Browse Topic: Photogrammetry

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Geometric Derivation of Camera Equations 2022-01-100403/29/2022
Photogrammetry, camera matching, and model-based image matching are commonly used techniques to analyze video for accident reconstruction and other forensic applications. Investigators are often tasked with determining the speed of a vehicle, person, or other object in a video of an incident, or with taking measurements from photographs. All such calculations are based on fundamental geometric principles governing image projection inside a camera. Most treatments in the literature express the image projection equations either in very simple terms for specific cases or in compact matrix notation that is difficult to apply. The purpose of this paper is to present a geometric derivation of the image projection equations in a straightforward form that can be readily applied by a qualified investigator without the need for specialized software. In addition, a simple brute force optimization procedure is described to perform camera matching and model-based image matching. Examples are
Funk, James
Technical Paper
Positional Accuracy of Portable GPS Devices during Different Ride Stages2022-01-099203/29/2022
GPS devices can produce a wealth of data about cyclists’, scooterists’, and other riders’ road paths and route usage. However, prior research has demonstrated that GPS positional accuracy is less reliable for more nuanced roadway positioning, such as which lane a vehicle occupies, as well as within-lane movements, such as acceleration and deceleration⁠. This limitation presents a substantial challenge for crash reconstructionists that may have access to GPS data and require second-by-second positional accuracy to determine such nuanced maneuvers and vehicle positioning in their analysis. The purpose of this study was to examine the positional accuracy of several GPS units during three different ride stages: acceleration, deceleration, and constant speed. The same devices were also tested for stationary accuracy, power cut-off, and simulated impact scenarios. To obtain precise data from GPS units, tests were performed with an electric scooter ridden in rural landscapes with clear skies
Desai, Elvis, Suway, Jeff, Engleman, Krystina, Vega, Henry
Technical Paper
Accuracy and Validation of 360-Degree Camera Use in Photogrammetry2022-01-100303/29/2022
Accident scene data obtained from photographs and videos are vital material for forensic analysts. They allow to precisely determine the orientation and location of evidence as seen on such images. For that reason, the term digital evidence was adopted and is commonly used among analysts in conjunction with retro-projection methods as an aid to reconstruct the events and inputs leading up to the investigation in question. Photogrammetry is a retro-projection method commonly used by analysts to match scene photographs with calibrated control points obtained from three-dimensional point cloud data collected at the subject site and visualized on the scene images. From this merger, the photographs allow for the determination of the point at which the camera was positioned that took the subject image. In general, the point cloud data allows for increased accuracy during the photogrammetry process. Video footage obtained from the scenes can be exported as frames and then used in the same
Morales, Roberto C.
Technical Paper
Geospatial Accuracy of Small Unmanned Airborne System Data in the Coastal EnvironmentTBMG-3433005/01/2019
The purpose of this study was to assess the ability of commonly available COTS software to produce geometrically accurate orthometric mosaics and terrain models from low-altitude UAS imagery.
