Photogrammetry definitions of commonly used terms, Part 3

Here you find some useful Photogrammetry definitions of commonly used terms.This post is continuation of Photogrammetry definitions of aerial photogrammetry terms.
photogrammetrydevelopment

Photo ID
Ground control points collected at well defined, visible, recoverable locations.

Photo enlargement
Large paper or mylar photographic reproduction of a aerial negatives.



Pixel
Term used for the Row / Column units that make up a raster file or digital image.

PUG point
Small point drilled into the surface of a diapositive used as a derived control point in the aerotriangulation process.

Raster
Computer files made up of rows and columns of values. These values are usually greyscale or colors stored in such a way that when they are read by a viewing program they form a digital photograph.

Relief displacement
The distortion caused in an aerial photograph caused by objects being displaced away from the center as their elevation changes.

Signal
Pre fabricated or "made in place" markers for control points. Usually a cross or "T" centered over a pin or hub to make the location visible from the air.

Softcopy
A term given to photogrammetric instruments in which the electronics, lenses, and motors of the analytical instrument have been replaced by a 3-Dimensional view of the ground displayed and measured on a computer screen.

Stereomodel
Two overlapping aerial photographs viewed in 3-D. The basis for all measurements made by photogrammetric methods

TIFF
Popular format of raster file when used for aerial photos it is delivered uncompressed and georeferenced with a world file. Because it is uncompressed it is as perfect a copy of the original photo as is possible.

TIN
Triangular Irregular Network, one of many names used to describe a file describing terrain shape. Usually used to describe the data as processed for computations by an engineering or analysis software.

Vector
Computer files made up of lines and points which are digitized in a known coordinate system. Entities usually have multiple attributes

World file
A very small standardized support file that some softwares use to geo-reference a digital photograph to a coordinate system.