Photogrammetry FAQ

Photogrammetry FAQ

What is camera station?
The point in space occupied by the camera lens at the moment of exposure; also called air station or exposure station.

What is calibration?
The act or process of determining certain specific measurements in a camera or other instrument or device by comparison with a standard, for use in correcting or compensating errors of for purposes of record.

What is block adjustment?
The adjustment of strip coordinates or photograph coordinates for two or more contiguous strips of photographs.

What is base height ratio?
The ratio (B:H) of the air base and the flight height of a sterescopic pair of photographs. Also referred to as base altitude ratio, K-factor.

What is attitude?
The angular orientation of a camera, or of the photograph taken with that camera, with respect to some external reference system. Usually expressed as omega (X-tilt), phi (Y-tilt), kappa (Z-tilt); swing and azimuth or roll, pitch and yaw.

What is anti curl backing?
An unsensitized layer of gelation coated to the base side of the film to counter the “pull” of the emulsion side of the film during the drying process.

What is altitude?
Vertical distance above the datum, usually mean sea level, of an object or point in space above the earth’s surface.

What is air base and photo base?
Air Base: The line joining two air stations, or the length of this line; also, the distance between adjacent perspective centres as reconstructed in the plotting instrument.
Photo Base: The length of the air base as represented on a photograph. The distance between the principle points of two adjacent prints of a series of vertical aerial photographs. It is usually measured on one print after transferring the principle point of the other print.

What is aerial film?

Specially designed roll-film supplied in many lengths and widths, with various emulsion types for use in aerial cameras.