Novatel SUPERSTAR II OM-20000077 - Manual (Page 31)

Operation Chapter 4
SUPERSTAR II User Manual Rev 3 31
4.3 Data Requests
Data may be requested for output by the receiver for display or logging purposes. The list of data request
commands and data messages is detailed in the L1 GPS Firmware Reference Manual.
4.4 Configurable Parameters
Several parameters of the receiver and the base station are configurable and therefore, you must define them
prior to operation.
Your receiver must be a BASE model to act as a base station. A list of models is in Appendix A of the L1
GPS Firmware Reference Manual and in our Price List available from the Sales side menu of our website
at
www.novatel.com .
4.4.1 Mask Angle
The mask angle is defined as the minimum satellite elevation angle (in degrees) above which any given satellite
must be in order for it to be used in the GPS position solution. Low satellites usually do not yield accurate
measurements due to weak signal reception and possible multipath. Typical mask angle values range from 5
°-
10
°, depending on the receiver’s location. This value is programmable using command Message ID# 81, Set
Mask Angle.
4.4.2 GPS Antenna Position
For the base station, it is imperative to fix the position. This can be done using either the X-Y-Z coordinates in
meters within the WGS-84 reference frame, or latitude and longitude in degrees and height in meters (LLH
coordinates) by selecting Tool Setting | Set Operating Mode in the main menu of StarView.
You can also set the X-Y-Z coordinates using Message ID# 80, Set User’s Position/Operating Mode.
4.5 Receiver States
4.5.1 Non-Operational State
The receiver’s non-operational state is OFF mode. In OFF mode, only the data contained in the NVM is
retained for use when power is re-applied. See Section 3.5, Protocol Selection and Non Volatile Memory
starting on Page 24 for details on retained data. A supercap allows the SUPERSTAR II to maintain data and
time during OFF mode for a period of 3 days to a week.
4.5.2 Operational States
The receiver has 6 operating modes:
• Self-Test
• Initialization
• Acquisition
• Navigation
• Dead-Reckoning
• Fault