Backsight

The backsight wizard helps you specify a reference direction of a Total Station survey.

  1. In the Occupation Point group you can:
  2. In the Backsight Point group you can:
  3. Note: If the occupation point has no elevation (i.e. is a 2D point), the backsight point measured using azimuth will have no elevation. As the result, all topo points measured with this setup will also have no elevation.

    If you have entered a new backsight point, the software prompts you to enter the point coordinates in the Add Points dialog before starting of measurement.

  4. Select the Observation info check box to open the Observation info dialog, where you can enter meteo data during the session.
  5. Click the Next button to continue.
  6. Check the setup settings:
  7. The Set Circle to field displays the horizontal circle reading corresponding to the backsight point. The icon brings up the floating menu that enables you to set BS Circle value to zero or azimuth, to input a value or to get from the instrument, or to change the value by +/- 90 or 180 degrees. The software retains the previous setting for this drop-down list.

    To turn a Robotic total station to the Backsight Point, click the To BS button.

    Select Measure Distance if required to measure the distance to backsight point.

    If required, click the Check button to take the measurement to the backsight point and then view the results.

  8. Click the Set button to set the horizontal circle on the instrument as defined in the BS Circle field, take the measurement to the backsight point and then Review the results. If required, click to save the results into a *.txt file.

  9. In the EDM Mode you can select the distance measuring mode. Depending of the device model you can see following sets:
  10. You can find the accuracy values for the selected mode in the operators manual for the given robot for the reflectorless survey.

    Also you can select one of the available methods of distance measurement , for instance, Prism, Sheet, Non-Prism, or Long Non-Prism. The selection depends on the instrument you use.

  11. Click to observe and change the survey settings, if required. More...
  12. The icon brings up the pop-up menu of additional options. More...

Click the icon provided a robotic total station is used to toggle between the status bar and the tool bar for remote control of the instrument. More...


User Scale

Enter the required value of the scale.


Pop-up menu

Additional options which can be useful are as follows:


Station and Offset

The Station and Offset dialog allows the backsight or occupation point to be determined by the station, offset and elevation in relation to a road.

To determine the point:

  1. Click and select the referenced alignment that can be a Road or Horizontal Alignment.
  2. Enter the Station along the road where this point should occur. You can select any road point as a current point. To do it, click in this field and select any road point in the Road Point dialog.
  3. Enter the Offset from the road where this point should occur.
  4. Enter the Elevation of the point.
  5. Click to open the Add Point dialog on which to add the calculated point to the list of points. The BS dialog opens with this occupation point.

Multiple Backsight: Normal view

The Multi-Point BS: Normal dialog allows you to verify the location of the occupied point.

Take the measurements to a number of BS points:

  1. Enter the first known Point name.
  2. The Code field displays the point's code.
  3. Enter the height of the reflector. Type the value manually or click the button with current reflector icon to select one of the previously used values from the context menu. If prism is used as a target you can also quickly review or change its configuration: select Edit from the context menu to open the Prisms dialog.
  4. Take measurements. More...

Multiple Backsight: Measurement Set view

The Multi-Point BS: Meas Set dialog displays measurements being done during one set:

Available buttons:


Multiple Backsight: Map view

The Multi-Point BS: Map tab displays the occupation point, the backsight point(s) and all measured points in the graphical view. In the dialog you can take the measurements to selected of BS point. To do it, you need all steps described for the Multi-Point BS: Normal dialog.


Taking Measurements

Depending from the selected instrument type, MAGNET Field offers the following ways to take measurements.


Conventional Total Station

When using the Conventional Total Station you may save the single measurement, or you may also perform single measurement to the point; verify the result on the screen and after that save it.

Note: For both these ways you can select either Fine or Rapid (Coarse) distance measuring mode.


Robotic Total Station

The Robotic Total Station automatically takes the measurement to the target. There are two buttons in the dialog:

After you have measured a point with the instrument, the button becomes enabled. It allows you to perform pole measurement, if required.

Read more about Pole Measurement...


Resection

The method of resection allows you to determine the location of the Total Station occupation point by measurement of the known points.

The resection wizard helps you to perform the resection:

  1. In the Define instrument setup group you can:
  2. Click the Next button to continue.
  3. In the Specify a control point group you can:
  4. Repeat the procedure for the remaining known points.
  5. After saving the second and subsequent points, the Results screen displays measured value of angles and slope distances with estimate of accuracy. If the resection cannot be solved, the respective message will be displayed.

    In this screen you can:

    Click the Advanced button to find the details of resection solution and recommendations in case of unsuccessful solution. In the advanced view of the dialog, additional functionality is available:

  6. When you have measured sufficient resection points, the Find button becomes available next to the Point field. Selecting a point and clicking Find will open the Find Resection Point dialog. In this dialog:
  7. After finishing the resection procedure you can add a new measurement for the given occupation point. Click and perform a new TS measurement.
  8. By using Resection Options you can select resection either in the horizontal plane only (2D) or the horizontal and vertical plane (Resection 3D).

