Photogrammetry (GEn 322)

Photogrammetry

May be defined as the science, art and technology of obtaining reliable information from photographs.

Metrical and interpretative

Two major areas of specialization of photogrammetry

Metric photogrammetry

Consists of making precise measurements from photos and other information sources to determine, in general, the relative locations of points.

mathematical model and mathematical shape

Metric photogrammetry is concerned with the _________ and ________ of objects

Distances, angles, volumes, elevations, sizes and shapes

Metric photogrammetry enables the finding of D,A,V,E,S & S of objects.

Interpretative photogrammetry

Deals principally in recognizing and identifying objects and judging their significance through careful and systematic analysis

Remote Sensing, Satellite Imagery for Land Use and Land Cover, Normalized Difference Vegetation Index (NDVI)

Sample uses of interpretative photogrammetry

Aristotle (350 B.C)

He had referred to the process of projecting images optically.

Dr. Brook Taylor (18th Century)

He published his treatise on linear perspective.

vanishing point

Parallel lines appear to intersect based on perspective at a converging point called the __________

Vanishing lines

The parallel lines that converge at the vanishing point are called __________

J. H. Lambert

He suggested that the principles of perspective could be used in preparing maps.

Lambert Conformal Conic

Map projection based on Lambert

meridians converge at poles and parallels are a circular arc

In Lambert conformal conic, _________ converge at _______ and ________ are a _________

midlatitude area of greater east-west than north-south extent

Lambert Conformal Conic is the standard choice for mapping a midlatitude area of greater ___________ than __________ extent

secant conic projection

Lambert conformal conic is a conic projection, but specifically it is a __________

Distance, angle and shape

Lambert conformal conic is a conformal projection, which means it RETAINS what properties? (DAS)

Scale, area and distance

Lambert conformal conic is a conformal projection, which means it RETAINS what properties? (SAD)

First and second standard parallels, Central Meridians, Latitude of projection’s origin; False easting and false northing

Parameters of Lambert Conformal Conic: FLCF | F&SSP, CM, LOPO, FE&FN

False easting and false northing

Are adjustments used to avoid negative numbers in the coordinate system, making it easier to work with and ensuring that all locations are represented with positive values.

Joseph Niepce

He produced the world’s first photograph in 1827

heliography

The process used by Joseph Niecpe which used metal plates coated with a tarlike substance that would gradually harden with exposure to light.

Louis Daguerre

He announced his direct photographic process, which was more practical than heliography.

Niepce coated the metal plates with tarlike substance

Daguerre light-sensitized the metal plates using a coating of silver iodide

Differentiate the photography processes of Joseph Niepce

Louis Daguerre

Between Niepce and Daguerre, which photographic process do we still use today?

Francois Arago

He demonstrated the use of photographs in topographic surveying.

Colonel Aimé Laussedat

He experiments kites and balloons were used for taking aerial photographs.

terrestrial photographs

Laussedat faced difficulties in obtaining aerial photographs and such, curtailed this area of research and concentrated his efforts on mapping with _______________

1859

In ______, Colonel Laussedat presented an account of his successes in mapping using photographs.

Father of Photogrammetry

Colonel Aimé Laussedat is dubbed as the _______________

Captain Eduard Deville

He found Laussedat’s principles extremely convenient for mapping the rugged mountains of western Canada.

U.S. Coast and Geodetic Survey

In 1894, ____________ adopted photogrammetry

National Geodetic Survey

U.S. Coast and Geodetic Survey is now called ____________

Canada and the Alaska Territory

The goal of the U.S. Coast and Geodetic Survey in adopting photogrammetry was for mapping along the border between _______________

Dr. Carl Pulfrich(1909)

He began to experiment with overlapping pairs of photographs. His work formed much of the foundation for the development of many instrumental photogrammetric mapping techniques in use today.

Anaglyph(s)

Refers to a type of 3D image or video where two differently colored images (usually red and blue or red and cyan) are combined into one

Wright brothers (1903)

Orville Wright and Wilbur Wright

They invented the airplane provided the great impetus for the emergence of modern aerial photogrammetry.

Terrestrial photographs

A type of photograph taken with ground-based cameras, the position and orientation of which might be measured directly at the time of exposure.

Restoration of archaeological or heritage sites
(As reference for the original formation of the structures)

Cultural/historical application of terrestrial photographs

Crime and accident scenes

Forensic use of terrestrial photographs

Aerial Photographs

These are photographs of the terrain taken by a precision camera mounted in an airplane, balloon or spacecraft flying over the area.

