Technical data

Tables
CMD The Alvarion GPS unit’s Command Port.
CMOS A type of semiconductor fabrication process (Complementary
Metal Oxide Semiconductor), resulting in low power. CMOS
devices require static protection during handling.
CNO Carrier to Noise ratio (dBHz), a measure of signal quality.
COM Port Communication port, e.g. PC serial communication ports
COM1 etc.
CONUS Continental United States
CPU Central Processing Unit (usually the microprocessor)
CTS Clear to Send (serial communication handshaking)
Datum The reference shape of the Earth’s surface used in the
construction of a map or chart. Usually chosen for a ‘best fit’
over the area of interest and thus the Datum for various parts
of the world may differ. Alvarion GPS supports WGS84.
Delta Range Small changes in range between a satellite and the receiving
antenna.
DoD American Department of Defence.
DOS Disk Operating System.
DOP A DOP (Dilution of Position) is a figure which represents the
purely geometrical contribution of the satellites’ positions to
the total position error budget. Low values of a DOP (1 - 5)
mean that the calculated position should be good whilst
higher DOP values indicate a greater uncertainty in the
determined position. Good DOP values are obtained when
satellites are well spaced geometrically, whilst poor values
result from available satellites all being visible in similar
directions. When the DOP value is excessive (e.g. > 100) then
neither standalone nor differential positions should be used.
DR Dead Reckoning - a means of estimating present position
based on a known starting position updated by applying
distance and direction of the user’s movements.
GPS Timing Receiver Installation and Operation Manual
E-2