Specifications

Understanding RTK/CPD 53
Understanding
Other solution messages are also available for query, and not to output periodically
like CBN messages. These messages are UBN and OBN. The UBN message gives
CPD position, velocity, and statistical information in binary format. The OBN
message gives CPD vector and site information in binary format.
Vector Solution Output
This capability allows you to log vector solutions containing the same information as
post-processed vector output files (O-file), allowing the position solutions to be
imported into an adjustment program. Your RTK solutions may then be included as
part of a least-squares network adjustment.
To use this option, a valid site name must be entered (check by using the
$PASHQ,RAW command), and the rover’s GPS antenna must remain stationary until
the site name has been changed to “????.” If the GPS antenna is moving with a site
name entered, the vector solution will not be valid. If no site name is entered, the
vector solution will not be created. Note that a site name must be entered at the base
station as well.
Other Ashtech Real-time Z products, such as GPSTopo, with software running on a
handheld datalogger automate this process, but it may be performed in the receiver
system using the following procedure:
1. Check the solution, as described in “Monitoring the CPD Rover Solution” on
page 51, to ensure that the current accuracy meets your requirements.
2. Place the antenna over the point to be measured.
3. Issue the following serial commands to the receiver using Ashtech’s
REMOTE.EXE program or a similar serial communication:
$PASHS,CPD,DYN,0
$PASHS,CPD,FST,OFF
$PASHS,SIT,xxxx (where xxxx is the site name you wish to use other
than ????)
These three commands set rover motion dynamics to static, turn Fast CPD
off, and set a site name.
4. To improve the vector solution, you may wait for 5-10 epochs of data before
issuing the next set of commands:
$PASHS,CPD,DYN,2
$PASHS,CPD,FST,ON
$PASHS,SIT,????
These three commands reset the unit for dynamic operation.