Spectra Precision Survey Pro v3.80 Recon GPS User Manual - Manual (Page 20)

GPS User’s Manual
16
Survey Pro Coordinate System
Database
Survey Pro uses a Coordinate System Database file (*.CSD) to store
the map projection and datum transformation parameters for many
different coordinate systems around the world. Also, horizontal and
vertical localization adjustments are stored as site records in the
database. Below is a list of the terminology used to describe the
different records in the coordinate system database.
•
Zone: Is the basic record type. A zone record specifies the type of
map projection and its parameters. Most zone records have
datum and ellipsoid records, and usually a geoid record, already
in the database.
•
Site: Is a zone record with a horizontal and/or vertical
localization adjustment added. Localizations are usually used to
correct GPS positions starting from an autonomous base. They
can be computed from control points or from manual input of
parameters.
•
Zone Group: Is a collection of zone and/or site records used to
keep the database organized and user selection easier.
•
Datum: Is a type of datum transformation and its parameters. A
datum record will always have an ellipsoid record already in the
database.
•
Ellipsoid: Are the two parameters specifying the ellipsoid of the
datum.
•
Geoid: Is a geoid model and its associated data file.