Gps Antenna; Satellite Elevation Mask - Racelogic VBOX3i User Manual

VB3i MANUAL

GPS antenna

The GPS antenna supplied with the VBOX3i is a 5V active antenna. For the best possible signal quality, it is important
to maintain a clean connection between the antenna and the VBOX3i. Before fixing the antenna to the VBOX3i, ensure
that there are no dust particles in either connector. Replacement antennae are available by contacting your VBOX3i
distributor.
The antenna is a magnetic mounting type for quick and simple mounting to the vehicle roof. For optimum GPS signal
reception, make sure that the antenna is fitted to the highest point of the vehicle away from any obstructions that
may block satellite reception. The GPS antenna works best with a metal ground plane underneath (a metallic vehicle
roof is perfect for this).
Please also note that when using any GPS equipment, a clear sky view is important. Objects in the surrounding area
such as tall buildings or trees can block the GPS signal causing a reduction in the number of satellites being tracked, or
introducing reflected signals that can decrease the accuracy of the system. Note that clouds and other atmospheric
conditions do not affect the VBOX3i's performance.
GPS antennas require a ground plane to operate correctly. This
helps to reduce unwanted reflections of the GPS signal caused by
nearby objects, and usually the metal roof of a vehicle performs
this function. However, if a test requires an antenna to be placed
either off the vehicle, or on a vehicle that does not have a metallic
roof, a special ground plane antenna must be used. This has an
internal ground plane and can operate perfectly without the need
for mounting on a metal surface. Ground plane antennas are
available from your VBOX3i distributor.

Satellite elevation mask

This feature can be used to improve GPS signal quality when nearby obstacles like trees and building are reflecting or
temporarily obscuring the signal from satellites at low elevation. Raising the mask will cause the GPS engine to ignore
satellites below the mask angle, so must be used carefully as it also reduces the total number of received satellites.
The elevation mask angle can be changed in the GPS section within VBOX Tools Setup.
VBOX Tools
Version 2.2.2b42 and above now has an option to change the SEM value for the VBOX3i series.
Page | 11 22 May 2014