Magazine Article
Geospatial Accuracy of Small Unmanned Airborne System Data in the Coastal Environment19AERP05_0605/01/2019
Determining the performance of image processing software could lead to better data collection strategy. Army Engineer Research and Development Center, Alexandria, Virginia The purpose of this study was to assess the ability of commonly available COTS software to produce geometrically accurate orthometric mosaics and terrain models from low-altitude UAS imagery. The coastal zone is a dynamic environment that requires temporal monitoring from flexible remote sensing tools. Changing weather, winds, and tides introduce difficulties when attempting to use sensors that are constrained by schedule to include satellite overflight or aircraft with hard collection dates and times. However, these collection requirements are well suited for small unmanned airborne system (UAS) platforms that can be deployed and made operational with minimal notice. Additionally, the low collection altitude, combined with short focal length imagers (often integrated into these small UAS platforms) are capable of
Magazine Article
The Placement of Digitized Objects in a Point Cloud as a Photogrammetric Technique09-06-02-000708/08/2018
The frequency of video-capturing collision events from surveillance systems are increasing in reconstruction analyses. The video that has been provided to the investigator may not always include a clear perspective of the relevant area of interest. For example, surveillance video of an incident may have captured a pre- or post-incident perspective that, while failing to capture the precise moment when the pedestrian was struck by a vehicle, still contains valuable information that can be used to assist in reconstructing the incident. When surveillance video is received, a quick and efficient technique to place the subject object or objects into a three-dimensional environment with a known rate of error would add value to the investigation. In addition, once the objects have been placed into the three-dimensional environment, the investigator would then be able to observe the physical evidence and environment from any perspective, including viewing and measuring what cannot be seen in
Harrington, Shawn, Lebak, Gabriel
Journal Article
The Accuracy of an Optimized, Practical Close-Range Photogrammetry Method for Vehicular Modeling2016-01-146204/05/2016
Three targeted vehicles of varying size were measured using an optimized, practical photogrammetry technique and the results were compared to measurements acquired via total station. The photogrammetry method included the use of a field-calibrated DSLR camera equipped with a fixed 20 mm lens, retroreflective targets sized for vehicular modeling, and a CNC-machined scale bar. Eight photographs were taken from proper angles and processed using a commercially available photogrammetry package. This data was merged with the total station data using a cloud-to-cloud registration process for point-to-point comparison of positional data. The average residual between corresponding photogrammetry and total station points was 1.7 mm (N = 258, SD = 0.8 mm) with a 95% confidence limit of 3.1 mm. Considering this low residual, one of the sample vehicles was re-measured using a high accuracy FaroArm for comparison to the photogrammetry technique. The average residual between corresponding
Cheng, Mu-Hua, Peck, Louis R.
Journal Article
Determining Position and Speed through Pixel Tracking and 2D Coordinate Transformation in a 3D Environment2016-01-147804/05/2016
This paper presents a methodology for determining the position and speed of objects such as vehicles, pedestrians, or cyclists that are visible in video footage captured with only one camera. Objects are tracked in the video footage based on the change in pixels that represent the object moving. Commercially available programs such as PFTracktm and Adobe After Effectstm contain automated pixel tracking features that record the position of the pixel, over time, two dimensionally using the video’s resolution as a Cartesian coordinate system. The coordinate data of the pixel over time can then be transformed to three dimensional data by ray tracing the pixel coordinates onto three dimensional geometry of the same scene that is visible in the video footage background. This paper explains the automated process of first tracking pixels in the video footage, and then remapping the 2D coordinates onto three dimensional geometry using previously published projection mapping and photogrammetry
Neale, William T., Hessel, David, Koch, Daniel
Technical Paper
Accuracy of SUAS Photogrammetry for Use in Accident Scene Diagramming2015-01-142604/14/2015
Photogrammetry from images captured by terrestrial cameras and manned aircraft has been used for many years to model objects, create scale diagrams and measure distances for use in traffic accident investigation and reconstruction. Due to increasing capability and availability, Unmanned Aircraft Systems (UAS), including small UAS (SUAS), are becoming a valuable, cost effective tool for collecting aerial images for photogrammetric analysis. The metric accuracy of scale accident scene diagrams created from SUAS imagery has yet to be compared to conventional measurement methods, such as total station and laser measurement systems, which are widely used by public safety officials and private consultants. For this study, two different SUAS were used to collect aerial imagery for photogrammetric processing using PhotoModeler software. A high-resolution consumer grade camera as well as a lower-resolution integrated camera was used as payload to determine the effect of camera resolution on the
Jurkofsky, Drew A.
Journal Article
Estimating Foreign-Object- Debris Density From Photogrammetry DataTBMG-1614404/01/2013
Within the first few seconds after launch of STS-124, debris traveling vertically near the vehicle was captured on two 16-mm film cameras surrounding the launch pad. One particular piece of debris caught the attention of engineers investigating the release of the flame trench fire bricks. The question to be answered was if the debris was a fire brick, and if it represented the first bricks that were ejected from the flame trench wall, or was the object one of the pieces of debris normally ejected from the vehicle during launch. If it was typical launch debris, such as SRB throat plug foam, why was it traveling vertically and parallel to the vehicle during launch, instead of following its normal trajectory, flying horizontally toward the north perimeter fence?