    If you activated Hybrid Positioning™ mode, the Resection for this mode will prompt to perform TS and GNSS measurement for the point.

    Note: When at least one point in 2D-type resection has height, the result point is a 3D point with a 0.0 height. When measuring all points with no height, the result is a 2D point.

    The icon brings up the pop-up menu of additional options. More...


Resection 3D

To calculate the default three dimensional resection, minimum two points with distance measurements are required. With angle-only measurements, three points are required. If additional points are measured, a least-squared solution is used. To change the type of resection to use only horizontal coordinates (2D), click and select Resection Options from the pop-up menu. The 2D/3D option is retained between sessions. When doing a resection next time, the resection will start up with the previous used setting.

To perform the resection, see the steps in the Resection. The Results screen displays the result of the sideshots being done.

The icon brings up the pop-up menu of additional options. More...


Resection in Hybrid Positioning™ mode

The Hybrid Positioning™ mode allows you to simultaneously record the point coordinates from GNSS rover receiver and Total Station to the opened job. This option can be activated only for Robotic Total Station with reflector. The GNSS receiver and Robotic Total Station are connected to the job. Using Hybrid Positioning™ mode you can obtain an occupation point coordinates in Grid or WGS-84 coordinate systems.

Before performing resection you need activate Hybrid Positioning™, select desired prism and select Hybrid Positioning™ antenna offset check box and open Resection dialog.

There are following scenarios to perform the resection procedure:

Scenario A:

The desired Grid projection is defined in the job. Grid to Ground transformation is not selected. The GNSS and TS measurements are performed for each unknown point. The coordinates of the Occupation Point are calculated in the current Grid coordinate system.

  1. Select the desired Grid projection in the Coordinate System dialog.
  2. In the Define instrument setup group (Resection dialog) you can:
  3. Click the Next button to continue.
  4. In the Specify control point group you can:
  5. In the Measure GNSS Point For you see the point coordinates in the current Grid are measured by the GNSS receiver. In this group you can:
  6. After saving second unknown point (and subsequent point ) the Results screen displays measured value of angles and slope distances with estimate of accuracy. In this screen you can:

  7. After finishing the resection procedure you can add a new measurement for the given occupation point. Click and perform a new TS / GNSS measurement.


Scenario B:

The desired Grid projection is defined in the job. Grid to Ground transformation is selected. The relationship between Grid and Ground coordinate systems is known. Coordinates for both coordinate sets are displayed in the current coordinate system. The coordinates of the Occupation Point are calculated in the Grid or Ground coordinate systems.

The routine of the resection procedure is equal previous scenario.

  1. Select the desired Grid projection in the Coordinate System dialog.
  2. Click the Use Grid/Ground check box, click and select the desired parameter (Parameters) in the Grid/Ground Parameters dialog. Click to save the selected grid to ground parameters.
  3. Perform the steps 2-6 in the previous scenario.

Scenario C:

The Grid projection is not defined in the job. The user has coordinates of the control points (two points at least) in the Ground coordinate system. For each control point TS and GNSS measurements are provided. The software performs the localization between WGS-84 and Ground. The coordinates of the Occupation Point are calculated in the Ground and WGS-84 coordinate systems.

  1. Select <none> in the Projection of the Coordinate System dialog.
  2. In the Define instrument setup group (Resection dialog) you can:
  3. Click the Next button to continue.
  4. In the Specify control point group you can:
  5. In the Measure GNSS Point For you see the point coordinates in WGS-84 are measured by the GNSS receiver for localization. In this group you can:
  6. After saving the second known point (and subsequent point ) the Results screen displays measured value of angles and slope distances with estimate of accuracy. In this screen you can:

Scenario D:

The coordinates of the control points (two points at least) in the Ground coordinate system imported in the job. The desired Grid projection is defined in the job. For each control point TS and GNSS measurements are provided. The software automatically performs the localization between Grid and Ground. The coordinates of the Occupation Point are calculated in the Grid and Ground coordinate systems.

  1. Import the set of points with coordinates in Ground coordinate system to the job. Then select the desired Grid projection.
  2. Perform the steps 2-6 in the previous scenario.
  3. Next measured pair of points is used in recalculation of the occupation point coordinates.

Results Screen

The dialog displays the data collected from the performed measurements:

If there is sufficient data to compute the resection, the results of resection are displayed: standard deviations for coordinates and calculated scale factor.

Note: Grayed Scale Factor indicates that this resection will not affect the scale factor currently used in job.

The following buttons are available:

If required, click to save the results to a file.


Pop-up menu

Additional options which can be useful are as follows:


Resection Options

The Resection Options dialog lets you select the resection type and method and the input parameters.

