The following information describes the various options available for Thales/Ashtech GPS.

SurvCE works with the following high precision, centimeter accurate RTK GPS equipment produced by Thales/Ashtech: Z12/Sensor, ZSurveyor, GG24, Z-Xtreme and Z-Max. SurvCE also works with the Ashtech Reliance USCG/DGPS RTCM sub-meter RTK GPS receivers.

Shown below is the front panel view of the Ashtech Z-Xtreme, as it appears in the top of the backpack. 

Shown in the next photo is the cabling for the Z-Xtreme, looking at the back panel.

Configure Base (Station)

• Receiver Type: You must specify the model of Thales/Ashtech equipment to be used.
• Base Antenna Height: This is entered as a "vertical" or "slant" height in the current job units.  The slant height is the distance from the base of the pole or from the “hub and tack” up to a mark or defined slant measurment point on the edge of the antenna (See NGS for more details). The vertical height is measured plumb, straight down from the base of the antenna (where it screws into the antenna).
• Antenna Type: A pulldown list that includes approximately 50 different antenna types. Shown in the below photo is the Geodetic 4 antenna.

• Elevation Mask: This specifies the cutoff vertical angle above the horizon.  Any satellites below this angle will be left out of calculations.
• Log Thales OBEN: This setting specifies that the software will log the standard Thales OBEN file as specified by Thales.
• Log User OBEN: This setting specifies that the software will record the OBEN with the recording interval set per the user.

Configure Base (Ports)

• Data Port: You must select the data port on the GPS receiver that is connected to SurvCE. The default setting is B. Changing this setting will change the internal setting of the receiver.
• Radio Port: You must select the data port on the GPS receiver that is connected to the radio modem. The default setting is A. Changing this setting will change the internal setting of the receiver.
• Radio Type: This allows the user to specify the various supported radios.
• Message Type: You must specify the message type. For high precision centimeter RTK GPS, set this to Ashtech (CPD). For USCG/RTCM DGPS sub-meter accuracy, set this to RTCM.
• Radio Baud Rate: This setting allows you to change Pacific Crest radio baud settings through the receiver.  The default baud rate is 9600.  (Note: If there are communication problems with either port A or B on the Ashtech ZSurveyor receiver, turn off receiver and turn it back on with both keys depressed to reset receiver to factory defaults.)

Configure Rover (Parameters)

• Multipath Type: You must specify this setting in order to filter out interference in the satellite signals caused by nearby objects.
• Dynamics: This setting is applied to all Thales equipment types with the exception of the Z-Max.  Here you may specify the dynamics setting. Static is selected only when the Rover receiver is stationary. The default is Walking. When set to Static, the HRMS and VRMS values (measurements of accuracy) will fall to very low numbers (high accuracy), but lock will not hold unless the antenna is motionless.  Static is recommended when the antenna and pole are secured by a tripod or bipod.
• Ambiguity Fixing Parameter: This controls the confidence level of fixed positions. The default is 99.0. At a lower confidence interval the system solves much faster. If the system incorrectly solves the position, then the position error will be much greater than the reported RMS value.
• Fast CPD: This option specifies whether or not the program will allow approximating the rover’s position if your position is lost briefly.  Off is the default. Fast CPD is generally toggled on when Dynamics is set to Automobile.
• Rover Antenna Height: This is entered as a "vertical" or "slant" height in the current job units.  The slant height is the distance from the base of the pole or from the “hub and tack” up to a mark or defined slant measurment point on the edge of the antenna (See NGS for more details). The vertical height is measured plumb, straight down from the base of the antenna (where it screws into the antenna).

Configure Rover (Receiver)

• Receiver Type: You must specify the model of Thales/Ashtech equipment to be used.
• Antenna Type: A pulldown list that includes approximately 50 different antenna types.
• Turn Beep Off: This disables the beeping noise the receiver makes for message alerts.
• Elevation Mask: This specifies the cutoff vertical angle above the horizon.  Any satellites below this angle will be left out of calculations.
• Log Thales OBEN: This setting specifies that the software will log the standard Thales OBEN file as specified by Thales.
• Log User OBEN: This setting specifies that the software will record the OBEN with the recording interval set per the user.
• Log OBEN Data for Averaged RTK Readings: This setting enables the OBEN file to record all averaged RTK readings.

Configure Rover (Ports)

• Data Port: You must select the data port on the GPS receiver that is connected to SurvCE. The default setting is B. Changing this setting will change the internal setting of the receiver.
• Radio Port: You must select the data port on the GPS receiver that is connected to the radio modem. The default setting is A. Changing this setting will change the internal setting of the receiver.
• Radio Type: This allows the user to specify the various supported radios.
• Message Type: You must specify the message type. For high precision centimeter RTK GPS, set this to Ashtech (CPD). For USCG/RTCM DGPS sub-meter accuracy, set this to RTCM.
• Radio Baud Rate: This setting allows you to change Pacific Crest radio baud settings through the receiver.  The default baud rate is 9600.  (Note: If there are communication problems with either port A or B on the Ashtech ZSurveyor receiver, turn off receiver and turn it back on with both keys depressed to reset receiver to factory defaults.)
• VRS: Use this setting if working in a VRS network.