Magazine Article
Photogrammetric Measurement Error Associated with Lens Distortion2011-01-028604/12/2011
All camera lenses contain optical aberrations as a result of the design and manufacturing processes. Lens aberrations cause distortion of the resulting image captured on film or a sensor. This distortion is inherent in all lenses because of the shape required to project the image onto film or a sensor, the materials that make up the lens, and the configuration of lenses to achieve varying focal lengths and other photographic effects. The distortion associated with lenses can cause errors to be introduced when photogrammetric techniques are used to analyze photographs of accidents scenes to determine position, scale, length and other characteristics of evidence in a photograph. This paper evaluates how lens distortion can affect images, and how photogrammetrically measuring a distorted image can result in measurement errors. Lens distortion from a variety of cameras is analyzed, and the ultimate effect that this distortion has on the image is evaluated, with a discussion on the overall
Neale, William T., Hessel, David, Terpstra, Toby
Technical Paper
Measuring Positions of Objects Using Two or More CamerasTBMG-283906/01/2008
An improved method of computing positions of objects from digitized images acquired by two or more cameras (see figure) has been developed for use in tracking debris shed by a spacecraft during and shortly after launch. The method is also readily adaptable to such applications as (1) tracking moving and possibly interacting objects in other settings in order to determine causes of accidents and (2) measuring positions of stationary objects, as in surveying. Images acquired by cameras fixed to the ground and/or cameras mounted on tracking telescopes can be used in this method.
Magazine Article
Measuring Positions of Objects Using Two or More CamerasTBMG-TB-00283905/27/2008
This method could determine the causes of accidents. An improved method of computing positions of objects from digitized images acquired by two or more cameras (see figure) has been developed for use in tracking debris shed by a spacecraft during and shortly after launch. The method is also readily adaptable to such applications as (1) tracking moving and possibly interacting objects in other settings in order to determine causes of accidents and (2) measuring positions of stationary objects, as in surveying. Images acquired by cameras fixed to the ground and/or cameras mounted on tracking telescopes can be used in this method.
Magazine Article
Quantitative Assessment of Cosmetic and Structural Quality in Automotive Outer Body Panels Using ARAMIS Stereo Photogrammetry System2005-01-058804/11/2005
The methodology described enables high accuracy in the measurement of static and dynamic stiffness and dent resistance. Among the parameters being evaluated are: stiffness and dent resistance of the automotive outer body assembled panels – under both static and dynamic loading and the effect of the stiffening features in the panel shape, upon its deformation characteristics under dynamic excitation and dynamic wave propagation following slow projectile impact. This methodology will help part and process designers to correctly position and manufacture outer and inner body features like door handle embossment shape and location, feature lines, lamp and mirror embossments, hemming lines and side bar locations. Measurements are carried out using the stereo photogrammetry system ARAMIS – a fast and cost effective tool with a high accuracy of displacement measurement in both static and dynamic conditions. Measurements were performed in real time related to the phase of elastic wave generated
Sikorski, Andrzej, Grabovskyy, Vitaliy
Technical Paper
A Method for Improving the Accuracy of Standard Stereo Photogrammetry When Using Small Subtended Angles2005-01-075104/11/2005
In stereo photogrammetry, the accuracy of calculating the location of a point in space, decreases as the angle between the two cameras decreases. For vehicle crash testing, the need for accurate 3D data conflicts with the need for flexible positioning of the cameras, to enable unobstructed views of the targets inside the vehicle throughout the impact event. This paper discusses a method for increasing the quantity and quality of film analysis data when small subtended angles are used. The method uses the 3D information developed through triangulation of two cameras as input to a single camera analysis.
