Position

This page shows general information about the current position solution derived from satellite measurements.

Select Receiver Status / Position.

 

Position

Shows the current position solution.

  • Lat – Latitude in degrees, minutes, and seconds.

  • Lon – Longitude in degrees, minutes, and seconds.

  • Hgt – Height above the ellipsoid to the Antenna Phase Center in meters.

    CAUTION – The position output by the receiver is the Antenna Phase Center position. You may want to reduce this position to a reference position elsewhere. If so, you should account for any tilt of the antenna in such a reduction. The settings for the Antenna Measurement Method and Antenna Height are not applied to this output.

  • Type – Current position type.

    • Old – No updated position available.

    • Autonomous – Position has no satellite corrections applied.

    • CLAS – Position using QZSS CLAS corrections.

      QZSS CLAS provides centimeter-level nationwide positioning PPP-RTK correction service for Japan. Compact SSR correction format broadcast at 2,000 bps on the QZSS L6D signal. QZSS CLAS supports multi-GNSS including GPS, Galileo, and QZSS. Use firmware version 6.26 or later and enable QZSS L6D on the Tracking screen.

      QZSS CLAS

      Static (95%)

      Kinematic (95%)

      Horizontal accuracy

      ≤ 6 cm

      ≤ 12 cm

      Vertical accuracy

      ≤ 12 cm

      ≤ 24 cm

    • Code Diff – Code differential solution – typically a single-frequency solution.

    • Phase Diff – Carrier phase differential solution (also known as Real-Time Kinematic (RTK) solution), typically a dual-frequency solution.

    • OmniSTAR VBS – Position using OmniSTAR VBS satellite-based correction service.

    • OmniSTAR XP – Position using OmniSTAR XP satellite-based correction service.

    • OmniSTAR HP – Position using OmniSTAR HP satellite-based correction service.

    • OmniSTAR HP+G2 – Position using OmniSTAR HP and G2 satellite-based correction service.

    • CDGP – Position using the Canadian DGPS corrections.

    • SBAS+ – Position using the SBAS Plus corrections.

    • SBAS – Position using SBAS corrections.

    • GVBS – Position using the clocks and orbits information from RTX corrections to augment the autonomous solution.

    • RTK and Location RTK – Carrier phase double difference position correction service.

    • RTX – Position using Trimble CenterPoint RTX satellite-based or IP correction service.

    • xFill – Position using Trimble xFill® RTK augmentation service (5 minute duration limit).

    • xFill-RTX – Position using Trimble xFill RTK augmentation service with unlimited duration. Service requires a CenterPoint RTX subscription.

  • Precision – Displays the precision capability of the receiver.

  • Datum – Displays the datum that the position is referenced to.

Velocity

Shows the apparent velocity of the receiver derived from the difference of the current position relative to the previous position.

  • North – The apparent velocity in the grid north direction, in meters per second.

  • East – The apparent velocity in the grid east direction, in meters per second.

  • Up – The apparent velocity in the vertical direction, in meters per second.

NOTE – A stationary receiver shows some velocity due to minor differences in the position solution each time it is computed. The receiver must be moving for these values to be meaningful for anything other than general status information.

Position Solution Detail

Shows the following information:

  • Position Dimension –

    • Clock Only – Accurate time is computed.

    • 1D – Vertical position only is being computed.

    • 2D – Horizontal position only computed.

    • 3D – Horizontal and Vertical position computed.

  • Position Engine –

    If the solution is Autonomous GPS or DGNSS, then you will see these fields. This is the DGPS or DGNSS engine used to calculate the differential position solution and is not available for an RTK or RTX position. For configuration options refer to Autonomous/Differential Engine and Dynamic Model configuration in the Receiver Configuration / Position page.

    • Kalman – By default, the Kalman filter is enabled. This results in a higher quality position solution for autonomous or DGPS solutions when compared with a Least Squares solution. The Kalman selection works substantially better than a Least Squares solution in a mobile vehicle when there are frequent satellite signal dropouts around bridges or high buildings, and gives improved performance around forested areas.

    • Least Squares – If Least Squares is enabled. A Kalman solution uses the time history of the position and velocity it has created, whereas a Least Squares option does not use the time history. Trimble recommends that you use the Kalman filter. The Least Squares option is available for rare cases if you decide to trial it.

  • Motion Info – Only available for an RTK position solution.

    • Roving – Antenna can be in motion or static. Also known as Kinematic.

    • Static – Antenna is known to be static. This does provide some improvement in accuracy for RTK applications. When the receiver is in static mode, the antenna should not move at all.

  • Augmentation – Shows which constellations are used in the position solution.

    • GPS – GPS satellites.

    • GLN – GLONASS satellites.

    • BDS – BeiDou satellites.

    • GAL – Galileo satellites.

    • SBAS – Satellite Based Augmentation Systems such as:

      • WAAS (North America)

      • EGNOS (Europe)

      • NavIC (India)

    • QZSS – Quazi Zenith Satellite System (Japan).

    • NavIC – NavIC satellites (India).

  • RTK Solution – Only available for an RTK position solution.

    • Normal – Normal dual-frequency RTK solution.

    • L1 Only – Solution uses L1 frequency only.

  • RTK Init – Only available for an RTK position solution.

  • RTK Mode – Only available for an RTK position solution.

