Remote sensing and GIS techniques are useful tools for civil engineering projects. There are several models that can be used to represent the shape of the Earth, including flat, spherical, and ellipsoidal models. The ellipsoidal model is needed for accurate measurements over long distances. A geodetic datum defines the parameters of the reference ellipsoid and the orientation of the coordinate system grid. Common datums include NAD27 and NAD83, and transformations allow conversion between them. Map projections, such as Mercator and UTM, are used to represent the 3D Earth on a 2D surface, inevitably distorting some spatial properties like shape, area, or distance.
1) The document discusses various coordinate systems used in photogrammetry including pixel, image, image space, and ground coordinate systems.
2) It also covers topics like interior orientation parameters (principal point, focal length), exterior orientation parameters (position and rotation angles), and two-dimensional coordinate transformations.
3) The relationships between the image, camera, and ground coordinates are defined using these parameters and coordinate systems to allow for mapping between the three domains.
Photogrammetry is the technique of obtaining reliable spatial information about physical objects through analyzing photographs. It involves taking overlapping aerial photographs from an elevated position and processing them using software to extract 3D spatial data and produce accurate maps, models and measurements. The key outputs of photogrammetry include digital elevation models (DEMs), digital terrain models (DTMs), contour maps, orthophotos and 3D city models. Photogrammetry provides precise, cost-effective representations of geographic features and terrain.
SURVEYING - Photogrammetry (CE 115) Lec2 By Afia Narzis Spring 2016PIYAL Bhuiyan
Photogrammetry is a method of surveying that uses photographs to prepare maps and plans. There are two main types: terrestrial photogrammetry uses ground-based photos, while aerial photogrammetry uses photos taken from aircraft. Aerial photogrammetry involves advanced planning, flying missions to take overlapping vertical photos with specialized cameras, conducting ground control surveys, and compiling the photos into maps. It is used for tasks like topographic mapping, infrastructure planning, and military surveillance.
This document discusses aerial photogrammetry and provides definitions of key terms. It describes how aerial photographs are taken from aircraft and used to create topographic maps. The process involves establishing ground control points, planning flights and photography with proper overlap, interpreting photographs, using stereoscopes to view overlapping image pairs in 3D, and constructing maps through cartography. Precise measurement of ground coordinates is enabled through analyzing parallax differences between corresponding points in stereoscopic image pairs.
- Photogrammetry is the science of obtaining reliable information from photographic images. It involves recording, measuring, and interpreting images and electromagnetic radiation.
- There are two main types: terrestrial photogrammetry which uses ground-based photos, and aerial photogrammetry which uses photos taken from aircraft.
- Vertical aerial photos are easier to interpret but cover less ground, while oblique photos cover more area but are harder to interpret. Photogrammetry is used to create maps and 3D models.
Photogrammetry is the science of obtaining accurate measurements through photographs. There are several types of photogrammetry depending on the camera position, including aerial photogrammetry using cameras mounted on aircraft, terrestrial photogrammetry using ground-based cameras, and space photogrammetry using cameras on satellites. The process involves taking photographs, processing the images, and measuring the photographs to produce outputs like topographic maps. Aerial photography is commonly used to create maps, monitor land usage and geology, and support applications in fields like military intelligence and mining. The scale of an aerial photograph varies based on the terrain elevation and camera parameters like focal length and flight altitude.
Remote sensing and GIS techniques are useful tools for civil engineering projects. There are several models that can be used to represent the shape of the Earth, including flat, spherical, and ellipsoidal models. The ellipsoidal model is needed for accurate measurements over long distances. A geodetic datum defines the parameters of the reference ellipsoid and the orientation of the coordinate system grid. Common datums include NAD27 and NAD83, and transformations allow conversion between them. Map projections, such as Mercator and UTM, are used to represent the 3D Earth on a 2D surface, inevitably distorting some spatial properties like shape, area, or distance.
1) The document discusses various coordinate systems used in photogrammetry including pixel, image, image space, and ground coordinate systems.
2) It also covers topics like interior orientation parameters (principal point, focal length), exterior orientation parameters (position and rotation angles), and two-dimensional coordinate transformations.
3) The relationships between the image, camera, and ground coordinates are defined using these parameters and coordinate systems to allow for mapping between the three domains.
Photogrammetry is the technique of obtaining reliable spatial information about physical objects through analyzing photographs. It involves taking overlapping aerial photographs from an elevated position and processing them using software to extract 3D spatial data and produce accurate maps, models and measurements. The key outputs of photogrammetry include digital elevation models (DEMs), digital terrain models (DTMs), contour maps, orthophotos and 3D city models. Photogrammetry provides precise, cost-effective representations of geographic features and terrain.
SURVEYING - Photogrammetry (CE 115) Lec2 By Afia Narzis Spring 2016PIYAL Bhuiyan
Photogrammetry is a method of surveying that uses photographs to prepare maps and plans. There are two main types: terrestrial photogrammetry uses ground-based photos, while aerial photogrammetry uses photos taken from aircraft. Aerial photogrammetry involves advanced planning, flying missions to take overlapping vertical photos with specialized cameras, conducting ground control surveys, and compiling the photos into maps. It is used for tasks like topographic mapping, infrastructure planning, and military surveillance.