Byers, Lynn C., Slon, Christopher M.
Technical Paper
A Video Tracking Photogrammetry Technique to Survey Roadways for Accident Reconstruction2004-01-122103/08/2004
When reconstructing vehicle accidents, it is often important to record the accident scene roadway geometry. Survey techniques such as the plane surveying method1 and the coordinate and triangulation method2, have been the most widely used recording methods and are generally accepted in the industry. This paper proposes to introduce video tracking photogrammetry as a new tool in gathering accident scene and roadway data. The video tracking photogrammetry technique makes it possible to use accident scene video to record the accident scene geometry by incorporating photogrammetry principles. This paper will also report on the accuracy of the video tracking photogrammetry technique and discuss its strengths and limitations.
Neale, William T.C., Fenton, Steve, McFadden, Scott, Rose, Nathan A.
Technical Paper
Human Cervical Motion Segment Flexibility and Facet Capsular Ligament Strain Under Combined Posterior Shear, Extension and Axial Compression2000-01-SC1211/01/2000
The cervical facet capsular ligaments are thought to be an important anatomical site of whiplash injury, although the mechanism by which these structures may be injured during whiplash remains unclear. The purpose of this study was to quantify the intervertebral flexibility and maximum principal strain in the facet capsular ligament under combined shear, bending and compressive loads similar to those which occur during whiplash loading. Two motion segments (C3-4 and C5-6) from seven female donors (50 ± P 10 years) were exposed to quasi-static posterior shear loads of 135 N applied to the superior vertebra on four occasions while under compressive axial preloads of 0 N, 45 N, 197 N and 325 N. Vertebral body motions and the full Lagrangian strain field in the right facet capsular ligament were measured using stereophotogrammetry. After flexibility testing, the right facet joint of each motion segment was isolated and failed in posterior shear. Differences in the kinematic response of the
Siegmund, Gunter, Myers, Barry S.
Technical Paper
An Evaluation of Rectified Bitmap 2D Photogrammetry with PC-Rect97095202/24/1997
Without good-quality measurements taken at the time of an accident the analyst is faced with the need to extract measurement data from incident scene photographs. This paper discusses the history and development of the mathematical model for two-dimensional (2D) single exposure analytical photogrammetry, presents the software PC-Rect, and compares the analytical results obtained with PC-Rect to survey results. The sensitivity of the analytical results to the variation in such parameters as subject distance, camera height, digital photograph resolution, and bitmap density is discussed. The concept of using the directly rectified scanned photograph in the reconstruction task is introduced, and the utility of performing the dynamic simulation directly on the rectified photograph is discussed.
Cliff, William E., Maclnnis, Duane D., Switzer, David A.
Technical Paper
Band Information Reconstruction from a Single Photo - A Superimposed Method96089302/01/1996
To interpret the information on a 2-D image of a 3-D world in order to determine the displacement of the 3-D objects portrayed in the image, this study superimposes the 2-D image with another photo which is taken from the same site and includes some additional objects with well defined dimensions. In this synthetic image, those added objects serve as a datum; mathematical functions are then used to evaluate the true size of any object in the image. In the computerized photogrammetry method proposed in this study, other than the need for an additional photo with known-dimension poles in it and the required adjustment on the direction and distance of this photo to suit for the target one, there is no extra field measurement necessary, nor is any adjustment introduced in the computational process.
