Coordinate System

To specify the Coordinate System for the Job:

  1. In Projection select the projection to be used from the drop-down list. Initially the list is empty. Click to open Pre Defined CS dialog and activate projections necessary for work.
  2. Select the Use Grid/Ground check box to enable transformation to ground coordinates for surveying. Click to open Grid/Ground Parameters dialog and set transformation parameters. Find out more on Grid to Ground transformation. After closing the Coordinate System dialog, the default display system will be Ground.
  3. In Datum specify the datum as required for the projection selected. Select the datum from the drop-down list.
  4. If NAD 27 datum is selected, you can use one of the following:

    If ATS77(CSRS), NAD 27(CSRS) or NAD 83(CSRS) datum is selected, you can use one of the following:

    Note: The NAD83 datum has three independent realizations in MAGNET Field with respect to the WGS84 datum: NAD83, NAD83(ITRF96) and NAD83_NO_TRANS. More...

    Click to add a custom datum if necessary. More...

  5. Select Geoid from the drop-down list. The job will refer to the selected geoid file to convert ellipsoidal heights to elevations. Click to add the geoid to the list. More...

Click to open the dialog menu with additional options:


Pre Defined CS

The Pre Defined CS dialog contains a list of cataloged projections divided by regions, that can be chosen for use in the job.

To add a desired projection to the list in the Coordinate System dialog:

In the Pre-Defined panel:

In the Active panel:


Custom Projections

Besides projections that are predefined in MAGNET Field, it is possible to use custom grid projections. Custom projections can be of the following types:


The Custom Projections dialog contains a list of custom (user-defined) projections. Projections obtained from the base station are marked with the icon in the list.


Custom Projection - 1

To create a new custom projection:

  1. Enter a Name for the new projection.
  2. Select a Type from the list of sample projections.
  3. Select a Datum from the displayed list of datums, or click to create a custom one (more...) and then select it.
  4. Enter the Region to which the projection belongs. If no region is specified, it will be added to the Global list.
  5. Enter a description (Note) for the projection.
  6. Click Next to enter the new projection specifications depending on the selected sample projection type. More...

Custom Projection - 2

Depending on the Type of projection selected, you are prompted to fill in some of the following fields.

  1. Enter the latitude (Lat0) and longitude (Lon0) of a point chosen as the origin on the central meridian of the custom projection.
  2. Enter the false Easting (East0 or E0) and Northing (North0 or N0) of the origin for the projection. These constant values are added to all negative Eastings and Northings to get only positive values of Easting and Northing.
  3. Enter the Scale that sets a constant scale factor along the central meridian of the custom projection.
  4. Enter the longitude of Central Meridian for the projection.
  5. Enter the North and South latitudes bounding the area of the custom projection (NorthLat and SouthLat).
  6. Enter the azimuth of the axis (AxisAzimuth) for the projection.
  7. Click to create the new projection and add it to the Projection list.

Note: The Latitudes are positive for the Northern Hemisphere, and negative for the Southern Hemisphere. The Longitudes are positive for Eastern directions and negative for Western directions relative to the GMT line.


Custom Datums

Besides datums that are predefined in MAGNET Field, it is possible to use the custom ones. Custom datums can be of the following types:


The Custom Datums dialog contains a list of custom (user-defined) datums. Datums obtained from the base station are marked with the icon in the list.


Custom Datum - 1

To create a new custom datum:

  1. Enter a Name for the new datum.
  2. Select an Ellipsoid from the displayed list of ellipsoids, or click to create a custom one (more...) and then select it.
  3. Select a coordinates transformation Method.
  4. Enter a description (Note) for the datum.
  5. Select an Alias for a new datum.
  6. Click Next to enter transformation parameters to convert from WGS84 to the new datum. More...

Custom Datum - 2

MAGNET Field uses the seven-parameters Helmert Transformation Strict Formula for datum transformation.

Note: If NTv2 method is selected in the Custom Datum - 1 dialog, this dialog allows the user to browse for the desired NTv2 *.gsb file for datum transformation and only displays NTv2 meta data for reference.

To create a custom datum:

  1. In Offsets, enter the Datum to Space (WGS84) offsets: dX, dY, dZ.
  2. In Rotations, enter the Datum to Space (WGS84) rotations: rX, rY, rZ, in seconds.
  3. In Pivot Pt, enter the coordinates of the pivot point X0, Y0, Z0 (available if Molodensky (with Pivot Point) method of coordinates transformation is selected in the Custom Datum - 1 dialog.
  4. Enter the Scale in parts per million (ppm).
  5. Select the Direction of coordinates transformation.
  6. Click to create the new datum and add it to the Datum list.

Custom Ellipsoids

This dialog contains a list of custom (user-defined) ellipsoids.


Custom Ellipsoid

To create a custom ellipsoid:

  1. Enter a Name for the ellipsoid.
  2. Change the values of ellipsoid semi-major equatorial axis (A) and inverse flattening (1/F) as required.

    Note: By default, the A and 1/F fields contains the values for the most common reference ellipsoid defined by WGS84.

  3. In Note, enter a description for the ellipsoid.
  4. Click to create the new ellipsoid and add it to the list of all the available Ellipsoids.

NTv2 Datum Direction / Advanced CSRS Options

In this dialog you can choose the transformation direction for the custom NTv2 Datum or transformation direction between ATS77(CSRS), NAD 27(CSRS) or NAD 83(CSRS) and NAD83_NO_TRANS datums.


Geoids List

Geoid is the physical reference surface of the Earth. Its shape reflects the distribution of mass inside the Earth. Geoid undulations are important for converting GPS-derived ellipsoidal height differences to orthometric height differences (elevations).
The Geoids List dialog contains a list of Geoids available for selection: the Name and Full Path and Type.


Add / Edit Geoid

In the Add / Edit Geoid dialog, select a Geoid file from disk and see the boundaries for the geoid. After being chosen, the geoid file appears in the Geoids List dialog.

To add a geoid to the geoids list:

  1. Select the Geoid Format of the geoid file to load.
  2. Click Browse to navigate to the desired file in the selected geoid format and select it.
  3. Click to add the selected geoid to the list of all the available Geoids in the jobs.

Geoids / Datums / Projections

This dialog contains a list of cataloged geoids, datums or projections available for download via the Internet for use in the MAGNET Field job.

To add a desired geoid / datum / projection to the current job:

In the Remote panel:

In the Download panel: