Reprojection and File Format Conversion in Global Mapper
Among the many advanced tools for data creation, editing, and analysis, Global Mapper also supports the basics of GIS: data reprojection and file format conversion. These topics may seem unimportant when compared with advanced workflows such as lidar classification and mesh creation. Still, the projection used to write and display data along with the file format used to store data is present in all geospatial workflows, making them necessary considerations when working with any data.
The projection of data used in geospatial workflows is vital for proper display, analysis, and sharing of data. Since the handling and conversion of projection are crucial in GIS work, reprojection of data for display and export has been made easy in Global Mapper.
In Global Mapper, the map projection is managed and changed through the Projection tab of the Configuration settings. The first file loaded into Global Mapper sets the projection for the workspace, but through the dedicated projection dialog, a new map projection can be selected, and when applied, the data display will update, reprojecting all loaded data on-the-fly.
A projection can be selected using the dropdown menus, a search by EPSG code, or by loading a projection from a file. Any data exported to formats that do not require the use of a specific projection will be created using the projection specified in the Global Mapper Configuration dialog.
If all work done in Global Mapper requires the same projection, a Default Projection can be set up through the Configuration dialog. Once enabled, the default projection will be used regardless of what data is loaded as the first file in a new workspace. The projection of data can still be changed through Configuration for data display or export, but the use of a default projection standardizes the projection automatically.
When working across different platforms and software programs, users need to ensure the file format they’re working with is supported within all applications in their workflow. Some programs have very limited format support, but thankfully, Global Mapper is not one of them. Supporting over 300 file formats for import and over 200 for export, Global Mapper is set up to provide the very necessary function of file format conversion.
To convert a single file, first load it into a Global Mapper workspace, and then export the data to the desired format. Within the workspace, before export, data can be edited, analyzed, and reprojected as needed. An export from Global Mapper is initiated from the File menu or with a right-click on a specific layer in the control center. Based on the data type being exported, appropriate file formats for raster, vector, or elevation data will be available for selection. A format-specific export options dialog allows the fine-tuning of the export to a new file.
Uniting reprojection and file format conversion together in Global Mapper is the Batch Convert/Reproject tool. This tool provides the ability to convert formats and reproject multiple data files without needing to render them in the 2D map view of Global Mapper.
With options to load individual files or all the files in a directory, the Batch Convert/Reproject tool allows the user to select the input and output format, and reproject many data files to the same selected projection.
If you enjoyed this blog, you may also find this resource useful: https://www.youtube.com/watch?v=4jlI_ruGBmE&t=13s