Wang, Ying-Wei, Ting, Kuo-Liang, Kuo, Yo-Chung
Technical Paper
Digital Rectification of Reconstruction Photographs96104902/01/1996
Computerized photogrammetry as it relates to accident reconstruction is well known and has been documented by a number of researchers. Planar photogrammetry algorithms have been demonstrated to be adequate for a large number of situations involved in reconstruction. These algorithms all transform individual points in the photographic image plane to a plane associated with the objects of interest. The points are then presented in either tabular and/or line drawing form. This paper presents a planar method of rectifying an entire photographic image to the horizontal plane, so that the resulting rectified image can be viewed from directly overhead or from any other perspective. The method has specific advantages in analyzing accident scene photos containing skid marks, gouges, and other evidence, without the inconvenience of perspective distortion. The method also dramatically increases the volume of data which can be conveniently analyzed. The stages of the process are discussed and
Pepe, Michael D., Grayson, Eric, McClary, Andrew
Technical Paper
The Use of Photogrammetry and Video Films in the Evaluation of Passenger Compartment Measurement and Occupant-Vehicle Contacts95023902/01/1995
The evaluation of new safety systems in cars is based not only of the accident severity and type, but also on the behaviour of the interior of the vehicle in terms of intrusion and other interior deformations. It is also essential that contact points can be found explaining injuries to occupants and also showing possible restraint use. It is however complicated to measure interior deformations, especially in three dimensions and with non-specialists going out to the crashed car. It is also complicated to find contact points for non-specialists not always knowing the injuries of the occupants at the time of the interior inspection of a crashed car. In this paper, methods for distant evaluation of crashed car interiors with photogrammetrical and video cameras allowing three dimensional measurements and the possibility to judge interior contacts. With such methods, data collection can be performed by non-specialists with a high quality of the analysis. The methods are presented with
Kullgren, A., Lie, A.
Technical Paper
Photogrammetry and Accident Reconstruction: Experimental Results94092503/01/1994
A controlled experiment involving road marks was conducted to compare various photogrammetry practices currently in use in the accident investigation community. The experimental controls and results are discussed for three variations of one 2-D scheme and for six 3-D photogrammetric schemes applied to a similar set of road marks and points. For measurements related to the most frequent issues in traffic accidents, all of the methods are capable of providing usable data. The experimental photographs and corresponding data represent a reference set for developing skills and for comparison with other photogrammetry schemes.
Tumbas, Nicholas S., Kinney, J. Rolly, Smith, Gregory C.
Technical Paper
Accuracy of Three-Dimensional Photogrammetry as Established by Controlled Field Tests93066203/01/1993
Photogrammetry is the science of obtaining spatial information from photographs given a set of key reference points. Vehicular accident reconstruction frequently requires using the photogrammetric process to obtain dimensions of such items as skid mark length, vehicle rest positions, or depth of vehicle crush. This paper briefly describes the generalized three-dimensional photogrammetric process. Findings are then presented which show the accuracy of this process when applied to simulated reconstruction situations involving skid marks and vehicle crush. Specifically, three sets of photographs of simulated skid marks and one of vehicle crush were analyzed photogrammetrically. The results were then compared to a blind set of survey data which was revealed only after the photogrammetry calculations had been completed. The comparison between the survey data and photogrammetry calculations are presented in graphical form.
Pepe, Michael D., Sobek, James S., Zimmerman, D. Allen
Technical Paper
Adapting Three-Dimensional Animation Software for Photo grammetry Calculations93090403/01/1993
A new method for computer-based photogrammetry in accident reconstruction is presented. CAD software is used to produce three-dimensional models of the site, vehicles, and other objects important in the incident. Objects of known configuration are incorporated into the scene model, and a perspective view is created that corresponds to the photograph. Then the objects of unknown position are added, and these are translated and rotated until they match the photograph. The result is a three-dimensional computer model of the site geometry, from which positional information may be extracted by examining the top, front, and side orthographic views.
Campbell, A. T., Friedrich, Richard L.
Technical Paper
A Development of Statistical Human Back Contour Model for Backrest Comfort Evaluation93011403/01/1993
First, this paper describes a measurement of the human back-backrest interface contours and a reduction procedure of the measured contours to reconstruct the statistical back contours of American 50 and 95-percentile male. Second, the paper illustrates the difference of the back contour between the statistical male drivers and SAE 3-D Manikin. Finally, the advantage of using the back contour model in experiment is given. The AM 50 back contour model was used as a loader to obtain the backrest pressure distribution and proved an excellent tool for backrest comfort evaluation.
