Rover options

The fields available in the Rover options screen are similar for all GNSS survey types. All fields that appear in the Rover options screen for any GNSS survey type are described below.

Select the type of survey you want to use. The rest of the fields in the screen update to reflect the survey type selected.

Generally, when a GNSS surveying system setup consists of one base and one rover receiver, make sure that the survey type selected in the Rover options field and the Base options field is the same. However, when there are multiple rovers, you can have various configurations but make sure that if the rover is logging raw data your base station is also logging raw data.

Select the correct antenna from the list of antennas. The Part number field automatically displays the part number.

Select the correct measurement method for the equipment and type of survey. To set the default antenna height, enter a value in the Antenna height field. The Part number field automatically displays the part number.

Enter the serial number.

You must define an elevation mask below which satellites are not considered. For kinematic applications, the default of 10° is ideal for both the base and rover.

For differential surveys where the base and rover are separated by more than 100 kilometers, Trimble recommends that the base elevation mask be lower than the rover setting by 1° per 100 kilometers of separation between the base and rover. Generally, the base elevation mask should be no lower than 10°.

Define a PDOP mask for the rover. When the satellite geometry goes above the set PDOP mask, the software issues high PDOP warnings, pauses the time to initialize counter (PPK surveys), and suspends the measurement of a FastStatic point. Initialization and measurement resumes when the PDOP drops below the mask. The default value is 6.

Select the Tilt functions check box when using a GNSS receiver with an internal tilt sensor so that the Compensated point measurement method is available in the Measure screen and the Tilt warnings and Auto‑measure options are available in the appropriate point style settings. See Tilt sensors.

The broadcast message format generated by the rover depends on the selected survey type.

  • For real‑time kinematic surveys, the format of the broadcast message can be CMR, CMR+, CMRx, or RTCM RTK.

    The default is CMRx, which is a format used by the modern Trimble receivers. It is a compressed data format designed to handle the extra load of additional GNSS signals from modernized GPS, GLONASS, Galileo, QZSS, and BeiDou. Only use CMRx if all receivers have the CMRx option installed. To check if this option is installed in the receiver, select Instrument / Receiver settings on the controller that is connected to the receiver, see Operating several base stations on one radio frequency.

    To operate several base stations on one frequency, use CMR+ or CMRx.

    Some receiver firmware produced after 2018 obsoleted the use of RTCM RTK v2.X messages. If you attempt to use such firmware in the rover receiver, then the RTK survey will not start in Trimble Access because the receiver cannot decode incoming RTCM v2.x RTK messages. For more information, refer to the release notes for your receiver firmware.

  • For network RTK surveys, the broadcast message format can be from the following network RTK solutions: FKP (RTCM), VRS (CMR), VRS (RTCM), and RTCM3Net.
  • Networked single base RTK is also supported in the form of "multi station" surveys with both CMR and RTCM formats. These surveys enable you to connect to a network service provider by cellular modem or through the Internet, and receive CMR or RTCM data from the nearest physical reference station in the network.

  • For RTX surveys, the Survey type must be RTK and the Broadcast format must be RTX (SV) or RTX (Internet).

    If you select RTX (Internet), in the Rover data link screen select the GNSS contact you have set up for the RTX Internet service. This GNSS contact must have the Use RTX (Internet) check box selected and the appropriate Mountpoint name selected. See To create a GNSS contact for a rover Internet data link.

  • For real-time differential surveys, the Broadcast format must be RTCM for land‑based transmissions. For satellite‑based transmissions, select SBAS or OmniSTAR.

To use multiple base stations on one radio frequency, enter the first station index number you want to use in the Use station index field. For information about using multiple bases, see Operating several base stations on one radio frequency.

If you do not want to use multiple base stations on one frequency, enter the same station index number that you entered in the Base options screen.

To use any base station operating on the frequency set in the rover radio, tap Any.

If you tap Any and there are other base stations operating on the frequency, your rover survey could receive corrections from the wrong base.

When you use a receiver that supports multiple base stations on one radio frequency, the software asks you to specify the base to use when you start the rover survey. You can stop this question from appearing by clearing the Prompt for station index check box. The station index number in the Use station index field is used.

In a GNSS survey style, you can set the Station index for the base receiver to a number between 0 and 31, and you can set the Use station index for the rover receiver to Any or to the same number that the base is transmitting. When the rover station index is set to Any, the rover receiver will accept base data from any base. If you set the rover station index to match the same number as the base station index, the rover will accept data only from a base with the same station index.

The rover station default index value is Any. If you know your base station index, and you want to connect to only that base, make sure that you set the appropriate station index for the rover.

If the Prompt for station check box is selected, a list of base stations on your radio frequency appears when you start the survey.

When the radio link is down in a real‑time survey, the receiver can track and use signals from SBAS or OmniSTAR.

When you select the Auto tolerance check box, the software calculates horizontal and vertical precision tolerances that meet the GNSS receiver's RTK specifications for the baseline length you are measuring. To change the precision level at which point storage is acceptable, clear the Auto tolerance check box and enter the values that you want to use.

Enable Store RTK initialized only to store only initialized RTK solutions that meet the precision tolerances. Uninitialized solutions that meet the precision tolerances cannot be stored.

Disable Store RTK initialized only to store both RTK initialized and uninitialized solutions that meet the precision tolerances.

When using a GNSS receiver that supports Trimble xFill® technology, select the xFill option to continue surveying during base data outages of satellite-delivered correction data for up to 5 minutes. To use this option, your GNSS receiver must support xFill. xFill is not available if you have selected OmniSTAR as the fallback option in the Satellite differential field. See Bridging data outages using xFill.

With survey types that involve postprocessing, set the Logging device to the receiver or the controller.

To define the logging interval, enter a value in the Logging interval field. The base and rover logging intervals must correspond to (or be multiples of) each other.

When using an RTK and Infill survey type, the Logging interval is for the infill session only.

When using an RTK and data logging survey type, the Logging interval should be the same for each receiver – typically 5 seconds. The RTK interval remains at 1 second.

To define the logging file name, clear the Auto file names check box and then enter the file name in the Logging file name field.

Select this option to log raw data in the RTK part of an RTK & infill survey type. Use this option if you want postprocessed data stored as a backup to your RTK survey. When this option is selected, switching between Infill and RTK modes does not suspend logging.

To use observations from a GNSS constellation in a real-time or postprocessed survey, you must enable tracking for each signal type you want to use in both the Rover options and the Base options screens. See GNSS signal tracking options.