    • Synchronized – Position updates are synchronized with the appropriate CMR input, which is subject to the latency of the transport (radio).

    • Low Latency – Base measurements are predicted so that position updates are generated with only minimal latency (20 ms).

    • N/A– Non-RTK position.

  • RTK Network Mode – Only available for an RTK position solution.

    • Single Base Line – Single RTK base station.

    • Network – Such as the Trimble VRS Network.

    • Global – Such as the Trimble RTX global correction service.

  • Age of Corrections – If differential corrections are being used, the age of the differential corrections, in seconds, at the time of the shown position fix.

  • SBAS PRN – If the receiver is in SBAS mode (WAAS/EGNOS/ etc), this shows which of the tracked SBAS satellites the receiver is using corrections from to generate the corrected position.

  • Height Mode –

    • Normal – Not constrained by height input.

    • Constrained Height – An external height constraint for the antenna position. The receiver will produce a height value within the constraints provided by the external application.

  • xFill Status –

    • Running – xFill is in operation. The Web interface displays xFill in the position type instead of RTK position type. If xFill runs for more than five minutes, this xFill status will display the Ready status while position type will no longer be xFill.

    • Ready – The offset between the RTK datum and the xFill datum has been determined and the receiver can go to xFill positioning if the RTK position is ever lost. It shows Ready even if your receiver does not have xFill installed, but is tracking the RTX satellite.

    • Not Ready – The offset between the receivers RTK datum and the xFill datum has not yet been determined. It typically takes 10 minutes of concurrent RTK positioning and tracking of the RTX satellite for this to go to the Ready status. It can also mean the xFill satellite is not being tracked or the OmniSTAR tracking has been selected.

    • Not Available – That means the receiver is not capable of offering this service.

  • Correction Controls –

    • Off – There are no user-defined correction controls.

    • On – User-defined correction controls are active.

      • For more information, see Correction Controls.

  • RTX Status – Indicates what RTX satellite beam you are tracking and connected to receive your correction.

  • IonoGuard – IonoGuard is ionospheric mitigation to help the receiver with tracking high-solar activity. See the General web page.

Satellites Used

Shows the list of satellites used in the current position solution. Satellites may be tracked by the receiver but not used in the position solution. Satellites may not be used if no ephemeris available, measurements do not meet the receiver's quality requirements, or differential correction data is not available.

Satellites Tracked

Shows the list of all satellites being tracked by the receiver. Some of the satellites tracked may not be used in the position solution. The number of satellites tracked by each antenna is shown in brackets.

Receiver Clock

Shows information about the receiver clock performance.

  • GPS Week – Current GPS week. Incremental number of weeks, starting at 0 hour UTC on the date January 6, 1980.

  • GPS Seconds – Current time in GPS seconds. Incremental number of seconds, starting at 0 hour UTC on the date January 6, 1980.

  • Offset – The difference between the current time as reported by the clock and the time derived from the GPS position solution.

  • Drift – The rate at which the receiver clock is drifting from the time derived from the GPS position solution.

Multi-System Clock Offsets

Shows information about the time differences between the clocks used by different satellite systems.

  • Master Clock System – The satellite system clock being used by the receiver.

  • GLONASS Offset – The offset between the master clock and the GLONASS clock when GLONASS satellites are being tracked.

  • Galileo Offset – The offset between the master clock and the Galileo clock when Galileo satellites are being tracked.

  • BeiDou Offset – The offset between the master clock and the BeiDou clock is changing when BeiDou satellites are being tracked.

  • GLONASS Drift – The rate at which the offset between the master clock and the GLONASS clock is changing when GLONASS satellites are being tracked.

  • Galileo Drift – The rate at which the offset between the master clock and the Galileo clock is changing when Galileo satellites are being tracked.

  • BeiDou Drift – The rate at which the offset between the master clock and the BeiDou clock is changing when BeiDou satellites are being tracked.

  • NavIC Drift – The rate at which the offset between the master clock and the NavIC clock is changing when NavIC satellites are being tracked.

Dilutions of Precision

Shows information about the strength of the satellite constellation with respect to a specific position attribute. The various DOPs take into account the location of each satellite relative to other satellites in the constellation, as well as their location relative to the receiver. Low DOP values indicate a higher probability of precision (lower precision dilution).

  • PDOP – Position DOP, indicates the strength of the satellite constellation for general position precision.

  • HDOP – Horizontal DOP, indicates the strength of the satellite constellation for horizontal position precision.

  • VDOP – Vertical DOP, indicates the strength of the satellite constellation for vertical position precision.

  • TDOP – Time DOP, indicates the strength of the satellite constellation for determining time and the clock offset.

Error Estimates (1-Sigma)

Shows the variation of the current position with a 68% confidence.

  • North – The apparent variation of the receiver position in the grid north direction, in meters.

  • East – The apparent variation of the receiver position in the grid east direction, in meters.

  • Up – The apparent variation of the receiver position in the vertical direction, in meters.

  • Semi Major Axis – The semi major axis of the error ellipse.

  • Semi Minor Axis – The semi minor axis of the error ellipse.

  • Orientation – The orientation of the major axis of the error ellipse.

Current Date/Time

At the very bottom of the page the current UTC date and time is displayed in the format YYYY-MM-DDTHH:MM:SSZ (UTC).