Target Measurement

This article will cover how to perform a Target measurement while using Collage Site.

The target measurement dialog is used to measure targets for OCC/BS, Resection, generic Target measurement, and Survey New Point workflows. Instrument control is accomplished using either Touch Drive to aim the instrument, and the yellow + and - buttons to zoom in and out.

  • For the GLS: Zoom uses both the wide angle and telephoto cameras on the GLS depending on the zoom level.
  • For the GTL: Only a wide-angle camera is available for rough aiming digitally, but you can also manually sight the instrument using the peek/scope on the GTL and the dials. This is necessary for longer range target aiming on the GTL.

The Target Measurement dialog on the right side of the screen is used to input Target Measurement settings and control parameters relevant to each target.

Prism Tracking is only available on GTL

Workflow

Begin by setting the target measurement parameters in the right-hand panel:

  • Target Type: This determines how the instrument measures the target, so ensure you make the correct selection.
  • Prism Constant Correction: Prisms and some other types of targets have an offset value that must be entered for a correct measurement. Make sure this matches the value for the prism/target you are using. Each type of target has its own default settings for Prism Constant Correction.
  • Target Height: If your prism or target is offset above a known point on a pole or tripod, enter the target height.
  • Target Distance: If the target is placed within 5 meters of the scanner, the display error of the reticle on the camera image will be significant. In this case, select Close to reduce the display error. If the target is more than 5 meters from the scanner, set this value to Far.
  • Laser Pointer: Turns the visible laser on/off to assist in target measurement as necessary.
  • Search Angle: Changes the size of the search radius for the target. A large search angle will result in longer target measurement times, but requires less precise picking of the target location on the screen. The outer circle on the targeting reticle indicates the current size of the search radius.
  • Flashlight: This is a GLS-only setting. Flashlight allows you to detect a single element prism quickly and perform a measurement.
  • Free Mode: This is a GLS-only setting. When free mode is on, you can manually rotate the scanner instrument.



First, manually rotate the scanning instrument and roughly point it towards the target you want to measure. Then, tap the target point with your finger on the camera image to bring the reticle closer to the target.



Adjust zoom level by using the +/- buttons as needed to see the target clearly. Then, adjust the reticle position to be close to the target by tapping the target on the camera image.

When using the GLS-2200, the first zoom level uses the wide angle camera and the other zoom levels use the telephoto camera. You can switch to the telephoto camera by tapping the + button once.

When using the GTL-1200, only three zoom levels for the wide angle camera are available. Longer distance target aiming should be done by using the instrument’s sight instead of Collage Site Touch Drive.



Adjust the size of the Search Angle so that the outer circle of the targeting reticle is completely around the outside of the target. If the target is only partially within this circle, target measurement will fail. Once you are ready, tap the Measure button to commence target measurement.



Once target measurement has been done, double check if the scanner measured the target correctly by using camera images or tele scope of GTL-1200. Additionally, Collage Site’s screen should zoom in on the target after a successful measurement. If it succeeds, choose the Keep option. Otherwise, choose the Discard option to try again.

Note

When using a GLS-2200, please use the appropriate target sheet and the search angle according to distance to the target being measured. If these are not correct, it could be lead to failed target measurements even if you do everything else correctly.

When using target sheets

Distance to the measuring target (m) Search angle Target sheet
2 - 5 2.5 Small
5 - 10 1.0 Small
10 - 20 1.0 Small, Medium
20 - 50 0.5 Small, Medium
50 - 100 0.5 Medium, Large
100 - 200 0.5 Large

*Small: 3cm, Medium: 6cm, Large: 12cm

When using prism

Distance to the measuring target (m) Search angle Prism
10 - 25 1.0 Prism-2, Prism-5, ATP 1/2
20 - 50 0.5 Prism-2, Prism-5, ATP 1/2
> 40 0.2 Prism-2, Prism-5, ATP 1/2

Supported Target Types