# Target tracking settings

In highly reflective environments, or on sites where multiple targets are in use, enable target tracking to ensure the instrument is locking onto the correct target.

Select the correct prism type and mode in the Targets screen to make sure the appropriate correction values are applied to the slope distance and vertical angle for geocentric offset and prism constant.

Target tracking is available when connected to a Trimble VX spatial station or Trimble S Series total station with search capabilities and using one of the following targets.

Trimble Active Track 360 target

The Trimble Active Track 360 (AT360) is a reflective foil target designed for use as an active tracker target. The AT360 includes a tilt sensor that enables eBubble support when connected to the controller with Bluetooth. The eBubble is used to check that the target is level. The tilt angle and tilt distance is stored with each observation.

For more information on connecting the AT360 to your controller, see Bluetooth connections.

When connected to the AT360, changing the Target ID in the Trimble Access software automatically updates the target ID setting on the AT360 once you tap Accept in the Target screen. If you change the target ID on the AT360 and the current target is an AT360, then the Target ID automatically updates on the controller.

Manual mode can be used if the battery in the AT360 needs charging and you do not have a replacement battery available. When using the AT360 in manual mode, Autolock is disabled and you must manually aim the instrument at the target.

When you enable Autolock and the current prism is the Active Track 360 then the software automatically switches the tracking mode to Active if it is in manual mode.

Trimble MT1000 MultiTrack target

When using the Trimble MT1000 MultiTrack target, to maintain constant lock to the correct target, set the Tracking mode to:

- Active when operating in a highly reflective environment or on a site with many prisms.

- Semi‑active when operating in a reflective environment and require precise elevations.

  When the tracking mode is set to semi‑active, the Target ID is used to track the prism, and then automatically switches to passive tracking mode when taking a standard measurement. This results in more precise vertical angle measurements.

If you do not operate in a reflective environment, set the Tracking mode to Passive.When passive tracking is used when measuring, be aware that there is a risk of nearby reflective surfaces interfering with the measurement.

The MultiTrack target should be used within the vertical angle tolerances shown:

Tracking mode | Vertical range
--- | ---
Active | +/‑ 15° from horizontal
Passive | +/‑ 30° from horizontal

Using the MultiTrack target outside these tolerances may degrade the accuracy of the measurement.

Trimble VX/S Series 360° prism or a custom prism

When using the Trimble VX/S Series 360° prism or a custom prism, set Check target ID to:

- Always when operating in a reflective environment and require precise elevations.

  The target ID is constantly checked to ensure that you maintain constant horizontal lock to the correct target. The prism is used to maintain the vertical lock.

  The target ID has two "on" modes; on for 60 seconds, and on continuously. When Check target ID is set to Always, you must set the target ID on the pole to "on continuously".

  When passive tracking is used to maintain vertical lock to the prism, you must be aware that there is a risk of nearby reflective surfaces interfering with the vertical tracking.

- Search and measure when operating in an environment with few reflective surfaces, but you want additional assurance when searching and measuring that the instrument is locking to the correct target.

  The target ID is checked when a search is initiated and again before a measurement is made to ensure that the instrument is still locked onto the correct target. If not, the software warns you so that you can perform a new search for the correct target ID.

  The target ID must be carefully aimed towards the instrument when taking a measurement.

- Search when operating in an environment with few reflective surfaces, but you want additional assurance when searching that the instrument is locking to the correct target.

  The target ID is checked after a search to ensure that the instrument is locked onto the correct target. If not, the software warns you so that you can perform a new search for the correct target ID.

  If Snap to target is enabled and the instrument automatically detects the target, the instrument does not perform a search or check the target ID.

  The target ID must be carefully aimed towards the instrument when performing a search.

- Off when not operating in a reflective environment.

When measuring rounds, make sure that each target in the rounds list can have a different target ID. These settings are retained for each individual target until the rounds observations are completed.

The target ID must be carefully aimed towards the instrument at all times.

For more information on how to configure the target ID on the Trimble pole, refer to the documentation for your instrument.

Trimble Precise Active target

The Trimble Precise Active target always works in active mode to maintain constant lock to the correct target. It cannot be used with an instrument that does not support active tracking. If the Trimble Precise Active target is selected as the current target and you then connect the software to an instrument that does not support active tracking, the software prompts you to select a different target.

The Trimble Precise Active target should be used at a vertical angle within +/‑ 15° from horizontal. If the vertical angle is greater, tilt the target toward the instrument.

T-360 LED or T-360SL LED target

The T-360 LED or T-360SL LED target is a reflective foil target designed for use as an active tracker target. The T-360 LED and T-360SL LED targets are available only in Japan.

Set the Target ID using the dial on the top of the target and then set the Target ID field in the software to match the identification number on the target.