This document discusses aerial photogrammetry and provides definitions of key terms. It describes how aerial photographs are taken from aircraft and used to create topographic maps. The process involves establishing ground control points, planning flights and photography with proper overlap, interpreting photographs, using stereoscopes to view overlapping image pairs in 3D, and constructing maps through cartography. Precise measurement of ground coordinates is enabled through analyzing parallax differences between corresponding points in stereoscopic image pairs.
- Photogrammetry is the science of obtaining reliable information from photographic images. It involves recording, measuring, and interpreting images and electromagnetic radiation.
- There are two main types: terrestrial photogrammetry which uses ground-based photos, and aerial photogrammetry which uses photos taken from aircraft.
- Vertical aerial photos are easier to interpret but cover less ground, while oblique photos cover more area but are harder to interpret. Photogrammetry is used to create maps and 3D models.
Photogrammetry is the science of obtaining accurate measurements through photographs. There are several types of photogrammetry depending on the camera position, including aerial photogrammetry using cameras mounted on aircraft, terrestrial photogrammetry using ground-based cameras, and space photogrammetry using cameras on satellites. The process involves taking photographs, processing the images, and measuring the photographs to produce outputs like topographic maps. Aerial photography is commonly used to create maps, monitor land usage and geology, and support applications in fields like military intelligence and mining. The scale of an aerial photograph varies based on the terrain elevation and camera parameters like focal length and flight altitude.
This document summarizes the principles of photogrammetry. It discusses the basic elements of photogrammetry including obtaining quantitative information from aerial photographs. It covers topics such as photographic scale, horizontal ground coordinates, relief displacement, exterior orientation of tilted photographs, stereoscopic vision, and the geometry of aerial stereophotographs. The purpose is to provide background information and references to support standards and guidelines for photogrammetric mapping.
This document discusses the basic principles of photogrammetry. It defines photogrammetry as obtaining spatial measurements and geometrically reliable products from photographs. It describes the different types of analysis procedures and photogrammetric operations used, from simple to sophisticated digital techniques. It outlines common photogrammetric activities like producing maps, determining heights and elevations, and preparing flight plans. It also details the geometric characteristics of aerial photographs, elements, scales, distortions like relief displacement and parallax.
This document discusses various techniques for analyzing aerial photographs, including:
- Calculating the scale of photographs based on known distances and camera specifications. Scale expresses the ratio of distances on the photo to distances on the ground.
- Determining the heights of objects visible in photos using relief displacement, which measures the difference in an object's appearance between the top and bottom due to perspective.
- Planning flight paths to ensure adequate overlap between consecutive aerial photos for stereoscopic analysis and 3D modeling.
- Using a stereoscope to merge overlapping photo pairs and perceive depth and parallax differences between matching points in the stereo pair.
This document provides an overview of photogrammetry, including a brief history of aerial photography, definitions of key terms, and descriptions of different types of photogrammetry and imaging. It discusses the general photogrammetric process and products that can be created. Specific topics covered include the development of aerial photography from the 1850s onwards, definitions of photogrammetry, close range, terrestrial, aerial, and space photogrammetry, types of aerial images, photogrammetric mapping techniques, and historical photogrammetric plotting instruments.
Photogrammetry is the science of obtaining reliable measurements from photographs. There are three main techniques: aerial, using vertically downward photos from planes or satellites; terrestrial, using horizontal photos on the ground; and industrial, adapting terrestrial techniques to small areas. Aerial photos are used for topographic mapping, cadastral plans, land use maps, and hydrographic charts. Stereo plotters allow precise 3D measurement and analysis from stereo photo pairs. Photogrammetry has many applications beyond traditional surveying, including traffic accident reconstruction, medical imaging, and analysis of surface movement.
Aerial surveying technology is utilized in a wide range of fields throughout the world. These range from the creation of maps, to terrain analysis and research (rivers, soil erosion, coasts, etc.), urban planning, road planning (roads, rails, etc.), and vegetation research (forests, agriculture, lakes and marshland, etc.).
This document discusses stereoscopic vision and its use in aerial photo interpretation. Stereoscopic vision involves using binocular vision to view overlapping photos from two camera positions to perceive 3D depth. Various stereoscopes can be used, like lens stereoscopes suitable for field use. Key measurements for determining object heights from stereo pairs include the average photo base length and differential parallax. Precise stereoplotters and software can digitally recreate stereo models for mapping. Orthophotos rectify photos to show objects in true planimetric positions.
This document discusses digital photogrammetry. It begins by explaining that digital photogrammetry uses digital images that are stored and processed on a computer, rather than hard copy photos. These digital images can come from satellites, airplanes, or cameras. The document then discusses some applications of digital photogrammetry like topographic mapping and creating orthophotos, digital elevation models (DEMs), and virtual landscapes. It also notes that nadir imagery and image overlap are needed to provide 3D information. Finally, the document lists some common products of digital photogrammetry such as maps, DEMs, and virtual landscapes.
Remote sensing began with aerial photography in the 1800s. It involves collecting data about the Earth's surface from a distance using electromagnetic sensors. Vertical aerial photographs are important for remote sensing as they have minimal distortion and can be used to take measurements. Photogrammetry allows calculating scale and measurements from aerial photos using factors like focal length and aircraft height. Stereopairs of aerial photos enable measuring terrain height differences through parallax, similar to how human binocular vision perceives depth.
