ashtech DG16 Reference Manual page 361

Aerotriangulation
(phototriangulation)
A complex process vital to aerial
Photogrammetry that involves
extending vertical and/or horizontal
control so that the measurements of
angles and/or distances on
overlapping photographs are related to
a spatial solution using the perspective
principles of the photographs.
Aerotriangulation consists of
mathematically extending the vectors/
angles of the triangular pattern of
known reference points on or near the
designated photo-block terrain upward
through a rectangle representing the
area of the photo-block (as seen by the
camera's optical center) in such a way
that the tree-point terrain triangle and
the camera's eye three-point triangle
(within the photographic frame) are
analogous.
AFT
After
AGE
Age of Data
ALM
See Almanac
Almanac
A set of parameters used by a GPS
receiver to predict the approximate
locations of all GPS satellites and the
expected satellite clock offsets. Each
GPS satellite contains and transmits the
almanac data for all GPS satellites (See
Ellipsoid).
ALT
Altitude
Ambiguity
The initial bias in a carrier-phase
observation of an arbitrary number of
carrier cycles; the uncertainty of the
number of carrier cycles a receiver is
attempting to count. If wavelength is
known, the distance to a satellite can be
computed once the number of cycles is
established via carrier-phase processing.
AMI
ATM Management Interface
ANT
Antenna
341