Glossary

GPS

Global Positioning System. A satellite-based navigation

 

system operated and maintained by the U.S. Department of

 

Defense and consisting of a constellation of 24 satellites

 

providing worldwide, 24-hour, three-dimensional (3-D)

 

GPS coverage. These satellites transmit signals used (by

 

GPS receivers) to determine precise location (position,

 

velocity, and time) solutions. GPS signals are available in all

 

weather conditions. This system also includes 5 monitor

 

ground stations, 1 master control ground station, and 3

 

upload ground stations.

 

GPS is emerging as the technology of choice in many timing

 

applications, including site and network synchronization.

GPS antenna

An antenna designed to receive GPS radio navigation

 

signals.

GPS processor

An electronic device that interprets the GPS radio

 

navigation signals (received by a GPS antenna) and

 

determines a location solution. The GPS processor may also

 

be able to apply (and determine) differential GPS

 

corrections.

GPS receiver

The combination of a GPS antenna and a GPS processor.

GPS time

The length of the second is fixed and is determined by

 

primary atomic frequency standards. Leap-seconds are not

 

used, as they are in UTC. Therefore, GPS time and UTC

 

differ by a variable whole number of seconds.

HDOP

Horizontal Dilution of Precision.

host system

The device or instrument connected to the Acutime 2000

 

smart antenna. The host system can be a PC, network

 

equipment, or timing system, depending on the application.

HOW

Hand-over word. The word in the GPS message that

 

contains time synchronization information for the transfer

 

from C/A to P-code.

Acutime 2000 Synchronization Kit User Guide

Glossary-7

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Trimble Outdoors AcutimeTM2000 Synchronization Kit, Part Number 45005-00-ENG manual Gps