This document discusses the history and fundamentals of digital photogrammetry. It describes the evolution from analog to digital photogrammetry and how computer hardware and software have advanced the discipline. The key aspects covered include digital image characteristics like resolution, sampling and quantization. It also outlines common image processing operations, hardware requirements, and software functions needed for digital photogrammetry like image matching, rectification and visualization.
Photogrammetry is the science of obtaining information about physical objects through images. It involves mapping terrain from aerial photographs. Key points:
- Aerial photography is the most common and effective method for large-scale topographic mapping. Photogrammetry is used by the U.S. Geological Survey and for various applications like engineering projects.
- Precise 3D measurements can be made from stereo pairs of photographs using a stereoplotter. Control points are also needed from field surveys.
- Factors like terrain, camera focal length, flying height, overlap, and scale must be considered to plan a photogrammetry project. Proper planning is required to efficiently capture needed imagery and produce accurate maps.
This document discusses tilted aerial photographs. It begins by defining tilted photographs as those where the camera axis is slightly angled from vertical when capturing the image, usually by less than 3 degrees. It then introduces exterior orientation parameters (EOPs) that define the spatial position and angular orientation of each photograph. Two systems for defining angular orientation are described: tilt-swing-azimuth and omega-phi-kappa. Perspective projection and how it relates 3D objects to their 2D image is also overviewed. The remainder of the document discusses how to calculate scale on tilted photographs based on factors like tilt, swing, height, and elevation.
Photogrammetry is a technique for measuring objects from photographs. It involves taking aerial photographs from an aircraft or ground positions and using the photos to indirectly measure objects and map terrain. Key steps in the photogrammetric process include image acquisition, establishing ground control points, aerial triangulation to determine photo orientation, stereo compilation to map features, and quality control checks of the final maps. Photogrammetry is useful for mapping large or inaccessible areas and produces digital products like orthophotos and terrain models. It is cost-effective for surveying wide areas but may not be suitable if higher accuracy is required or the scope of work is too small.
Photogrammetry - Space Resection by Collinearity EquationsAhmed Nassar
Space resection is commonly used to determine the exterior orientation parameters (which refers to position and orientation related to an exterior coordinate system) associated with one or more photos based on measurements of ground control points (GCPs). space resection is a nonlinear problem, existing methods involve linearization of the collinearity condition and the use of an iterative process to determine the final solution using the least-squares method. The process also requires initial approximate values of the unknown parameters, some of which must be estimated by another least-squares solution.
Trilateration and triangulation are surveying methods to establish horizontal control networks. Trilateration involves measuring the lengths of all three sides of triangles without measuring angles, while triangulation measures angles and the length of one base line. Both methods are used to determine coordinate positions through trigonometric computations. Triangulation networks can be classified based on their intended accuracy and purpose, from primary/first order for determining large areas to tertiary/third order for more detailed surveys.
This document summarizes the historical development of photogrammetry. It describes how photogrammetry evolved from early plane table photogrammetry between 1850-1900, to analog photogrammetry between 1900-1960, to analytical photogrammetry between 1960-present. It also discusses how digital photogrammetry is just beginning. The document provides background on important historical figures and developments in the field, including the first uses of aerial photography in the late 19th century and how photogrammetry has been used to create topographic maps since the 1840s.
This document summarizes the principles of photogrammetry. It discusses the basic elements of photogrammetry including obtaining quantitative information from aerial photographs. It covers topics such as photographic scale, horizontal ground coordinates, relief displacement, exterior orientation of tilted photographs, stereoscopic vision, and the geometry of aerial stereophotographs. The purpose is to provide background information and references to support standards and guidelines for photogrammetric mapping.
Phase Measuring Deflectometry (PMD) is a full-field 3D shape measurement technique that uses fringe pattern projection and analysis. It works by projecting fringe patterns onto a surface and capturing the reflected patterns with a camera. Fringe analysis is used to extract phase maps from the images, which provide slope information about the surface. Numerical integration of the slopes then allows reconstruction of the full 3D shape. PMD can measure both micro- and macro-scale shapes of specular surfaces. Various system configurations have been developed using different patterns, cameras, and additional sensors to address height-slope ambiguity issues and improve measurement accuracy and resolution. PMD is a low-cost, non-contact method suitable for industrial inspection and
This document summarizes the principles of photogrammetry. It discusses the basic elements of photogrammetry including obtaining quantitative information from aerial photographs. It covers topics such as photographic scale, horizontal ground coordinates, relief displacement, exterior orientation of tilted photographs, stereoscopic vision, and the geometry of aerial stereophotographs. The purpose is to provide background information and references to support standards and guidelines for photogrammetric mapping.
This document discusses the basic principles of photogrammetry. It defines photogrammetry as obtaining spatial measurements and geometrically reliable products from photographs. It describes the different types of analysis procedures and photogrammetric operations used, from simple to sophisticated digital techniques. It outlines common photogrammetric activities like producing maps, determining heights and elevations, and preparing flight plans. It also details the geometric characteristics of aerial photographs, elements, scales, distortions like relief displacement and parallax.
