The purpose, classification, required accuracy and surveying methods of control work for close range photogrammetry have been briefly stated. The different methods for definition of space, object coordinate system are...The purpose, classification, required accuracy and surveying methods of control work for close range photogrammetry have been briefly stated. The different methods for definition of space, object coordinate system are also reviewed. It is suggested that the habitu-ally-practised rotation angle system for aerophotogrammetry in China should be used for the future teaching and resaarching work in the close range photogrammetry, and that the rotation angle system for terrestrial deformation photogrammetry should be left out in order to avoid the confuse and reduce the amount of expanse for making softwares. It has been emphasized that there are three improtant aspects in the close range control work with high accurary using the conventional method of engineering surveying: the use of standard scale for measurement of distance between two general stations, the accurate determination of start direction line between two general stations and the handling method of influence of 2C change. A method for setting up industrial surveying control net with extra-high accuracy ±(0.05–0.20) mm is presented by the author. This kind of industrial control net is necessary for batch process of large industrial components with purposes of measurement, inspect and lofting. There are some special methods of control work in the close range photogrammetry, including two methods presented by the author.展开更多
It is usually a time-consuming process to real-time set up 3D digital surface model(DSM) of an object with complex surface.On the basis of the architectural survey project of"Chilin Nunnery Reconstruction",t...It is usually a time-consuming process to real-time set up 3D digital surface model(DSM) of an object with complex surface.On the basis of the architectural survey project of"Chilin Nunnery Reconstruction",this paper investigates an easy and feasible way,that is,on project site,applying digital close range photogrammetry and CAD technique to establish the DSM for simulating ancient architectures with complex surface.The method has been proved very effective in practice.展开更多
Close-range photogrammetry is to determine the shape and size of the object, instead of it's absolute position. Therefore, at first, any translation and rotation of the photogrammetric model of the object caused b...Close-range photogrammetry is to determine the shape and size of the object, instead of it's absolute position. Therefore, at first, any translation and rotation of the photogrammetric model of the object caused by whole geodesic, photographic and photogrammetric procedures in close-range photogrammetry could not be considered. However, it is necessary to analyze all the reasons which cause the deformations of the shape and size and to present their corresponding theories and equations. This situation, of course, is very different from the conventional topophotogrammetry. In this paper some specific characters of limit errors in close-range photogrammetry are presented in detail, including limit errors for calibration of interior elements for close-range cameras, the limit errors of relative and absolute orientations in close-range cameras, the limit errors of relative and absolute orientations in close-range photogrammetric procedures, and the limit errors of control works in close-range photogrammetry. A theoretical equation of calibration accuracy for close-range camerais given. Relating to the three examples in this paper, their theoretical accuracy requirement of interior elements of camera change in the scope of ±(0.005–0.350) mm. This discussion permits us to reduce accuracy requirement in calibration for an object with small relief, but the camera platform is located in violent vibration environment. Another theoretical equation of relative RMS of base lines (m S/S) and the equation RMS of start direction are also presented. It is proved that them S/S could be equal to the relative RMS ofm ΔX/ΔX. It is also proved that the permitting RMS of start direction is much bigger than the traditionally used one. Some useful equations of limit errors in close-range photogrammetry are presented as well. Suggestions mentioned above are perhaps beneficial for increasing efficiency, for reducing production cost.展开更多
Automatic extraction of road and linear structure from remote sensing images is a very important problem. This paper analyses several existing methods of the automatic road and linear structure extraction by using som...Automatic extraction of road and linear structure from remote sensing images is a very important problem. This paper analyses several existing methods of the automatic road and linear structure extraction by using some multi-spectral remote sensing images acquired from different spatial resolutions, districts and road characteristics. Their advantages and disadvantages have been generalized.展开更多
A method for shadow detection and compensation for color aerial images is presented. It is considered that the intensity value of each image pixel is the product of illumination function and ground object reflection, ...A method for shadow detection and compensation for color aerial images is presented. It is considered that the intensity value of each image pixel is the product of illumination function and ground object reflection, and the shadowed regions on the image are mainly caused by the short of illumination, so the information compensation for the shadowed regions should concentrate on the illumination adjustment of concerned area on the basis of the analysis of whole image. The shadow detection and compensation procedure proposed by this paper consists of four steps.展开更多
This thesis illustrates the method and precision of employing analytical photogrammetry to carry out similar materials model experiment in surveying the displacement of surveying points and analyzing the deformation l...This thesis illustrates the method and precision of employing analytical photogrammetry to carry out similar materials model experiment in surveying the displacement of surveying points and analyzing the deformation law of rock layersand earths surface according to the results in the studying the deformation law of the earths surface caused by extracting mine coal underground.展开更多
In close-range photogrammetry, 3D information acquisition is based on image matching. The application of code marker helps to improve the level of automatic matching and the matching accuracy. This paper inyestigates ...In close-range photogrammetry, 3D information acquisition is based on image matching. The application of code marker helps to improve the level of automatic matching and the matching accuracy. This paper inyestigates the application of inertia ellipse algorithm to code marker matching. We can calculate the inertia ellipse of a target with a certain boundary. First, the method is applied to a single code marker; the angle and scaling are valid. Then, the paper introduces the multi code markers matching method by the inertia ellipse. Rotation and scaling changes of homonymy images can be calculated by inertia ellipse algorithm. These parameters can be used for code marker matching in arbitrary attitude close-range photogrammetry.展开更多
文摘The purpose, classification, required accuracy and surveying methods of control work for close range photogrammetry have been briefly stated. The different methods for definition of space, object coordinate system are also reviewed. It is suggested that the habitu-ally-practised rotation angle system for aerophotogrammetry in China should be used for the future teaching and resaarching work in the close range photogrammetry, and that the rotation angle system for terrestrial deformation photogrammetry should be left out in order to avoid the confuse and reduce the amount of expanse for making softwares. It has been emphasized that there are three improtant aspects in the close range control work with high accurary using the conventional method of engineering surveying: the use of standard scale for measurement of distance between two general stations, the accurate determination of start direction line between two general stations and the handling method of influence of 2C change. A method for setting up industrial surveying control net with extra-high accuracy ±(0.05–0.20) mm is presented by the author. This kind of industrial control net is necessary for batch process of large industrial components with purposes of measurement, inspect and lofting. There are some special methods of control work in the close range photogrammetry, including two methods presented by the author.