Nakaya, Hirosuke, Okiyama, Hiroshi
Technical Paper
Computer-Aided 3-D Surface Reconstruction During High Speed Crush Events91032002/01/1991
A system which can remotely measure detailed deformations of vehicle structures during crush events was developed. The system uses ordinary video or 16 mm high speed movie to capture the crush event. This information is digitized and analyzed using personal computers to perform photogrammetric manipulations which yield accurate surface geometries. The output is useful for comparison to computer simulations. This paper presents preliminary results regarding the accuracy of this system.
Karvelis, Albert V., Rogers, Michael W., Anderson, Carl E., Liubinskas, Aldis
Technical Paper
Field Application of Photogrammetric Analysis Techniques: Applications of the FOTOGRAM Program86141811/01/1986
This paper describes how a photogrammetric analysis computer program entitled FOTOGRAM™ is used with a personal computer. The FOTOGRAM program was described in a paper entitled “Photogrammetric Analysis Using the Personal Computer” by Brelin, Cichowski, and Holcomo.(1)* The technique described herein utilizes field examples to show how skid mark data are extracted from photographs using manual as well as electronic digitization methods. The digitized photographic data are then converted with the FOTOGRAM computer program into ‘real-world’ data points that may be plotted on a collision scene schematic. Thus, the actual path of the vehicle during skidding and/or tire marking can be determined for use in reconstructing the accident.
Grimes, Wesley D., Culley, Charles H., Cromack, J. Robert
Technical Paper
TRANS4 - A Traffic Accident Photogrammetric System, Description of the System and Its Inherent Errors86141710/01/1986
A photogrammetric transformation is presented, which maps photograph image points to the location of the same points on a nominally plane real surface. The transformation uses 4 base points on the real surface that have known locations and is implemented by an interactive program entitled TRANS4; which runs on MS/PC DOS microcomputer systems. The program addresses three of the five major tasks in the process of extracting geometric data from photographs of a traffic accident site and makes the method a realistic option for investigators. The two other tasks are also discussed. The character and relative magnitude of several errors associated with the transformation are discussed, along with techniques for managing the errors.
Kinney, J. Rolly, Magedanz, Bill
Technical Paper
The Application of Photogrammetry to Accident Reconstruction86142210/01/1986
Accident investigation involves the collection of relevant data from many sources. Frequently, information exists in the form of accident photographs of objects that are no longer available for examination or direct measurement. The use of close-range photogrammetry can be an effective tool in the utilization of these photographs. In this paper, a case study accident investigation is described where stereo photogrammetry was applied to develop information for further analysis and testing.
Breen, Kevin C., Anderson, Carl E.
Technical Paper
Photogrammetric Analysis Using the Personal Computer86141610/01/1986
“FotoGram” is a two dimensional photogrammetry software package developed by General Motors Corporation. It generates a transformation matrix from the input reference data which best represents a given surface and “transforms” the selected points into a plan view. The general usage of the “FotoGram” software in accident reconstruction is presented along with various methods of reference point measurement and placement.
Brelin, Janet M., Cichowski, William G., Holcomb, Michael P.
Technical Paper
Photogrammetric Deformation Measurement of Crash Vehicles86020702/24/1986
The determination of the deformation of objects in crash test is of considerable significance for the evaluation of the crash test results. The data obtained allow to understand the deformation mechanisms, which in turn serve as a basis for potential changes to the vehicle. In the absence of photogrammetric measurement devices, deformation data must be acquired by means of complicated measurements using a measuring platform, a method which hampers or delays the evaluation of crash test results. Until recently, the high expenditure involved in deformation analyses made it advisable to evaluate only a small number of selected tests. By means of the photogrammetric deformation measurement, each crash test can be recorded.
Wester-Ebbinghaus, Wilfried, Wezel, Ulrich E.