This document discusses various techniques for analyzing aerial photographs, including:
- Calculating the scale of photographs based on known distances and camera specifications. Scale expresses the ratio of distances on the photo to distances on the ground.
- Determining the heights of objects visible in photos using relief displacement, which measures the difference in an object's appearance between the top and bottom due to perspective.
- Planning flight paths to ensure adequate overlap between consecutive aerial photos for stereoscopic analysis and 3D modeling.
- Using a stereoscope to merge overlapping photo pairs and perceive depth and parallax differences between matching points in the stereo pair.
This document provides an overview of photogrammetry, including a brief history of aerial photography, definitions of key terms, and descriptions of different types of photogrammetry and imaging. It discusses the general photogrammetric process and products that can be created. Specific topics covered include the development of aerial photography from the 1850s onwards, definitions of photogrammetry, close range, terrestrial, aerial, and space photogrammetry, types of aerial images, photogrammetric mapping techniques, and historical photogrammetric plotting instruments.
Photogrammetry is the science of obtaining reliable measurements from photographs. There are three main techniques: aerial, using vertically downward photos from planes or satellites; terrestrial, using horizontal photos on the ground; and industrial, adapting terrestrial techniques to small areas. Aerial photos are used for topographic mapping, cadastral plans, land use maps, and hydrographic charts. Stereo plotters allow precise 3D measurement and analysis from stereo photo pairs. Photogrammetry has many applications beyond traditional surveying, including traffic accident reconstruction, medical imaging, and analysis of surface movement.
Aerial surveying technology is utilized in a wide range of fields throughout the world. These range from the creation of maps, to terrain analysis and research (rivers, soil erosion, coasts, etc.), urban planning, road planning (roads, rails, etc.), and vegetation research (forests, agriculture, lakes and marshland, etc.).
This document discusses stereoscopic vision and its use in aerial photo interpretation. Stereoscopic vision involves using binocular vision to view overlapping photos from two camera positions to perceive 3D depth. Various stereoscopes can be used, like lens stereoscopes suitable for field use. Key measurements for determining object heights from stereo pairs include the average photo base length and differential parallax. Precise stereoplotters and software can digitally recreate stereo models for mapping. Orthophotos rectify photos to show objects in true planimetric positions.
This document discusses digital photogrammetry. It begins by explaining that digital photogrammetry uses digital images that are stored and processed on a computer, rather than hard copy photos. These digital images can come from satellites, airplanes, or cameras. The document then discusses some applications of digital photogrammetry like topographic mapping and creating orthophotos, digital elevation models (DEMs), and virtual landscapes. It also notes that nadir imagery and image overlap are needed to provide 3D information. Finally, the document lists some common products of digital photogrammetry such as maps, DEMs, and virtual landscapes.
Remote sensing began with aerial photography in the 1800s. It involves collecting data about the Earth's surface from a distance using electromagnetic sensors. Vertical aerial photographs are important for remote sensing as they have minimal distortion and can be used to take measurements. Photogrammetry allows calculating scale and measurements from aerial photos using factors like focal length and aircraft height. Stereopairs of aerial photos enable measuring terrain height differences through parallax, similar to how human binocular vision perceives depth.
This document discusses the history and fundamentals of digital photogrammetry. It describes the evolution from analog to digital photogrammetry and how computer hardware and software have advanced the discipline. The key aspects covered include digital image characteristics like resolution, sampling and quantization. It also outlines common image processing operations, hardware requirements, and software functions needed for digital photogrammetry like image matching, rectification and visualization.
Photogrammetry is the science of obtaining information about physical objects through images. It involves mapping terrain from aerial photographs. Key points:
- Aerial photography is the most common and effective method for large-scale topographic mapping. Photogrammetry is used by the U.S. Geological Survey and for various applications like engineering projects.
- Precise 3D measurements can be made from stereo pairs of photographs using a stereoplotter. Control points are also needed from field surveys.
- Factors like terrain, camera focal length, flying height, overlap, and scale must be considered to plan a photogrammetry project. Proper planning is required to efficiently capture needed imagery and produce accurate maps.
This document discusses tilted aerial photographs. It begins by defining tilted photographs as those where the camera axis is slightly angled from vertical when capturing the image, usually by less than 3 degrees. It then introduces exterior orientation parameters (EOPs) that define the spatial position and angular orientation of each photograph. Two systems for defining angular orientation are described: tilt-swing-azimuth and omega-phi-kappa. Perspective projection and how it relates 3D objects to their 2D image is also overviewed. The remainder of the document discusses how to calculate scale on tilted photographs based on factors like tilt, swing, height, and elevation.
Photogrammetry is a technique for measuring objects from photographs. It involves taking aerial photographs from an aircraft or ground positions and using the photos to indirectly measure objects and map terrain. Key steps in the photogrammetric process include image acquisition, establishing ground control points, aerial triangulation to determine photo orientation, stereo compilation to map features, and quality control checks of the final maps. Photogrammetry is useful for mapping large or inaccessible areas and produces digital products like orthophotos and terrain models. It is cost-effective for surveying wide areas but may not be suitable if higher accuracy is required or the scope of work is too small.