文摘It is usually a time-consuming process to real-time set up 3D digital surface model(DSM) of an object with complex surface.On the basis of the architectural survey project of"Chilin Nunnery Reconstruction",this paper investigates an easy and feasible way,that is,on project site,applying digital close range photogrammetry and CAD technique to establish the DSM for simulating ancient architectures with complex surface.The method has been proved very effective in practice.
文摘Close-range photogrammetry is to determine the shape and size of the object, instead of it's absolute position. Therefore, at first, any translation and rotation of the photogrammetric model of the object caused by whole geodesic, photographic and photogrammetric procedures in close-range photogrammetry could not be considered. However, it is necessary to analyze all the reasons which cause the deformations of the shape and size and to present their corresponding theories and equations. This situation, of course, is very different from the conventional topophotogrammetry. In this paper some specific characters of limit errors in close-range photogrammetry are presented in detail, including limit errors for calibration of interior elements for close-range cameras, the limit errors of relative and absolute orientations in close-range cameras, the limit errors of relative and absolute orientations in close-range photogrammetric procedures, and the limit errors of control works in close-range photogrammetry. A theoretical equation of calibration accuracy for close-range camerais given. Relating to the three examples in this paper, their theoretical accuracy requirement of interior elements of camera change in the scope of ±(0.005–0.350) mm. This discussion permits us to reduce accuracy requirement in calibration for an object with small relief, but the camera platform is located in violent vibration environment. Another theoretical equation of relative RMS of base lines (m S/S) and the equation RMS of start direction are also presented. It is proved that them S/S could be equal to the relative RMS ofm ΔX/ΔX. It is also proved that the permitting RMS of start direction is much bigger than the traditionally used one. Some useful equations of limit errors in close-range photogrammetry are presented as well. Suggestions mentioned above are perhaps beneficial for increasing efficiency, for reducing production cost.
文摘Automatic extraction of road and linear structure from remote sensing images is a very important problem. This paper analyses several existing methods of the automatic road and linear structure extraction by using some multi-spectral remote sensing images acquired from different spatial resolutions, districts and road characteristics. Their advantages and disadvantages have been generalized.
文摘A method for shadow detection and compensation for color aerial images is presented. It is considered that the intensity value of each image pixel is the product of illumination function and ground object reflection, and the shadowed regions on the image are mainly caused by the short of illumination, so the information compensation for the shadowed regions should concentrate on the illumination adjustment of concerned area on the basis of the analysis of whole image. The shadow detection and compensation procedure proposed by this paper consists of four steps.
文摘This thesis illustrates the method and precision of employing analytical photogrammetry to carry out similar materials model experiment in surveying the displacement of surveying points and analyzing the deformation law of rock layersand earths surface according to the results in the studying the deformation law of the earths surface caused by extracting mine coal underground.
基金Supported by the Key Laboratory of Precise Engineer & Industry Surveying, State Bureau of Surveying and Mapping(No.PF2009-12)the Key Laboratory of Mapping from Space of State Bureau of Surveying and Mapping(No. 200810)
文摘In close-range photogrammetry, 3D information acquisition is based on image matching. The application of code marker helps to improve the level of automatic matching and the matching accuracy. This paper inyestigates the application of inertia ellipse algorithm to code marker matching. We can calculate the inertia ellipse of a target with a certain boundary. First, the method is applied to a single code marker; the angle and scaling are valid. Then, the paper introduces the multi code markers matching method by the inertia ellipse. Rotation and scaling changes of homonymy images can be calculated by inertia ellipse algorithm. These parameters can be used for code marker matching in arbitrary attitude close-range photogrammetry.
