GNSS measurements are taken using the SiteVision GNSS. GNSS is shown in green. When you measure in GNSS mode, the measurement is taken at the location of the antenna, and the pole height and antenna offset are applied.

To take a measurement using GNSS:

1. With your required measurement app active (bottom center of the screen), tap it.

2. On completion of the measurement a blue marker (10 cm diameter sphere) appears in the model. The position in local coordinates and latitude / longitude / height is displayed.

   TIP – To discard the measurement, tap the delete button in the bottom right corner of the results dialog.

Once a measurement has been made the Sync icon appears on the right side of the main screen. When you use the Sync function, measurements are sent for processing to:

• Trimble Connect, if you loaded your model from Trimble Connect. The first time you send measurements to Trimble Connect you will be asked for a name for the .csv file. There is only one .csv file per model. Each time you sync your measurements the revised file updates Trimble Connect.

• the SV Measurements folder on your device, if you used the Load Model / My Files option. The first time you sync measurement you will be asked for a name for the .csv file. There is only one .csv file per model. Each time you sync your measurements the revised file is updated.

EDM measurements use the integrated range finder module located under the antenna in the SiteVision system. EDM measurement mode is shown in orange and requires a Bluetooth connection between your mobile device and the SiteVision system (the connection will be established automatically).

If there are multiple SiteVision units being operated in a small area, such as for training, it is important to power up and connect each unit in sequence.

1. Start one unit and complete the connection to the EDM as above, then

2. Start the second unit and complete the connection to the EDM.

3. Repeat for each unit.

   The SiteVision unit connects to the first available (unpaired) EDM unit it finds, so failing to follow the procedure above may result in the device mounted on unit A connecting to the EDM in unit B or unit C.

To initiate EDM measurements, tap the active measurement app (bottom center of the screen), or tap the cross-hairs.

• When EDM measurement is turned on the EDM measures continuously to get an estimated range to the target. This estimated range is used to automatically align the sighting cross-hairs to account for the offset between the camera lens and the EDM lens in the SiteVision positioning system.

• The cross-hairs appear as red or white, as follows:

  the cross-hairs are red when...	the system is re-aligning the cross-hairs.
  	the EDM doesn't return a valid distance measurement (e.g. if pointing to the sky, or to some surfaces that it can't easily measure to, such as glass or reflective surfaces).
  the cross-hairs are white when...	the cross-hairs are aligned with the target, indicating that the EDM and the cross-hairs are aligned at the same target.

  NOTE – To generate coordinates for the remote point the SiteVision system uses the orientation derived from integrating the GNSS and the AR vectors. For best accuracy, walk toward the point to be measured for a few meters / yards before taking the measurement. Stopping and then rotating quickly will reduce the orientation accuracy to the level of the AR visual tracking and may result in a significant error in the horizontal position.

• TIPS –  

  • For more accurate operation, steady the device; using it on a short range pole can assist with this.

  • Accuracy is also dependent upon the GNSS position so ensure that you have a high accuracy GNSS position when measuring to remote objects.

  The EDM unit has a range of up to 100 m (300 ft) depending on the target type surface and lighting conditions, but for accurate operation (< 20 cm / 8 inches) Trimble recommends that you use it at range of 0.5 m to 10 m (1.5 ft to 30 ft), or up to 25 m (80 ft) to record features requiring lower accuracy (such as trees).

Depending on the reflectivity of the surface, steadiness of pointing and other factors, you may get a message indicating that the measurement has failed. Either repeat the measurement, move closer to the point and re-measure, or try measuring from a different angle.

Real World LiDAR and Camera measurement modes are shown in orange.

Real World measurements measure a point in the real world, captured in the coordinate system of the model you have loaded. The measurements are based on the technology of the device being used. For most devices this is based on visual odometry, calculating distances using camera images and sophisticated algorithms. Some more modern devices include a LiDAR sensor, which allows for much more reliable and accurate measurements. However even with LiDAR, the range tends to be limited to approximately 5 meters (5.5 yards). SiteVision will automatically detect and use the best available Real World measurement method.

To initiate LiDAR or Camera measurements, tap the active measurement app (bottom center of the screen), or tap the cross-hairs.

• The cross-hairs appear as red or white, as follows:

  the cross-hairs are red when...	Sitevision is unable to return a valid distance measurement (e.g. if pointing to the sky, or to some surfaces that it can't easily measure to, such as plain vertical walls with no defining features, or glass / reflective surfaces).
  the cross-hairs are white when...	a valid distance measurement is able to be returned (edges of objects, or patterned surfaces will provide more reliable results for Camera based measurements. LiDAR enabled devices should perform well in most circumstances).

• Both Camera and LiDAR measurements have a limited range of approximately 5 meters (5.5 yards). Beyond these ranges it becomes very difficult to achieve a valid measurement.

Model-based measurements use the Google AR or Apple ARKit functionality to measure to a point directly within the 3D visualization.

To initiate Model measurements, point the cross-hairs at the point in the model you want to measure to, then tap the active measurement app (bottom center of the screen), or tap the cross-hairs.