Photogrammetry - Space Resection by Collinearity EquationsAhmed Nassar
Space resection is commonly used to determine the exterior orientation parameters (which refers to position and orientation related to an exterior coordinate system) associated with one or more photos based on measurements of ground control points (GCPs). space resection is a nonlinear problem, existing methods involve linearization of the collinearity condition and the use of an iterative process to determine the final solution using the least-squares method. The process also requires initial approximate values of the unknown parameters, some of which must be estimated by another least-squares solution.
Trilateration and triangulation are surveying methods to establish horizontal control networks. Trilateration involves measuring the lengths of all three sides of triangles without measuring angles, while triangulation measures angles and the length of one base line. Both methods are used to determine coordinate positions through trigonometric computations. Triangulation networks can be classified based on their intended accuracy and purpose, from primary/first order for determining large areas to tertiary/third order for more detailed surveys.
This document summarizes the historical development of photogrammetry. It describes how photogrammetry evolved from early plane table photogrammetry between 1850-1900, to analog photogrammetry between 1900-1960, to analytical photogrammetry between 1960-present. It also discusses how digital photogrammetry is just beginning. The document provides background on important historical figures and developments in the field, including the first uses of aerial photography in the late 19th century and how photogrammetry has been used to create topographic maps since the 1840s.
This document summarizes the principles of photogrammetry. It discusses the basic elements of photogrammetry including obtaining quantitative information from aerial photographs. It covers topics such as photographic scale, horizontal ground coordinates, relief displacement, exterior orientation of tilted photographs, stereoscopic vision, and the geometry of aerial stereophotographs. The purpose is to provide background information and references to support standards and guidelines for photogrammetric mapping.
Phase Measuring Deflectometry (PMD) is a full-field 3D shape measurement technique that uses fringe pattern projection and analysis. It works by projecting fringe patterns onto a surface and capturing the reflected patterns with a camera. Fringe analysis is used to extract phase maps from the images, which provide slope information about the surface. Numerical integration of the slopes then allows reconstruction of the full 3D shape. PMD can measure both micro- and macro-scale shapes of specular surfaces. Various system configurations have been developed using different patterns, cameras, and additional sensors to address height-slope ambiguity issues and improve measurement accuracy and resolution. PMD is a low-cost, non-contact method suitable for industrial inspection and
The document discusses the science and techniques of photogrammetry. Photogrammetry involves deriving precise 3D coordinates of points by viewing an area from two angles and mathematically intersecting converging lines in space. It allows for the creation of accurate 3D models, textured models, and dense surface models from photographs for applications like measurements, visualization, and meshing. The process involves camera calibration, data acquisition through stereo or all-directional photography, feature marking, orientation, idealization, point cloud generation, meshing, surface generation, texturing, and exporting the 3D data.
Determination of System Geometrical Parameters and Consistency between Scans ...David Scaduto
Digital breast tomosynthesis (DBT) requires precise knowledge of acquisition geometry for accurate image reconstruction. Further, image subtraction techniques employed in dual-energy contrast-enhanced tomosynthesis require that scans be performed under nearly identical geometrical conditions. A geometrical calibration algorithm is developed to investigate system geometry and geometrical consistency of image acquisition between consecutive digital breast tomosynthesis scans, according to requirements for dual-energy contrast-enhanced tomosynthesis. Investigation of geometrical accuracy and consistency on a prototype DBT unit reveals accurate angular measurement, but potentially clinically significant differences in acquisition angles between scans. Further, a slight gantry wobble is observed, suggesting the need for incorporation of gantry wobble into image reconstruction, or improvements to system hardware.
An algorithm to quantify the swelling by reconstructing 3D model of the face with stereo images is presented. We
analyzed the primary problems in computational stereo, which include correspondence and depth calculation. Work has been carried out to determine suitable methods for depth estimation and standardizing volume estimations. Finally we designed software for reconstructing 3D images from 2D stereo images, which was built on Matlab and Visual C++. Utilizing
techniques from multi-view geometry, a 3D model of the face was constructed and refined. An explicit analysis of the stereo
disparity calculation methods and filter elimination disparity estimation for increasing reliability of the disparity map was
used. Minimizing variability in position by using more precise positioning techniques and resources will increase the accuracy of this technique and is a focus for future work
This document discusses the principles and types of aerial photography. It covers the history of aerial photography from its beginnings in 1858 to modern developments. Key topics covered include the geometry of vertical aerial photographs, stereoscopy using overlapping photographs, distortions that can occur, and the centers (principal point, nadir, isocenter) of aerial photographs. Current uses of aerial photography include topographic mapping and remote sensing from aircraft and satellites.
1) Visual image interpretation of remote sensing data can be labor intensive and require extensive training, while digital analysis techniques allow for automated and more detailed spectral analysis.
2) Preprocessing steps such as geometric correction and radiometric calibration are often needed to remove distortions in remote sensing images before analysis.
3) Image enhancement techniques such as contrast stretching, filtering, and ratioing can increase separability of features by amplifying slight spectral differences in the data.
The aim of this paper is to present the essential elements of the electro-optical imaging system EOIS for space applications and how these elements can affect its function. After designing a spacecraft for low orbiting missions during day time, the design of an electro-imaging system becomes an important part in the satellite because the satellite will be able to take images of the regions of interest. An example of an electro-optical satellite imaging system will be presented through this paper where some restrictions have to be considered during the design process. Based on the optics principals and ray tracing techniques the dimensions of lenses and CCD (Charge Coupled Device) detector are changed matching the physical satellite requirements. However, many experiments were done in the physics lab to prove that the resizing of the electro optical elements of the imaging system does not affect the imaging mission configuration. The procedures used to measure the field of view and ground resolution will be discussed through this work. Examples of satellite images will be illustrated to show the ground resolution effects.
This document outlines methods for passive stereo vision, from traditional to deep learning-based approaches. It discusses modeling from multiple views, stereo matching techniques like dense correspondence search and cost aggregation. Traditional methods include semi-global matching and energy minimization using graph cuts or belief propagation. Deep learning has also been applied to learn sparse depth representations and end-to-end stereo matching. The document provides an overview of techniques and challenges in passive stereo vision.
- The document describes a method for using image processing software to automate and improve the precision of focusing in femtosecond direct laser writing. Images of laser light reflected off glass samples at different positions relative to the focal plane were analyzed. Signature intensity and area patterns were used to locate the focal plane within 500nm accuracy. Future work includes using this method to assist with additional laser writing processes and surface profiling applications.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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This document summarizes a research paper that presents a real-time 3D reconstruction method using stereo vision from a driving car. The method extends LSD-SLAM with stereo capabilities to simultaneously track camera pose and reconstruct semi-dense depth maps. It is evaluated on the KITTI dataset and compared to laser scans and traditional stereo methods. Results show the direct SLAM technique generates visually pleasing and globally consistent semi-dense reconstructions in real-time on a single CPU.
High quality single shot capture of facial geometryBrohi Aijaz Ali
This document describes a passive stereo vision system that can capture the 3D geometry of a human face in a single shot with high quality. The system uses a calibration method with fiducial markers on a sphere to calibrate multiple cameras. It then performs stereo matching across camera pairs to generate a dense disparity map and 3D mesh for the face. The system introduces an image-based technique to refine the mesh and capture fine geometric details like pores. Evaluation shows the system can accurately capture faces of varying ages, genders and expressions using both a high-end studio setup and a consumer binocular camera.
data acquisition methods in reverse engineeringRanjith Mech
This document discusses various data acquisition methods for 3D scanning, including non-contact methods like triangulation, structured lighting, image analysis, and interferometry, as well as contact methods like robotic arm CMM and acoustic. Triangulation uses light sources and cameras to deduce position, while structured lighting projects patterns onto surfaces which are analyzed to determine coordinates. Image analysis examines stereo image pairs to determine height and position. Interferometry projects fringes and analyzes moire patterns to calculate distances and surface coordinates. Tactile methods use mechanical arms to determine relative positions. CMMs can accurately collect data by following planned paths. Acoustic reflects sound off surfaces, while time of flight measures light pulse travel times to determine distances.
The document discusses the process of creating a digital elevation model (DEM) through photogrammetry, which involves processing overlapping aerial or satellite images into a stereo pair, establishing ground control points, and extracting terrain data to generate an orthorectified DEM and orthophotos through steps like interior and exterior orientation. Key inputs include stereo image pairs, ground control points, and sensor specifications, while the desired outputs are an accurate georeferenced DEM and orthophotos within specified accuracy standards.
Computed Radiography and Computed Tomographykarthi keyan
The document discusses computed radiography (CR) and computed tomography (CT) as non-destructive testing techniques. CR uses imaging plates that store exposure data from x-rays which is then read digitally, allowing sharing of digital images. CT produces cross-sectional images of an object using x-rays and a computer to correlate images taken from different angles as the object is rotated. Both techniques allow internal inspection of parts and detection of defects without damaging the parts.
Automated Motion Detection from space in sea surveillanceLiza Charalambous
This document summarizes research on automated motion detection of vessels from space using satellite imagery. The researchers used ALOS PRISM satellite triplets to detect vessel movement in ports in Cyprus. Through image segmentation, pattern extraction and description, and proximity searching between images, the method detected vessel movement, speed, and direction. It achieved over 90% detection rates but struggled with small vessels. Combining results from multiple image sets improved reliability. The researchers conclude motion detection from satellites can provide critical maritime security information when combined with other data sources.
CT based Image Guided Radiotherapy - Physics & QASambasivaselli R
This document discusses quality assurance for CT-based image guided radiotherapy. It describes existing technologies like kV CBCT, MV CBCT and XVI imaging. It provides details on the XVI system including its x-ray generator, imaging panel, image acquisition and reconstruction process. The document outlines various quality assurance tests for geometric accuracy, image quality and registration including uniformity, spatial resolution and accuracy tests using phantoms.
Similar to Lecture 4 image measumrents & refinement (20)
This document provides an overview of modern survey instruments, including laser levels, digital levels, total stations, GNSS/GPS systems, and laser scanners. It lists the components and purposes of these instruments, such as electronic theodolites, EDM units, data collectors, and prisms for total stations. Ranges for total stations are given as up to 5400m. Leica systems such as the GPS500, GPS900, GPS1200 and GNSS Viva are also mentioned.
This document provides tips for getting help with practical surveying projects. It recommends using Google to search for instrument manuals and forums, and searching inside manuals using control-F. Key tips include leaving most of the searching to Google, knowing tricks for effective searches, and searching brands, models, and keywords to find the most relevant PDF manuals. It also recommends registering for surveying forums to ask questions and get extra help from other users.