Drone

Aerial craft developed for efficiency in taking aerial photographs

Vertical photos

A type of aerial photograph that are taken with the camera axis directed as nearly vertically as possible

Photographic plane would be parallel to the datum plane

If the camera axis were perfectly vertical when an exposure was made, this means that the __________ would be ________ to the __________.

Truly vertical

_____________ is the term used when the photographic plane is parallel to the datum plane

aircraft tilts

In practice, the camera axis is rarely held perfectly vertical due to unavoidable ________________

tilted photograph

When the camera axis is unintentionally tilted slightly from vertical, the resulting photograph is called a _____________

usually less than 1 degree and seldom more than 3 degrees

The unintentional tilts are usually in the following range: ____________

oblique aerial photographs

A type of aerial photograph exposed with the camera axis intentionally tilted away from the vertical

high oblique photograph

low oblique photograph

In terms of horizon,

__________: has horizon

__________: no horizon

Set 1. Vertical, low oblique, high oblique

Set 2. Vertical, low oblique, high oblique

Identify what type of aerial and explain each.

Image from an analogue camera

Photogrammetric workflows [Identification]: No. 1

Scanning

Photogrammetric workflows [Identification]: No. 2

Scanning involves scanning paper and converting it to digital format

Scanning involves scanning _______ and converting it to _________ format

Measurement of the interior orientation

Photogrammetric workflows [Identification]: No. 3

interior geometry

Interior orientation refers to the ____________ of camera

focal length, focal point and lens orientation

The interior geometry of a camera comprises the ________, _________ and ________

Calibration

Photogrammetric workflows [Identification]: No. 4

Images from a digital camera

Photogrammetric workflows [Identification]: No. 5

Measurement of the exterior orientation

Photogrammetric workflows [Identification]: No. 6

3D Dimension of camera

Exterior orientation is the ___________ of ______ at the time of exposure or position

To project or relay the camera to the ground as the camera and the ground have the same axes for uniformity purposes

Why is exterior orientation needed?

Image co-ordinate measurement (ATM)

Photogrammetric workflows [Identification]: No. 7 & 8

Aerotriangulation / block adjustment

Photogrammetric workflows [Identification]: No. 9 & 10

Aerotriangulation

It’s the process of using photos taken from different angles and figuring out the exact location of each point in those photos

block adjustment

It is a process used in aerial surveying and photogrammetry to correct and refine the positions of multiple photos or images, making sure they all align properly and accurately when creating a map or 3D model.

Model definition

Photogrammetric workflows [Identification]: No. 11

Surface models

Photogrammetric workflows [Identification]: No. 12

Contour lines, 3D views and more

Photogrammetric workflows [Identification]: No. 13 & 14

Vector data

Photogrammetric workflows [Identification]: No. 15

Digitizing

A process that turns image data into vector data

Ortho images

Photogrammetric workflows [Identification]: No. 16

Ortho images

Photos rectified for factors such as but not limited to atmospheric refraction

Mosaics

Photogrammetric workflows [Identification]: No. 17

mosaic

Overlaps are needed to create a ________ such as intersections or building edges or corner monuments like BLLM

Post processing in GIS

Photogrammetric workflows [Identification]: No. 18

topographic maps

Principle application of photogrammetry lies in the production of ___________

line maps and orthophoto maps

Topographic maps created using photogrammetry as in the form of both ________ and _________

3D-digitizers

In photogrammetry, photogrammetric instruments function as ____________

digital topographic model

In a photogrammetric analysis, a ___________ is formed which can be visualized with the aid of computer graphics

Earthworks (cut or fill) and flood risk assessment

Example analysis methods of topographic model

Form and the usage of the surface of the Earth

What are stored in such a digital topographic model?

topographical information system

The digital topographic models are input in a _________________ as the central body of data

natural landscape and the cultural landscape

The inputting of the digital topographic models in a topographical information system provides information about both the _______________ and the ______________ (as fashioned by man)

Geoinformation system (GIS)

A topographic information system is a fundamental subsystem in a comprehensive _______________

geodata

Photogrammetry delivers ____________ to a GIS

Close range photogrammetry

______________ is used for architectural recording; precision measurement of building sites and other engineering subjects; surveillance of buildings and documentation of damage to buildings; measuring up of artistic and engineering models; deformation measurement; survey of moving processes, biometric applications; reconstruction of traffic accidents and very many others

Building site (and other engineering subjects) precision measurement

Biometric applications

Building surveillance and

Damage documentation

Artistic and engineering model measurement

Survey of moving processes

Traffic accident reconstruction

Architectural recording

Close range photogrammetry can be used for: 3BDASTA

Robotics

An example of moving processes

Computer controlled surgical operations

An example of biometric applications

Photography

Which means “drawing with light,” originated long before cameras and lightsensitive photographic films came into use.