Geo Suite – Calculator

Geo Suite – Calculator

Geo Suite Calc flash screen

The tool

  • Provides a simple but elegant classical geodetic calculator designed to provide:
  • Coordinate operations of type:  Conversion and transformation between two user-selected coordinate reference systems
  • Perform distance and azimuth computations between pairs of points (known as forward and reverse computations)
  • Provide file conversions with user defined file format specifications
  • Full compliance with EPSG database and ISO terminology
Calc front page
Geo Suite Calc – Benefits
  • Simple user interface
  • Direct link to Geo Suite Catalogue (EPSG geodetic parameter registry) for geodetic parameter definition
  • User-defined file format function provided
  • Inventory of pre-defined file formats provided, e.g. UKOOA P1, SEG-P1, SPS etc.
  • Coordinate Operations of type:  Conversion and Transformation algorithms comply to EPSG guidance notes 373-07-2
  • Reverse and forward computations provided
  • Single point-to-point and file to file coordinate operations provided
  • Fully GIGS tested.


CRS Parameter selection

Prior to computations being performed the geodetic parameters for both Point A (source) and Point B (target) coordinate reference systems must be supplied.  This can be done in one of two ways:

1. From within Geo Suite Catalogue module.  If user is viewing CRS definitions within Geo Suite Catalogue then Geo Suite Calculator can be spawned at directly populated with the CRS parameters being viewed.

viewing CRS parameters

2.  Source and Target CRS can be selected from the ‘CRS definition wizard’ provided within Geo Suite Calculator. Details of this are shown thus:

The wizard provides a set of filters to list only the CRS’ that fit that criteria from Geo Suite Catalogue. Filters are based on geographical area and coordinate reference system type (Geocentric, 2D Geographic, 3D Geographic and Projected).

Source CRS selection

Vertical datums are also recognized to enable gravity-related vertical components to be selected to create compound CRS definitions.

Vertical CRS selection


Single Point Conversions

Once Source and Target CRS’ have been selected the main panel of the Calculator will display the selections made along with the basic parameters associated with each CRS.  Geo Suite Calculator can now perform computations between the CRS’s selected.

The default computation is that of a single point coordinate operation whereby the coordinates of a point are entered into either Point A or Point B and the coordinate operation (either conversion or transformation) is performed between the two by clicking on the required arrow button in the middle column.

CRS definition panel

File Conversions

A file containing multiple points (of the same format and CRS definition) can also be operated upon between the source and target CRS’s selected.  An ‘import wizard’ is provided so user can provide the format of the input file and thus does not restrict the user from pre-conditoning the file prior to use.   The wizard guides the user through a series of steps required to define the location of the coordinates contained within the file (e.g. row and column definition).  An inventory of common exchange file formats are also recognized in addition to well known text and .prj files.

Text wizard wells

The converted data is exported to a user selected file.  The coordinates can be either appended to the original import file or written to a new file.  Details of the coordinates being exported are displayed within the main panel of the ‘Process File’ user panel.


Reverse and forward computations

The reverse and forward computation modes enable computations to be performed to compute distance, angular and coordinates between pairs of positions.   The relationship is shown below and comprises seven parameters, namely:  Two angular (forward bearing and reverse bearing), four positional (two coordinates for point A and two coordinates for point B) and one distance (s – geodetic or plane distance between point A and point B).

Reverse Computation

The reverse computation enables the distance and bearings (forward and reverse) to be computed between pairs of points when the coordinates of the two points is provided.    The coordinates of point A and point B will be submitted to the boxes provided and Geo Suite Calculator will determine the three unknown parameters. The answers are displayed in the box provided.

Computations can be performed on either an ellipsoidal surface or a plane surface depending of whether geographic or projected coordinates are used.  It is recommended that the computations are performed on the ellipsoidal surface to preserve accuracy.


Forward computations

The forward computation enables the coordinates of point B to be computed when the coordinates of point A are known along with the distance and bearing to point B.  The reverse bearing from point B back to point A is also determined as part of the computation.

The coordinates of point A are entered into the fields provided.  The Forward button is selected and a secondary panel will appear requiring entry of the distance and bearing to point B.  Once provided the coordinates of point B along with the reverse bearing will be determined.


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