This document discusses stereoscopic parallax and its use in photogrammetry. Stereoscopic parallax is the apparent shift in position of an object's image between two overlapping photographs taken from different positions. The amount of parallax is directly related to the object's elevation - higher objects have greater parallax. Parallax can be measured directly on the photographs or using a stereoscope. The parallax measurements can then be used in trigonometric equations to calculate the ground coordinates and elevations of points visible in the stereo pair. These parallax methods provide a fundamental way to determine elevations from aerial photographs.
This document provides an overview of vertical photographs in photogrammetry. It discusses key assumptions and definitions for vertical photographs, including that the optical axis is exactly vertical [1]. Near-vertical photographs can have small intentional tilts of 1-3 degrees [2]. Geometry, scale, relief displacement, and methods for determining flying height from vertical photographs are described through examples [3].
This document discusses the fundamentals of photography and optics. It explains that photography involves capturing light to draw images, with early forms dating back to ancient times. Modern photography is based on the same optical principles but uses digital cameras. The document then discusses key optics concepts like light waves, frequency, amplitude and wavelength. It covers the basics of lenses, how they gather and focus light rays, and defines terms like the optical axis and focal length. Sample lens calculations involving angles of incidence and refraction are also presented.
Errors and Uncertainty are parts of surveying. These slides start first by defining scale and measurements, then show how to determine the uncertainty in measurements. For making these slides I used some books as well; Surveying_Engineering Surveying 6th edition, Surveying Problem Solving, & Surevying_Elemntary Surveying an introduction to Geomatics_Paul R. Wolf.
This is an overview of my current metallic design and engineering knowledge base built up over my professional career and two MSc degrees : - MSc in Advanced Manufacturing Technology University of Portsmouth graduated 1st May 1998, and MSc in Aircraft Engineering Cranfield University graduated 8th June 2007.
Sri Guru Hargobind Ji - Bandi Chor Guru.pdfBalvir Singh
Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
afterwards, Guru Arjan was arrested, tortured and killed by order of the Mogul Emperor
Jahangir.
• Guru Hargobind's succession ceremony took place on 24 June 1606. He was barely
eleven years old when he became 6th Guru.
• As ordered by Guru Arjan Dev Ji, he put on two swords, one indicated his spiritual
authority (PIRI) and the other, his temporal authority (MIRI). He thus for the first time
initiated military tradition in the Sikh faith to resist religious persecution, protect
people’s freedom and independence to practice religion by choice. He transformed
Sikhs to be Saints and Soldier.
• He had a long tenure as Guru, lasting 37 years, 9 months and 3 days
Cricket management system ptoject report.pdfKamal Acharya
The aim of this project is to provide the complete information of the National and
International statistics. The information is available country wise and player wise. By
entering the data of eachmatch, we can get all type of reports instantly, which will be
useful to call back history of each player. Also the team performance in each match can
be obtained. We can get a report on number of matches, wins and lost.
Better Builder Magazine brings together premium product manufactures and leading builders to create better differentiated homes and buildings that use less energy, save water and reduce our impact on the environment. The magazine is published four times a year.
Covid Management System Project Report.pdfKamal Acharya
CoVID-19 sprang up in Wuhan China in November 2019 and was declared a pandemic by the in January 2020 World Health Organization (WHO). Like the Spanish flu of 1918 that claimed millions of lives, the COVID-19 has caused the demise of thousands with China, Italy, Spain, USA and India having the highest statistics on infection and mortality rates. Regardless of existing sophisticated technologies and medical science, the spread has continued to surge high. With this COVID-19 Management System, organizations can respond virtually to the COVID-19 pandemic and protect, educate and care for citizens in the community in a quick and effective manner. This comprehensive solution not only helps in containing the virus but also proactively empowers both citizens and care providers to minimize the spread of the virus through targeted strategies and education.
Sachpazis_Consolidation Settlement Calculation Program-The Python Code and th...Dr.Costas Sachpazis
Consolidation Settlement Calculation Program-The Python Code
By Professor Dr. Costas Sachpazis, Civil Engineer & Geologist
This program calculates the consolidation settlement for a foundation based on soil layer properties and foundation data. It allows users to input multiple soil layers and foundation characteristics to determine the total settlement.
Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
This is an overview of my career in Aircraft Design and Structures, which I am still trying to post on LinkedIn. Includes my BAE Systems Structural Test roles/ my BAE Systems key design roles and my current work on academic projects.
2. Introduction
◼ Measurements may be the lengths of lines between imaged points.
◼ Coordinates of imaged points are the most common type of photographic
measurement.
◼ Image coordinates directly used in many photogrammetric Eq.
◼ Coord. Usually made on positives printed on paper, film, or glass, or in
digital images on PC.
◼ Equipment varies from expensive to low cost such as complex machines
that provide computer-compatible digital output to simple scales.
◼ Systematic errors associated with practically all photographic
measurements.
◼ These errors and the manners by which they are eliminated are to be
discussed in this lecture.
3. Coordinate system for image
measurement
◼ Metric camera with F. M., rectangular axis system by joining F. M is
commonly adopted.