  1. From Resection Method define the required method, by selecting one of the following options from the drop-down list:
  2. Set the Scale Factor:
  3. If required, clear the Use Default Measurement Accuracy check box to change the system default values for measurement accuracy:

Benchmark

The Benchmark method allows you to determine the elevation of an occupation point using measurements to points with known elevations.

Benchmark: Define instrument setup

Set the occupied point:

  1. In Occupy, enter the name of the point for which the elevation will be computed. You can set the point in one of the following ways:

  2. Set Code for the point:
  3. Enter the height of the instrument ( HI) in the current units.
  4. From the drop-down list, select the Update method that will be used when saving Benchmark result:
  5. Click Next to continue in the Benchmark: Specify a control point dialog.

The icon brings up the pop-up menu of additional options. More...


Benchmark: Specify a control point

Take the measurements to known vertical locations:

  1. Enter the known vertical location in one of the following ways: click the switching button to choose either Point or Elevation.
  2. Enter the height of the reflector. Type the value manually or click the button with current reflector icon to select one of the previously used values from the context menu. If prism is used as a target you can also quickly review or change its configuration: select Edit from the context menu to open the Prisms dialog.
  3. Review current TS settings: measurement method, horizontal and vertical angles, slope distance. For more convenience, you can switch any time between Normal / Map / Results views by clicking on the title bar and using drop-down menu. Click / to take measurements. More... Then the dialog will switch to the Benchmark: Results.

Benchmark: Results

The dialog displays the data collected from the performed measurements:


Sd H value shows the following:

Use the context menu to manage the list of performed measurement sets:

Click the action buttons:

If required, click to save the results to a *.txt file.



Benchmark: Pop-up menu

Click to open the Benchmark dialog menu:



Reference Line Setup

The option allows you to calculate or recalculate the coordinate of the occupation point using a reference line with the known start and end points.

Set the occupation point:

  1. In Occupy, enter the name of the point where the instrument is set up. It can be either a new occupation name or a known point to recalculate. You can enter the point in one of the following ways:
  2. Enter the height of the instrument (HI) in the current units.
  3. Click Next to select a first design point. More...

The icon brings up the pop-up menu of additional options. More...


Reference Line Point

Select a start point for setting the reference line:

  1. Select a Point by typing its name, selecting it from the map or from the list .
  2. Note: If you have entered a new point name, the software will prompt you to manually enter this point coordinates in the Add Points dialog.

  3. Optionally, enter the offset values from the point in horizontal and vertical planes:
  4. The plot below will schematically show your selections.
  5. Click Next to take measurements. More...
  6. After saving the start point of the line (or the offset point) automatically the Reference Line Setup dialog is opened. Select the end point of the reference line (and offset from the point, if required) and click Next to take measurement. More...

Point Measurements

Setup the target point and sight to it:

  1. Enter the height of the reflector. Type the value manually or click the button with current reflector icon to select one of the previously used values from the context menu. If prism is used as a target you can also quickly review or change its configuration: select Edit from the context menu to open the Prisms dialog.
  2. Click to take measurements.
  3. Review the results of calculation after saving the measurement to the end point. More...

Reference Line Results

The dialog shows the setup information graphically. The instrument location is solved based on the measurements, the azimuth between the two points, and the hold location.

  1. Observe the reference error.
  2. Select which point should be held:
  3. Click Accept to store the new coordinates in the database.
  4. Click Back to return to the previous dialog.

If required, click to save the results into a *.txt file.


Reference Direction

The option allows you to calculate or recalculate the coordinate of the occupation point using a reference line with a known point and known azimuth.

Set the occupation point:

  1. In Occupy, enter the name of the point where the instrument is set up. It can be either a new occupation name or the known point to recalculate. You can enter the point in one of the following ways:
  2. Enter the height of the instrument (HI) in the current units.
  3. Click Next to select a known point. More...

The icon brings up the pop-up menu of additional options. More...


Reference Direction Point

Select a start point for setting the reference direction:

  1. Select a Point by typing its name, selecting it from the map or from the list .

    Note: If you have entered a new point name, the software will prompt you to manually enter this point coordinates in the Add Points dialog.

    Note: If the design point has no elevation (i.e., is a 2D point), the result point will have no elevation as well.

  2. The plot below will schematically show your selections.
  3. Click Next to take measurements. More...

Point Measurements

Setup a point on a reference line and sight to it:

  1. Enter the height of the reflector. Type the value manually or click the button with current reflector icon to select one of the previously used values from the context menu. If prism is used as a target you can also quickly review or change its configuration: select Edit from the context menu to open the Prisms dialog.
  2. Click to take measurements.
  3. Review the results of calculation after saving the measurement to the second point. More...

Reference Direction Azimuth

In this dialog you need:


Reference Direction Results

The dialog shows the setup information graphically. The instrument location is solved based on a reference line with known point and known azimuth and performed measurements. Click Accept to store the new instrument coordinates in the database.


Pop-up menu

Additional options which can be useful are as follows: