APPENDIX A
GLOSSARY
Almanac data - A data file which indicates the orbital paths and status of all
known satellites. Almanac data is transmitted by all operational GPS
satellites and is stored in your GPS receiver.
ASCII file - A text file that follows the American Standard Code for Informa-
tion Interchange. These files may be readily viewed/edited using a word
processor program or a DOS text editor.
DXF format - Drawing Interchange Format. An ASCII file format used by
various graphic and CAD programs (e.g. AutoSketch
®
). Each ASCII line in
a DXF file describes an object within the overall drawing.
EMS - Expanded Memory System. Memory added to your computer above,
and beyond, conventional memory (usually on an expanded memory board).
The expanded memory board, and supporting expanded memory manager,
should conform to the LIM (Lotus/Intel/Microsoft) version 3.2 specification.
HDOP - Horizontal Dilution of Precision. HDOP is an indicator of the quality
of a horizontal position (latitude and longitude) based on satellite geometry
(or, position of the satellites with respect to each other). A low HDOP value
indicates better position accuracy.
PDOP - Position Dilution of Precision. PDOP is an indicator of the quality of
a horizontal and vertical position (latitude, longitude and altitude) based on
satellite geometry. A low PDOP value indicates better position accuracy.
Track log - This file contains a list of position data samples (each sample
having a unique time assigned to it) which indicates where you have been.
Track log files are created/stored in your GPS unit and downloaded to the PC.
UTM/UPS - Universal Transverse Mercator / Universal Polar Stereographic.
UTM/UPS is a popular coordinate system used in survey and mapping
applications. UTM/UPS relies on grid zone designations, easting/northing
distances and provides one meter resolution.
YUMA format - An ASCII file format used to define the orbital parameters for
each operational GPS satellite. YUMA format is used by a variety of satellite
tracking programs.
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