64
Oxford Technical Solutions
If the antennas are mounted at significantly different heights, or if the mounting angle is
not directly along a vehicle axis (forward or right), then click the Use advanced settings
checkbox to enable advanced settings and specify the orientation and height offset.
Getting the angle wrong by more than 3° can lead the RT to lock on to the wrong heading
solution. The performance will degrade or be erratic if this happens. If the angle between
the antennas cannot be estimated within a 3° tolerance then contact OxTS support for
techniques for identifying the angle of the antennas.
The Enable static initialisation option is useful for slow moving vehicles or where it is
essential to start the RT running before moving (for example in autonomous vehicles).
Static initialisation is 99% reliable in open sky, but the reliability decreases in
environments with high multipath. Static initialisation is also faster when the antenna
separation is smaller.
If you can guarantee the antennas are level (always within 15° of horizontal) during static
initialisation then the following advanced command can also speed up static initialisation
and make it more reliable:
-gps_pitch15.0
This is a “pitch constraint” (or “tilt constraint”). Enter this text into the Advanced
window on the Options page. It will tell the ambiguity resolution algorithm to only search
within 15° of the horizontal. Note that this is the angle between the antennas and it is
independent of the height offset entered in to the software.
The RT will improve the estimate of the secondary antenna orientation settings. Use the
Get improved settings utility to use the improved values. More information on Get
improved settings is provided on page 59.
Advanced slip
The Advanced slip feature uses characteristics of land vehicle motion to improve heading
and slip angle and to reduce drift. Specifying the position of the non-steered wheels
makes a huge difference to the lateral drift performance of the RT when GNSS is not
available.
This feature must be disabled for airborne and marine systems where the lateral velocity
can be significant. This feature is also not suitable for land vehicles that use all wheels
to steer, i.e. no fixed wheels. The vertical settings should not be used if the vehicle can
perform wheelies.
The Advanced slip feature applies heading correction when the land vehicle is not
slipping. When the vehicle is slipping the lateral acceleration is usually large enough that
the normal heading corrections provide excellent results. When combined with a wheel
To Next Page
Loading...
Need help?
General