Technical Paper
Computer Assisted Single-View Photogrammetry for Accident Scene Documentation85006702/25/1985
Accurate documentation of traffic accidents is a prerequisite for accident research as well as traffic jurisdiction. As an important part of accident documentation, stereo-photogrammetry is recognised to be an excellent tool for providing accurate and complete scaled maps of accident scenes. However, due to its relatively high expense, it is usually only applied in cases of severe accidents. In contrast, single-view photogrammetry which is based on photographs taken with “non-metric” cameras and on on-the-job calibration requires little installation at the accident scene and provides adequate accuracy, because camera calibration and plotting of scaled maps can be performed by making use of computer-assisted image analysis. As the method basically consists in a simple perspective rectification single-view photogrammetry as such is restricted to plane accident sites. In this paper the method is demonstrated and its accuracy discussed. ACCURATE AND COMPLETE documentation of traffic
Niederer, Peter, Birchler, Bernhard, Mesqui, François, Lehareinger, Yves
Technical Paper
Cinephotogrammetrical Study of Porcine Thoracic Response to Belt Applied Load in Frontal Impact-Comparison Between Living and Dead Subjects81101510/01/1981
The mechanical response and the injury pattern of pig thorax submitted to belt loading conditions were compared for living and dead subjects. The absolute deflexion and the resultant force were computed from cinephotogrammetric data. The results indicate that dead are stiffer by 80 % than living subjects. The visceral injury rate is higher in the living population. The skeletal injury rate is identical for both populations but injury patterns are different. Correlations were obtained in the living sample particularly between injury levels and deflexion, force and aortic pressure. With dead subjects, only one correlation was obtained between injury level and deflexion.
Verriest, J. P., Chapon, A., Trauchessec, R.
Technical Paper
Simplified Three-Dimensional Protogrammetric Analysis of Moving Bodies73027802/01/1973
Accurate values of velocity and acceleration of a point on an impacting vehicle are determined by Wayne State University (WSU) personnel using a simple but flexible three-dimensional photogrammetric technique requiring little site preparation and no knowledge of the quantitative optical properties of the cameras. A computer program was developed to locate the point in space as it moves and to calculate its position, velocity and acceleration vectors as functions of time. Curve smoothing is accomplished in the computer program by means of a special algorithm designed to reduce the effects of random measurement errors, which are greatly magnified in the calculation of velocity and acceleration.
Kay, I. W., Zobel, E. C.
Technical Paper
Aerial Photography Operations in the Coast and Geodetic Survey67023202/01/1967
Through the exploitation of color, infrared, and panchromatic aerial films, the Coast and Geodetic Survey has developed aerial photography skills and procedures that have removed much of the hazardous and back-breaking work from charting shoreline and locating landmarks and aids to nautical navigation. It has extended these techniques to aeronautical and airport obstruction charting, and more recently has applied photogrammetric principles to mapping boundaries, making crustal movement surveys, measuring tidal currents, and for extending horizontal control.
Moran, Lt. Francis D.
Technical Paper
Photogrammetry and Computers for Numerical Control66035502/01/1966
Photogrammetry as a measuring technique for practical application in the automotive field shows great promise. The potential of this technique in order to establish an error-free, geometrically defined, spatial mathematical automobile car body formated for subsequent use in an electronic computer program is described. The major problems encountered in the development of this system for the automotive application intended have been overcome to a large extent, and future studies are continuing to effect further improvements with regard to achieving increased reliability and flexibility and higher production rates.
Wright, Marshall S., Gherardi, E. M.
Technical Paper
Photogrammetry and Analysis of Digital MediaC1712
This course teaches the theory and techniques for using digital media, including correctly processing raw video and photographs, correcting for lens distortion, and using photogrammetric techniques to convert the information in digital media to usable scaled three-dimensional data to better understand how crashes occurred and in analyzing physical evidence. Hands-on training using actual case studies and a variety of software titles such as 3D Studio, Max, PTLens, Photoshop, and PFTrack will introduce the students to the latest techniques.
and, Toby, Hashemian, Alireza
Instructor Led
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