Trimble Outdoors SPSX51 - Manual (Page 102)

8 Automatically Setting up a Mobile Base Station Using AutoBase Technology
100 SPSx51 Modular GPS Receivers User Guide
AutoBase Warning
The AutoBase Warning, when enabled, prevents the receiver from creating a new base
station position and begin operating as an RTK base station when no previous base
station position exists that corresponds to the current position of the receiver.
When the AutoBase Warning is on, the receiver will not begin transmitting RTK
corrections from a base position (latitude, longitude, and height) that is not a part of
the GPS site calibration. When the AutoBase Warning is off, the receiver begins
transmitting RTK corrections from a new base position. You need only turn on the
receiver the first time on a point, and you do not need to manually configure the base
station settings.
By default, the receivers have the AutoBase Warning turned on. The receiver uses the
AutoBase Warning setting to control how the receiver performs when different criteria
are met. You can turn the AutoBase Warning on or off using the keypad and display. For
more information, see
Configuring system settings, page 68 .
Working with AutoBase technology
This section contains some example scenarios. In each section, there is a step-by-step
process that explains what you will experience in each scenerio.
Scenario One: First visit to a site with AutoBase Warning turned off
The following actions occur when you set up the base station for the first time on a
new point and the AutoBase Warning is turned off:
1. The receiver is powered on.
2. The receiver begins tracking satellites.
3. The receiver determines the current position.
4. The receiver reviews the previous base station positions stored in the receiver.
5. The receiver does not find any base station that corresponds to the current
position.
6. The receiver creates a new base station location for the current location.
7. The receiver sets the antenna height to 0. The antenna height is measured to the
bottom of the antenna mounting.
C
CAUTION – On each reoccupation of the point, you must ensure that the receiver
antenna is set up in exactly the same location and at exactly the same height. Trimble also
recommends that you use a T-bar or Fixed height tripod so that the position is easy to
re-establish. Failure to achieve the same height position for the antenna results in errors
in heights in subsequent measurements.