Edit Target: Leica

Total Station Toolbar | Target Manager | Target List | Edit

Use this option to edit an existing user-defined target or edit a copy of a Leica instrument target. You will also see this display after you copy an existing target. Leica uses a different prism offset method than other manufacturers and you should familiarized yourself with how they are computed. See the Leica Constant section below for more information.

Target Name

Use this field to either edit or enter a new and unique name for the target you are editing.

Target Type

There are two target types available. Prism is to be used when you are selecting a target that has a known offset or prism constant. This can be a round prism, 360, mini, etc. RL stands for reflectorless and you should select this target type if you are using an instrument that is reflectorless capable, and you do not wish to or cannot use a designated reflector.

Prism Icon

When creating Leica instrument targets, the prism icon must be User Entered, and that's why you are not permitted to edit the target's icon. This is a Leica instrument requirement and therefore cannot be changed.

Leica Constant (mm)

Leica prism constants differ from non-Leica prism constants. In summary, Leica’s prism constant of 0mm is equal to -34.4mm absolute prism constant relative to the plumb line. A simple formula to explain the relationship:

Leica Constant (for non-Leica prisms) = Absolute Constant + 34.4mm, or

Absolute Constant (for Leica prisms) = Leica Constant – 34.4mm

Examples:
  1. SECO -30mm offset prism
    1. Leica Constant = -30mm + 34.4mm = 4.4mm
    2. Absolute Constant = -30mm
  2. SECO 0mm offset prism
    1. Leica Constant = 0mm + 34.4mm = 34.4mm
    2. Absolute Constant = 0mm
  3. Leica GPR1 round prism
    1. Absolute Constant = 0mm - 34.4mm = -34.4mm
    2. Leica Constant = 0mm
  4. Leica GRZ4 360° prism
    1. Absolute Constant = 23.1mm - 34.4mm = -11.3mm
    2. Leica Constant = 23.1mm

It is strongly recommended that you test your use of prism constants on a known baseline to be sure that your non-Leica prism is in the true zero prism system.

Absolute Constant (mm)

The Absolute Constant or more commonly known as the Prism Constant defines the relation of the distance measurement to the mechanical reference point of the reflector. Use the formula in the Leica Constant section above to calculate the Leica constant. Enter that value in the Leica Constant field and see the Absolute constant be automatically computed for you.

Save

Press this button to store your target edits. Targets are stored to the Settings.xml file, and you are returned to the Target List screen.

Cancel

Press this button to cancel creating a new target. You will be returned to the Target List screen.