◼ The x axis parallel and positive in the direction of flight.
◼ The positive y axis is 90° - from positive x.
◼ The origin of the coordinate system is the intersection of F.M lines.
◼ Position of any image point is given by
its rectangular coordinates xa and ya.
◼ xa is perpendicular distance from y axis
to a.
◼ ya is perpendicular distance from x axis
to a.
◼ Distance ab can be calculated
4. Photographic Measurements from
simple scales
◼ Engineering scale can be used when lower order accuracy is required.
◼ available in both metric and English units and have several different
graduation intervals.
◼ Precision and accuracy can be enhanced by magnifier glass for fine
reading.
◼ For better accuracy, glass scale may be
used.
5. Measuring photo Cordinates
◼ The photo coordinate axis system will be marked first using eng. Scale via
the FM with lines extended using usual 4H pencil.
◼ Perpendicular distances from a points to the formed axis are used to obtain
rectangular coordinates.
◼ The measured coordinates of a point preferred to be sharp and distinctive.
◼ If not, further identification is required with a small pinprick carefully
under magnification.
6. Comparator measurement
◼ Used for film photograph with final coordinate
measurement accuracy.
◼ Comparator able to extract precise photo
coordinates necessary for calibration &
analytical photogrammetry (2 -3) μm.
◼ Are classified nto two basic types
(monocomparators & stereocomparators).
◼ Monocomparators make measurements on one
photograph at a time.
◼ With stereocomparators image positions are
measured by simultaneously viewing an
overlapping stereo pair of photographs
Kern Monocomparator
No longer in use
Stereocomparator by Carl Zeiss, c.
1920
7. Photogrammetric Scanners
◼ Device used to convert analogue to digital.
◼ It is essential that a photogrammetric scanner have sufficient geometric
and radiometric resolution as well as high geometric accuracy.
◼ photogrammetric scanners should be capable of producing digital images
with minimum pixel sizes on the order of 5 to 15 μm.
Leica DSW700 Digital Scanning
8. Refinement of Measured Image
Coordinates
Correction needs to be applied to eliminate or mitigate the systematic
errors from various sources
1. Distortion in focal plane
◼ Film distortions due to shrinkage, expansion, and lack of flatness;
◼ CCD array distortions due to electrical signal timing issues or lack of flatness of the
chip surface
2. Principal point location
◼ Failure of photo coordinate axes to intersect at the principal point;
◼ Failure of principal point to be aligned with centre of CCD array
3. Lens distortions
4. Atmospheric refraction distortions
5. Earth curvature distortion
9. Image Plane Distortion
◼ Shrinkage or expansion present in photograph can be calculated by
comparing the measured distances from fiducial with calibrated FM.
◼ Photo coordinates can be corrected if discrepancies exist.
◼ Depending on necessary level of accuracy, if lower accuracy required
with eng. scale, the following approach is followed:
Where:
xm & ym : measured fiducial distances positive
xc & yc : calibrated fiducial distances positive
x’
a & y’
a : corrected photo coordinates
xa & ya : measured photo coordinates
10. example
For high-accuracy applications, shrinkage or expansion corrections may
be applied through the x and y scale factors of a two-dimensional affine
coordinate transformation.
11. Correction for Lens Distortions
◼ Comprised of two components: symmetric radial distortion & decentring
distortion.
◼ Lens distortions are typically less than 5 μm for modern precision aerial
mapping cameras.
◼ Symmetric radial lens distortion is an unavoidable product of lens
manufacture.
◼ Imperfect assembly of lens elements cause decentring distortion.
◼ Radial lens distortion calculated using the polynomial form
Δr = k1r1+ k2r3+ k3r5+ k4r7
Where Δr = amount of radial lens distortion
r= is the radial distance from the principal point.
k1, k2, k3, k4 = coefficients of the polynomial
18. Correction for Lens Distortions
◼ In modern mapping camera, the lens design evolved to such a level that
symmetric radial and decentring are is of the same order of magnitude.
◼ Simultaneous Multi-camera Analytical Calibration (SMAC) model as an
example is used with USGS calibration procedure.
◼ SMAC computes both distortion parameters in addition to PP & f directly
by LS.
◼ Solved parameters are (k0, k1, k2, k3, k4), (p1, p2, p3, p4), (xp, yp), & f.
Δx, Δy = decentring distortion correc.
r = is the radial distance from the PP.
k0, k1, k2, k3, k4 = coefficients of the
symmetric radial lens distortion
= coordinates of the image
relative to the PP.
p1, p2, p3, p4 = are coefficients of
decentring distortion.
= sym. rad. lens disto. correct.
21. Correction for Atmospheric Refraction
◼ Density or RI of the atmosphere decreases with increasing altitude.
◼ Therefore, light rays do not travel in straight line but bent according to
Snell's law, figure.
◼◼ object point A would be imaged a’.
◼ Angular distor. due refr. is Δɑ.
◼ Refr. cause all im. pts to be diplaced
outward from corc.pos.
◼ Magn. of ref, disto. Increases with
increases of flying height.
◼ Refraction distr. occurs radially from
the photo NP & zero at the NP.
◼ For further read see section 4-12 of the
Element of Photogrammetry by wolf.
◼ Equations do not included for this Lect.
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