Coordinate System Conversion in Micromine Origin&Beyond
In general, coordinate systems can be global, which cover the entire Earth, regional, which are used for specific regions, and local (conditional), which are created for local sites. For Ukraine, the most common modern global coordinate system used for geological data is UTM (WGS 84) – Universal Transverse Mercator (World Geodetic System 1984). Regional systems include CS-42 (Gauss-Kruger), which often presents historical data, and UCS-2000 (formerly CS-63), the State Geodetic Coordinate System of Ukraine, which is used for topographic and geodetic data and cartographic data.
Geologists often face a situation where data with different coordinate systems are used for the same project. For example, historical exploration data are often presented in a local coordinate system, regional historical data in CS -42, surface topographic surveys in UCS-2000, and external global data (satellite images, etc.) in UTM (WGS 84). Also, often different specialists (geologists, surveyors, mining engineers) working on the same project have their own “favourite” coordinate systems that they use.
The correct conversion of coordinates between systems is crucial to ensure that all project data is correctly aligned. Otherwise, errors can negate the results of modelling, design and other activities and at last lead to time and money lost.
If you use GIS to create a project, you need to specify a coordinate system. In this case, all information about coordinate systems and projections is stored in a special file (for example, a *.prj file). Micromine Origin&Beyond does not require setting up a coordinate system to create a project and treats coordinates as raw numbers. Micromine “trusts” the user, assuming that they are confident in the project coordinate system, and does not need a built-in file to store all coordinate systems.
Micromine Origin&Beyond offers easy conversion between coordinate systems using special functionality. All coordinate conversion functions are included in the Core module and are available to any user, regardless of the Micromine bundle used.
1. Basic Coordinate Conversion Functions
2. Micromine Origin & Beyond Coordinate System Types
Micromine Origin&Beyond works with three main coordinate types: EPSG, local, and advanced.
Coordinate systems from the EPGS database. To apply standard coordinate systems, Micromine Origin&Beyond uses the EPSG (European Petroleum Survey Group) database, which provides you with access to more than 5000 coordinate systems. The dynamic search function makes it easy to find the relevant system by part of the name or identification code. A world map shows the bounds of the selected coordinate reference system and allows zooming the map to see more details. Information about the selected reference system is shown below the list.
The Local Coordinate System use flat grids with rectangular X, Y, and optionally Z, coordinate, which are typical for for project areas a few tens of kilometres in size and is common for mining projects. To define a local coordinate system you must provide a pair of tie points whose coordinates you also know in another standard coordinate system (such as UTM). The further apart these tie points the more accurate the resulting transformation. At the bottom of the form show the difference in north direction and zoom between the two systems, which can be used for verification. The local coordinate system settings can be saved (Save As) and used for further transformations.
Advanced coordinate systems allow you to build a coordinate system by manually specifying individual parameters and their values, and are used to reconstructing an old (historical) coordinate system a custom one. To learn more about creating an advanced coordinate system, visit the Micromine Origin&Beyond Coordinate System Resources page.
So, to set up the coordinate system conversion, two reference coordinate systems (source and result) must be specified. Additional options provide a reverse conversion, a change of conversion method for standard systems, and a test with reference points.
The coordinate system conversion parameters can be saved (Save As) and used for coordinate conversions. The figure shows an example of converting the coordinates of drill holes and the licence boundary from the Pulkovo 42/Gauss-Kruger system (zone 6) to WGS 84/UTM (zone 36).
3. Keyboard, File and Wireframe Coordinate Conversion
Convert (Keyboard) coordinate function allows you to convert a single coordinate by entering values manually. This requires:
- • select an available Coordinate System Conversion (alternatively create one),
- • choose geographic coordinate units (for geographic systems),
- • enter the X, Y and, optionally, Z coordinate values.
To convert coordinates in a file, Micromine Origin & Beyond supports the following file formats:
This Conversation requires:
- • select an available Coordinate System Conversion (alternatively, create one),
- • specify geographic coordinate units (for geographic systems),
- • choose the input file and the relevant X, Y and, optionally, Z coordinate fields,
- • enable the option to use the source file to record the results and specify the coordinate fields, alternatively, the fields will be created automatically.
To convert coordinates in a wireframe, you need to specify the same parameters, but the type and name of the wireframe should be used as the input and output data.
4. Plane Grid Coordinate Conversation
The coordinate grid conversion parameters are determined based on the coordinates of two sets of 3D points. The Least Squares method is used to determine the optimal rotation and shift between the two sets of points. A Least-Squares method is used to find the optimal rotation and shift between the two sets of points.
You can specify any number of points (but not less than three) to calculate the least-squares error, which is displayed in the right-most column on each row. Use the checkboxes to exclude one or more points from the transformation.
Pick Point icons in each row of the Common Points grid, allow you to interactively pick the common points for coordinate systems A and B. Clicking on a Pick Point icon will collapse the dialog and allows you to select a point whose coordinates will be automatically loaded into the table. You can also select multiple points at the same time (by holding down the left mouse button or the SHIFT key). For the selected points, the centroid coordinates are calculated and loaded into the table.
The Conversion Parameters section displays the calculated parameters. In the corresponding fields, you can optionally enter the rotation values, scale and Z offset, to be used instead of the calculated value.
The Convert File and Convert Wireframe tabs set the conversion parameters for files and wireframes, as discussed above.
Plan Grid Coordinate Conversation is commonly used for the processing of underground laser scanning data and open pit surveys using unmanned aerial vehicles. Such data has an independent origin coordinate point and several points with scan coordinates and target system coordinates.
5. Coordinate Сonversion for File Import/Export and Raster Image Georeferencing
Micromine Origin&Beyond provides coordinate conversion options directly during the import or export of vector and other data, and during the image georeferencing. Directly in the dialogue in the coordinate systems section:
- • If you do not want to convert coordinates, select None,
- • Target EPSG option is only enabled if the Input file contains recognisable information about coordinate system. In this case, the coordinates are converted to the coordinate system defined by the Target EPSG,
- • Select the Conversion option to select or create a new coordinate conversion form set to convert between coordinate systems.
6. Display multiple coordinate grids
Micromine allows to display multiple coordinate grids as needed. To set up the display of multiple grids, in Vizex / Grid Settings, in the Configuration tab of the dialogue box, check the Additional Grids checkbox and fill out the corresponding form. The correspondence is based on 2 points with known coordinates in 2 systems.
Micromine Origin & Beyond provides functionality for conversion of coordinates:
- • single points entered from the keyboard,
- • files and wireframes using defined parameters or plane grids,
- • vector and other data for import or export,
- • georeferencing of raster and other images.
Such conversions are commonly used for operations on exploration and mining projects. Use convenient and user-friendly tools to quickly complete heavy and complicated coordinate system conversion calculations on your project.