be influenced to a modest extent by mountainous terrain, the mode of scanning and the choice of object space coordinate system. Above all, the affine model is shown to be both a robust and practical sensor orientation/triangulation model with high metric potential. 相似文献
17.
介绍了一种方便实用的影像匹配方法─—多层动态窗口影像匹配法，并将其应用于自动相对定向中，得到了比较满意的结果。该匹配方法利用金字塔格网、动态窗口匹配以及最小二乘影像匹配，无需任何有关像片方位的验前知识以及物方空间的任何信息，具有很高的匹配成功率。 相似文献
18.
Underwater photogrammetry provides an efficient means for documentation of environments which are complex and have limited accessibility. Yet the establishment of reference control networks in such settings is oftentimes difficult. In this regard, use of the coplanarity condition, which requires neither knowledge of object space coordinates nor setting a reference control network, seems to be an attractive solution. However, the coplanarity relation does not hold in such environments because of the refraction effect, and methods that have been proposed thus far for geometrical modeling of its effect require knowledge of object-space quantities. Thus, this paper proposes a geometrically-driven approach which fulfills the coplanarity condition and thereby requires no knowledge of object space data. Such an approach may prove useful not only for object space reconstruction but also as a preparatory step for application of bundle block adjustment and for outlier detection. All are key features in photogrammetric practices. Results show that no unique setup is needed for estimating the relative orientation parameters using the model and that high levels of accuracy can be achieved. 相似文献
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Exactly capturing three dimensional (3D) motion information of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision system and a method for determining 3D motion parameters of an object from binocular sequence images are introduced. The main steps include camera calibration, the matching of motion and stereo images, 3D feature point correspondences and resolving the motion parameters. Finally, the experimental results of acquiring the motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned method are presented. 相似文献
20.
Zhonghua Hong Shengyuan Xu Yun Zhang Yanling Han Yongjiu Feng 《Journal of the Indian Society of Remote Sensing》2018,46(12):2081-2092
Ziyuan-3 (ZY-3) satellite is the first civilian stereo mapping satellite in China and was designed to achieve the 1: 50,000 scale mapping for land and ocean. Rigorous sensor model (RSM) is required to build the relationship between the three-dimensional (3D) object space and two-dimensional (2D) image space of ZY-3 satellite imagery. However, each satellite sensor has its own imaging system with different physical sensor models, which increase the difficulty of geometric integration of multi-source images with different sensor models. Therefore, it is critical to generate generic model, especially rational polynomial coefficients (RPCs) of optical imagery. Recently, relatively a few researches have been conducted on RPCs generation to ZY-3 satellite. This paper proposes an approach to evaluate the performance of RPCs generation from RSM of ZY-3 imagery. Three scenario experiments with different terrain features (such as ocean, hill, city and grassland) are designed and conducted to comprehensively evaluate the replacement accuracies of this approach and analyze the RPCs fitting error. All the experimental results demonstrate that the proposed method achieved the encouraging accuracy of better than 1.946E?04 pixel in both x-axis direction and y-axis direction, and it indicates that the RPCs are suitable for ZY-3 imagery and can be used as a replacement for the RSM of ZY-3 imagery. 相似文献