File Name: close range photogrammetry principles techniques and applications .zip
Stereo photogrammetry has been used in this study to analyse and detect movements within the Lecture theater of School of Environmental Technology of Federal University of Technology Minna via the use of Kalman filter algorithm. The essential steps for implementation of this method are herein highlighted and results obtained indicate Ins.
Because the observed movements were insignificant, the building has been classified as stable. With increase in the rate of construction of skyscrapers, high rise buildings and other elevated structures in order to house the increasing population within the built environment, building deformation studies to mitigate the sudden failure of these structures have become inevitable Ajibade, ; Olagunju et al.
Deformation studies of such large structures are required in order to ensure that the structures are exhibiting safe deformation behaviour.
Deformation refers to the changes a deformable body undergoes in its shape, dimension and position Wan Aziz et al. As buildings get deformed due to age and wearing out of its constituent materials, their load-bearing capacity alters and this influences their dynamic response in terms of changes in shape, dimensions and strength.
Over the years, several techniques have been utilized for monitoring the rate of deformation of structures. These techniques involve the use of either or a combination of geodetic surveys Erol et al. The photogrammetric method has been found to be fast, accurate, cost effective and reliable Mills and Barber, ; Wang et al.
This method has gained prominence due to its capability for accurate and fast non-contact measurement of solid bodies Luhmann et al. The photogrammetric method of deformation analysis is entirely based on the principle of close-range photogrammetry CRP and as such, observations are made from accurately coordinated control points that are located at distance not exceeding m from the observed structure. One advantage of the photogrammetric method is the ease and speed of data acquisition per observational epoch, thereby reducing the cost and time required in data gathering for deformation studies Albert et al.
Large volume of data relating to the object to be studied is collected with just a snap of the camera. While the use of Terrestrial Laser Scanners TLS that is usually classified as being under geotechnical measurements also offers similar advantage, digital photographs have lower space requirements than TLS outputs.
As such, due to manageable storage size, the output from CRP is easier to process with medium space personal computers PC's unlike their TLS counterpart. Earlier works on the use of photogrammetric measurements for building deformation analysis have been done using photogrammetric software to generate 3D models of buildings and analysing positional differences between photo-generated coordinates and established ground positions over-time. Wang et al. Thereafter, the study determined deformations by comparing the differences in linear measurements between points on the photogrammetric model and physical measurements taken as control points a method known as check measurements.
Similar method was utilized by Fawzy to determine deformations in a 41 m tall building in Egypt using the Photo modeler software. The suitability of stereo-photogrammetry to measure lateral and vertical deformation of a reinforced concrete column under dynamic loading had been studied by Alemdar et al. Chounta and Ioannidis used 3D photo-grammetric coordinates obtained from space resection and intersection to calculate point displacements on a concrete beam during a loading test. Images were taken in load free state and in every loading epoch until the beam reaches its breaking curve.
Also, Lee and Han utilized the 3D coordinates of targets on a bridge obtained from photogrammetric measurements to determine the deformation on a bridge by analysing the differences between coordinates at different epochs with specified baseline coordinates. The study used a photogrammetric board to determine the interior and exterior orientation parameters. Baseline coordinates for the deformation analysis was obtained from TLS data.
In order to ensure consistency in the points whose differences were to be analysed, a target-matching of sequence of photos was developed.
Invariably, we infer from previous studies that the photo-grammetric technique has been very effective for static deformation monitoring. However, most of the current engineering applications require monitoring of movement behaviours; and as such, a kinematic deformation model that determines displacements, velocities, acceleration as well as time variation is required.
The most frequently utilized kinematic model is the Kalman filter. The Kalman filter KF algorithm has been used extensively in building deformation studies where GPS or other ground survey techniques have been used for field measurement, after which subsequent analysis of movements is done using KF Ehigiator-Irughe and Ehigiator, ; Gulal, Nevertheless, its use in photogrammetric deformation analysis is not common.
