mmGPS Initialization

The procedure of initialization of mmGPS+ systems includes two steps:

  1. Connect the controller and transmitter. Calibrate the transmitter with the correct channel and communication port and also set up the transmitter's height and locate it at the jobsite. Learn more about that from Transmitter Data and Transmitter Position.
  2. Unplug the controller from the transmitter. Connect the controller and GNSS receiver to initialize the Sensor.

Note: Perform sensor initialization every time the sensor (or GNSS receiver it is connected to) is unplugged from the setup due unexpected shutdown (drained battery, etc).

Click to display additional functions:


Transmitter Position Sets

The Transmitter Position Sets window displays the list of transmitter position sets that exist in the current job and allows to quickly switch between them. A transmitter in a specific location on the jobsite is called the Channel. A transmitter position set supports up to four channels.


Transmitter Position Set

The Transmitter Position Set dialog window allows you to add new or change existing set of transmitter positions. Fill in the fields:

After performing changes to a transmitter position set and closing the dialog with the button you will be prompted to reinitialize the sensor. If you confirm the reinitialization, sensor will be initialized automatically or you will be taken to the respective dialog - depending on the changes you have made. If you selected not to initialize the sensor with changed settings, the changed settings will be saved to the current job.


Transmitter Data

The Transmitter Data screen allows you to add new or change existing transmitter configurations.

The transmitter list contains the following fields:

Available operations are:


Transmitter

To add a connected transmitter or change the information on the existing transmitter:

  1. Enter the name of the transmitter in the SN field.
  2. From Com Port, select the communication port of the controller that is used for connection with the transmitter.
  3. Click Get Data to retrieve the transmitter's data.
  4. Select Connect to last used BT device for automatic connection. The option is available only when Bluetooth is selected in Com Port.
  5. Click .

If required, click Clear Data to clear the data fields.


Transmitter Pos

The Transmitter Pos screen allows you to set up the transmitter's height and its location at the jobsite.

The transmitter position list contains the following items:

Available operations are:


Known Point

To set up the transmitter over a known point:

  1. Select the Point the transmitter is installed over. It can be selected using the map or list buttons.
  2. Select the transmitter from the Name drop-down list. The channel ID will be displayed.
  3. Specify the height of the transmitter by either of the following ways:
  4. Apply Known Pt Offset: Once the known point offset is measured and accepted in mmGPS setup, you may need to zero it after checking onto another control point. For that, deselect this option. This allows you to do such checks without deleting laser setup and going through the setup process again.

    Note that you apply known point offset for selected transmitter / channel only. The calculated offset value can be recalculated in the Known Pt Offset dialog and then applied (or not applied - that is, if you perform recalculation for checking purpose) to the transmitter / channel.

  5. Click .

Init Sensor

To upload transmitter calibration information to the sensor and set up the sensor for receiving the transmitter's laser beam:

  1. Select the Receiver Port that connects the receiver and sensor.
  2. From Transmitter ID, select the transmitter's channel. The ANY selection will allow the sensor to independently select the transmitter with the smallest error rate.
  3. Select the Sensor Gain to set the sensitivity of the sensor to the transmitter's laser beam.
  4. The Firmware Version for the sensor is shown.
  5. Click Init Sensor to start initialization process.

Note: Perform sensor initialization every time the sensor (or GNSS receiver it is connected to) is unplugged from the setup due unexpected shutdown (drained battery, etc).


Resect mmGPS+

To measure an unknown transmitter location using the rover and three or more points:

  1. With the controller and sensor connected, set up the sensor. More...
  2. Perform resection measurements. More...
  3. Observe calculated data. More...

Sensor

To set up the sensor for measurements:

  1. Select the Receiver Port that connects the receiver and sensor.
  2. From Transmitter ID, select the transmitter's channel. The ANY selection will allow the sensor to independently select the transmitter with the smallest error rate.
  3. Select the Sensor Gain to set the sensitivity of the sensor to the transmitter's laser beam.
  4. The Firmware Version for the sensor is shown.
  5. If Known Trans Horz Pos is selected, the Known Point dialog displays. Select the point over which the transmitter is setup.
  6. Click Init Sensor to start initialization process.

Resect

To perform the measurements from the rover point to the point over which the transmitter is set:

  1. Observe the information about the current state of measurement displays:
  2. If using an unknown point, click .
  3. If using a known point:
  4. During the measurement, the Logging field displays the counter of the epochs collected.
  5. The Meas field shows the number of measurement.
  6. When the desired amount of epochs is achieved (it must be at least 3), click .
  7. Move to the next point and repeat measurement steps for it. You must take measurements on at least 3 points.

Data

On this tab:

  1. View the results of resection calculation. Data will display only after three or more points have been measured.
  2. Click Re-Meas to re-measure a point if required.
  3. If the resection values are acceptable, click Accept and view the point information for the transmitter.
  4. Enter any other desired information and click to save the transmitter's point information.

Field Calibration

The Field Calibration function fixes errors in incline in the transmitter's self-leveling mechanism.

To perform field calibration:

  1. Set the transmitter into calibration mode. To do this, hold the plumb beam key, then press and release the power key.
  2. Connect the controller and sensor. Face the sensor towards the transmitter at the distance of several feet. Ensure that the sensor remains steady throughout the calibration process.
  3. The Transmitter Name displays.
  4. Click Next. A wizard will guide you through the calibration process - just follow the instructions.

    Note: The Calibrate button will be grayed out while the "Auto-Leveling in progress. Please wait..." line is displayed. When the auto-leveling is complete, the line disappears, and the button becomes enabled.

When the calibration completes, Update Calibration Data if required.


Update Calibration Data

The Update Calibration Data dialog displays after performing Field Calibration if it is determined that the transmitter leveling offsets need to be adjusted.

To update the calibration data:

  1. Disconnect the controller from the sensor and connect with the transmitter.
  2. Select the Communication Port that connects the controller and transmitter.
  3. Click Update Data to send the offsets information to the transmitter. MAGNET Field uploads the calibration data to the transmitter and automatically turns off the transmitter.
  4. When finished, close a successful message and initialize the sensor. More...

Known Point Offset

The Known Point Offset function is used to compute the height offset between the rover and a currently occupied known point. This can be used as an adjustment for the transmitter height.

  1. The Transmitter Name field allows you to select the transmitter and channel for which you perform the known point offset configuration. Every time you switch between transmitter/channel in this list, the settings currently configured in the Transmitter Pos dialog are sent to the sensor.
  2. Specify the necessary offset by any of the following ways:
  1. Enter the Antenna Height and set the type of height measurement (vertical or slant).
  2. The Num Epochs field displays the number of GNSS epochs used in the measurement.
  3. Click to start the measurement process. After pressing, the button changes to , and the counter of the epochs collected appears. You should wait until the epochs collected are averaged. Click to cancel.
  4. When the averaging completes, the Height Offset will display the difference in height between the known measurement and the current rover measurement (the value set in the Known Point dialog is already taken into account).
  5. Click , then Yes in the warning dialog to adjust the transmitter height using the offset. This offset will be added to the transmitter's height.
  6. When finished, initialize the sensor. More...

Advanced Sensor Options

In the mmGPS+ Options block you can:

  1. Select the Init Time Improvement check box to improve the RTK fix time for the receiver.
  2. The Weighted Height check box is selected by default to use the weighted height values from GNSS and mmGPS+ measurements.