December 28, 2021

GeoCalc Online: Using the New Point-to-Point Converter

Written by: Jeff Hatzel


What is GeoCalc Online?

GeoCalc Online is Blue Marble Geographics’ online geodetic parameter repository. It contains all coordinate systems, transformations, and other definitions used by Blue Marble’s software. It is directly utilized by several Blue Marble software products: Geographic Calculator, the GeoCalc SDK, and Global Mapper. Users of these applications are able to query and update any supported definitions, as GeoCalc Online is kept current with the International Association of Oil and Gas Providers’ EPSG Geomatic Registry.

Users visiting GeoCalc Online have the ability to search the repository using the Filtered Search tool with advanced filtering options or by utilizing the Map Search tool, bringing all geodetic definitions to their fingertips. Logging into the site with a Blue Marble account will give access to a variety of actions, such as viewing or printing a definition’s parameters. For a limited time, signing in with an account tied to a Geographic Calculator order, will also provide full access to the brand new Point-to-Point Converter.

Full mobile browser support now expands GeoCalc Online’s functionality even further. Users are not limited to running geodetic operations at their desks and can now work anywhere, searching the registry or logging in to run calculations in the field on the mobile device of their choice.

Point-to-Point Converter

Users of Geographic Calculator will find the Point-to-Point Converter similar to the popular Interactive Conversion Job found in the desktop software. The Point-to-Point Converter offers three operations: Convert, Forward, and Inverse. This blog explores the process of setting up a Convert operation in detail below. A Forward operation is used to compute a new coordinate that is a given distance and azimuth away from a starting coordinate. Similarly, an Inverse operation calculates the distance between two known coordinates on the same datum.

The Point-to-Point Calculator will have a familiar layout and functionality to Geographic Calculator’s Interactive Job.

When setting up a Convert operation, we’ll need to specify information regarding the source point and coordinate system, the target coordinate system, and the appropriate transformation between the two. GeoCalc Online provides users with a few different ways of completing this task. Those familiar with Geographic Calculator will find the Convert setup familiar. The point is entered, given a name, and a picker is used to select the source coordinate system.

While the picker can be used to set the target coordinate system as well, there may be times when searching for a system is more appropriate. Navigating to the Search page of GeoCalc Online allows a search to be conducted based on a map location or by using the Filtered Search on the left for more detailed search options.

In this example, EPSG Code 4326 was used as the search parameter for the Filtered Search. When viewing the search results, there are a variety of Actions that can be conducted; in this case, I chose Set As Converter Target. It’s worth noting that either the Source Point Coordinate System and/or the Target Point Coordinate System can be set via this method, or from the aforementioned picker.

Viewing Actions associated with a search result allows users to directly set that coordinate system as the source or target in the Point-to-Point Calculator. Other Actions provide ways to view and share a given definition.

After navigating to the Point-to-Point Calculator, we’ll see the coordinate system that was previously set has been applied as the Target Point Coordinate System. Choosing “Select Transformation” will open the transformation picker. Finding and selecting a transformation involves a similar process to setting the Source Point Coordinate System. Once the operation is fully set, clicking “Calculate” will process the calculation, with alert messages displayed below.

The banner across the bottom will alert users of any issues with their calculations. In this case, it was a success.

Without any need to install software, GeoCalc Online’s Point-to-Point Converter allows users to conduct basic operations right in the web app, expanding the reach of GeoCalc to users in the field.

Take a moment to check out GeoCalc Online! If you don’t have a Blue Marble account and would like to get a full trial of the Point-to-Point Calculator, please contact

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