The application of KF in photogrammetry has been limited to localization positioning where the KF algorithm is used to model the navigation path of a robot in robotic sciences Jung, This research therefore integrates the use of 2D photogrammetric transformation models to transform photo coordinates to ground coordinates, thereafter, utilizing the KF algorithm to detect possible movements in the building.
Stereo photograph of a building was taken using a digital camera mounted on a tripod stand in-order to analyse the possibility of 2D movements within the building. This research has focused on both vertical and lateral tilts of the structure studied. The choice of stereo-photography for 2D analysis in this study is to minimize the effect of parallax in the resulting 3D image of the captured scene. The structure has been in use for over 10 years and hosts approximately persons at full capacity.
Citation: Reports on Geodesy and Geoinformatics , 1; The study presents an empirical research on the use of photogrammetric-derived coordinates for performing 2D deformation analysis of a building. The materials used for the study are as presented in Table 1. First, conventional ground survey technique is used to determine the coordinates of two selected ground control points GCPs from where the overlapping photographs were taken. In-order to achieve the desired results, the point location were fixed such that there was a complete coverage of the building from both control points.
The Leica Total station was used to coordinate the GCPs and a sketch of the traverse observation is shown in Figure 2. Figure 3 depicts the location of the pillars viz. Thereafter, suitable locations on the object are marked to be used as Photo Control Points PCPs or targets, which would be easily identifiable on the photograph. The object space coordinates of the chosen PCPs would first be determined by 2-points intersection.
This first determination of the PCP coordinates by 2-point intersection would serve as baseline values for the deformation analysis. The choice of selection of the points was to ensure that the points picked was within the load bearing portion of the building.
Therefore, with the chosen points, the absolute movement of the building was determined. Presented below are the results obtained from the different work phases. Table 2 shows the summary of accuracy achieved during the traverse operation conducted to determine the coordinates of the GCPs. As seen in the table, a linear accuracy of was obtained, which indicates a third order accuracy traverse.
This implies a possibility of a linear displacement of 1 m in every m. Also, the transformation parameters determined for converting pixel to object coordinates are presented in Table 3. The parameters were used in a polynomial transform to determine ground coordinates from pixel coordinates.
It should be noted that although a total of 10 PCPs are located across each photograph, four of the points not used for deformation analysis were left out for validation. This implies that the derived transformation parameters are correct and computed coordinates useful for sub-millimeter analysis. The computed coordinates of the four PCPs used for the deformation analysis obtained from the transformation of pixel coordinates to object space coordinates at the three observation epochs are presented in comparison with the observed ground coordinates of same points in Table 4.
Very close similarity is seen in the field measurements and the photogrammetric derived coordinates. The correlation noticed in both datasets illustrates a measure of the precision of the transformation method used for converting pixel coordinates to object space coordinates. This high level of correlation is expected between both datasets being a true indication of reality. Furthermore, the correlation also indicates that transformation method used in the study is comparable to the space resection and intersection methods.
Each observation epoch consists of a set of stereo-pair observations taken to the building in a day. The epochs were taken at two months interval to each other. Differences between the successive epochs and the baseline coordinates are presented in Tables 5—7. This indicates a centimetre-level coordinate difference and suggests near stability of the structure.
The result of the KF analysis is presented in Table 8. The observed differences in coordinates between successive observation epochs and the baseline observation were used as input data to determine the initial and subsequent state vectors of the building.
The results from the KF analysis indicate that the building is stable over a period of four months within which the study was carried out. This is seen by very small and Ins. Table 9 shows the detected motion in terms lateral and vertical velocity at the points A—D during the 3 observation epochs.
Table 2 indicates an acceptable level of accuracy 3 rd order in the initial traverse with which the coordinates of the GCPs were determined. The KF analysis Tables 8 and 9 showing horizontal and vertical motions at the check points for each of the observational epochs indicate that at the first epoch, all check points of the structure are stable, while at the second and third epoch bi-monthly , Ins. This result is consistent with the findings of Ehigiator-Irughe and Ehigiator where a maximum velocity of 0.
A possible reason for such great stability is the presence of a vertical column along its path. These results are graphically substantiated as shown in Figure 4. Similar trend but of greater magnitude is noticed at the second check point. The reason for this sudden deviation from previous trend is uncertain and should be investigated by a loner observational period with a more consistent interval of observations. The findings of the research are illustrated by charts presented in Figure 4.
This general trend indicates increasing deformation within the structure with continuous use of building over time. This trend is expected and justifies the need for routine maintenance of the structure as the building continues to age. The result is in agreement with the result of Mustafin et al. Structural members undergo elastic deformations due to dead load or super imposed live loads.
Consequently, elastic deformations are load induced deformations that reverse themselves when such loads are removed. By implication, it can be inferred that while emphasis need be placed on magnitude of movements in buildings, the direction of movement overtime is also a very useful indication of the type or nature of deformation such buildings are experiencing. Photogrammetric derived coordinates obtained by the application of a polynomial transform to convert pixel coordinates of a stereo-pair to object coordinates have been analysed by the KF algorithm to detect movements of a building.
The results obtained indicate the viability of the use of stereo photogrammetry technique for detecting movements in any engineering structure. The School of Environmental Lecture Theatre study area has been studied via this procedure and discovered to be generally stable with Ins.
Such information will inform the university administrators on the appropriate duration for building reinforcements, points to be strengthened and also number of years the structure can withstand prior to a possible collapse. Ajibade, S. Horizontal and Vertical controls for the study and monitoring of structure movement.
Albert, J. Pilot studies on photogrammetric bridge deformation measurement. Alemdar, Z. Photogrammetric measurements of RC bridge column deformations. Chounta, I. High accuracy deformation monitoring of a concrete beam using automatic photo-grammetric techniques. Proceedings of the FIG Working Week —Knowing to manage the territory, protect the environment, evaluate the cultural heritage.
Close Range Photogrammetry
Close Range Photogrammetry. Principles, Methods, and Applications. Whittles Publishing, Reviewed by. Kai Huang Australia. Return to Home Page. Photogrammetry is a fascinating subject whose aim is to derive the shape and location of an object from one or more of its photographs.
Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant imagery and other phenomena. Photogrammetry appeared in the middle of the 19th century , almost simultaneously with the appearance of photography itself. The use of photographs to create topographic maps was first proposed by the French surveyor Dominique F. Arago in about The term photogrammetry was coined by the Prussian architect Albrecht Meydenbauer,  which appeared in his article "Die Photometrographie.
Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. This paper outlines two examples of application of close-range photogram metry, their preliminary results and observations. The first application is id entification and measurement of deformations and displacements of the vehicle chas sis after a frontal crash-test. This is done by comparison between the preand postcras h models and measurements. The second mentioned application is determination of the road p avement macrotexture, where the photogrammetry can serve as an alternative method. Save to Library.
USE OF CLOSE-RANGE PHOTOGRAMMETRY IN FORENSIC SCIENCE
The main objective of this study is to present a new method to carry out measurements so as to improve the positioning verification step in the wind hub part dimensional validation process. This enhancement will speed up the measuring procedures for these types of parts. An industrial photogrammetry based system was applied to take advantage of its results, and new functions were added to existing capabilities. In addition to a new development based on photogrammetry modelling and image processing, a measuring procedure was defined based on optical and vision system considerations. The component analyzed in this article is part of several wind turbine models and from an operational point of view is one of the most critical, together with other components such as shovels and lift towers [ 1 ].
Stereo photogrammetry has been used in this study to analyse and detect movements within the Lecture theater of School of Environmental Technology of Federal University of Technology Minna via the use of Kalman filter algorithm. The essential steps for implementation of this method are herein highlighted and results obtained indicate Ins. Because the observed movements were insignificant, the building has been classified as stable.
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