GeoDLL - Geodetic Development Kit
Development Tool for coordinate transformation and GIS

•  Detailed Description of the current Version
•  Descriptions of the GeoDLL Function Groups
•  User Manual with all Function Descriptions
•  User Manual searching for expressions
•  List of Coordinate and Reference Systems
•  Download of the supported NTv2 / HARN grid files
•  Programming example  Group Prices GeoDLL
•  Download  Place order

GeoDLL is a Geodetic Development Kit or a Geodetic Function Library for worldwide 2D and 3D Coordinate Transformations and Datum Shifts with highest accuracy and for calculating Meridian Convergence and many Extra Parameters. Furthermore: Helmert and Molodensky Parameters, NTv2, HARN, INSPIRE, EPSG, Digital Elevation Model (DEM), distance and Time Zone calculations and much more. GeoDLL is available as 32Bit and 64Bit DLL and as C++ source code.

GeoDLL - Version 24.37 - Last update on 30 July 2024
The latest larger changes  History of Modifications and Supplements

1. New WGS84 reference systems ITRF2020 (G2139) and ITRF2024 (G2296).
2. Calculations from/to WGS84 with more accurate ITRF2014 realization.
3. New ITRS epochs 2024 to 2026 for North America, Australia and Europe.
4. Coordinate and reference systems adapted to EPSG version 10.091.
5. NTv2 reference systems updated for the German Federal State Hamburg.

Geodetic Development Kit

Detail of the GeoDLL header file

Detail header file

Detail of the sample program

Detail sample program

Detail of a function description

Detail function description

The Geodetic Development Kit GeoDLL is an easy to use function library which is designed particular for GIS professionals and software developers. GeoDLL allows developers to embed thousands of preadjusted, precise coordinate transformations and geodetic datum shifts and custom best fit transformation parameters into their individual geoinformatics software. GeoDLL supports datum shifts with Seven Helmert Parameters and Three Molodensky Parameters and with NTv2 and HARN grid shifts. GeoDLL contains many geomatics tools for GIS development, such as creating Helmert and Molodensky parameters parameters and NTv2 grid files, tools for analyzing and manipulating NTv2 files, INSPIRE and EPSG support, digital elevation models, distance calculations and time zone determinations. GeoDLL has grown with many improvements over the years and it continuously benefits from user feedback. Thanks to the numerous improvement suggestions of the users the quality and the scope of functions of the Geodetic Development Kit increase constantly.

GeoDLL - Detailed Description of the Geodetic Development Kit
Development of your own Geodetic Software

GeoDLL supports the development of geodetic software on various platforms by providing geodetic functions. The operating system WINDOWS provides software developers the opportunity to use prepared functions of third-parties in their own software applications. Thus, geodetic functions of GeoDLL can be linked to programs written in C, C++, C#, Java, Pascal, Delphi, MS-Access, Visual Basic, Visual Objects or which are written in other programming languages. To support the GeoDLL, examples and interfaces with source code for many commonly used programming languages are provided.

GeoDLL comes with extensive documentation and is supplied as DLL file for 32bit and 64bit architectures or as C / C++ source code. GeoDLL works with most programming languages and it can be used with Microsoft Office programs. GeoDLL is written in C / C ++ and is developed using Microsoft Visual Studio. Thus very fast performance, compact code and high stability are assured. The functions of GeoDLL are prepared for multithreading.

Main Task: Coordinate Transformations

The most important application of GeoDLL is to include professional Coordinate Transformations in own programs. These Coordinate and Reference Systems are supported:

1. The current and historical Systems of all countries of Europe
2. The European ETRS89 systems forced by INSPIRE
3. The US and Canadian NAD, NTv2, HARN and SPCS Coordinate Reference Systems
4. The Coordinate Reference Systems of most countries of all continents
5. The Coordinate Reference Systems of Germany, Austria and Switzerland incl. NTv2
6. The Geographic coordinates in different notations and Cartesian coordinates
7. Worldwide NTv2 grid file supported Coordinate Transformations
8. Worldwide used numeric and alphanumeric Coordinate Systems
9. Most of EPSG supported Coordinate Reference Systems
10. ITRS annual realizations or WGS84 epochs for GPS measurements
11. WGS84 Coordinate Transformations in consideration of the continental drift
12. User defined Coordinate Systems, Reference Systems and earth ellipsoids
13. Meridian Convergence, Origin Center Meridian, Geographical Point Coordinates

In some countries, here  Germany as an example, the there available Coordinate Reference System are broken down in more groups:

1. The Coordinate Reference Systems of the old and new German Federal States
2. The German 'Lagestatus' Coordinate Reference Systems
3. The high-precision Reference Systems of the German Federal States incl NTv2
4. The 40 Soldner Coordinate Systems of the Prussian Land Registers

You find a  complete list of the supported Coordinate and Reference Systems on our internet site and after downloading (see above) the free test version as part of the documentation.

Coordinate Transformation Scheme

Calculation accuracy

GeoDLL uses Coordinate Transformation formulas based upon EPSG specifications and publications by Schatz, Schuhr and Klotz and Hooijberg. Algorithms used for country-specific transformations are either published or made directly available by the Measurement Authorities of the respective countries or by similar respectable institutions. To achieve the highest precision only strong formula algorithms are used for calculations.

Coordinate Transformations without changing the geodetic Reference System have extremely high precision ranging within millimeters. A good example of geographic coordinates transformations between Gauß-Kruger and UTM Coordinate Systems made with GeoDLL are the results published by the North-Rhine Westphalia Land Survey Commission. It was confirmed that the differences were within the lower millimeter range.

For a statement about the accuracy were comparative calculations realized with a set of test data of the "Arbeitsgemeinschaft der Vermessungsverwaltungen der Länder der Bundesrepublik Deutschland" (ADV). It was confirmed that the differences were less then 0,2 millimeter. Please read the  test report.

Another interesting test series for a quality check was conducted by the German network operator Westnetz GmbH with an extreme NTv2 file. More than 4.3 million points were transformed with TRANSDATpro / GeoDLL and with a reference software from Gauß-Krüger/DHDN90 to UTM/ETRS89 and then compared. There were only very rarely deviations of more than one millimeter. These only affected coordinates that were outside the scope of the NTv2 file. The test result and statements on the calculation speed can be found in our  publication.

Performance

GeoDLL is written in the programming language C++ and developed on Microsoft Visual Studio. This results in extremely fast execution, compact code and high running stability. The functions of GeoDLL are multithreading ready and so it supports Multi Core processors.

Function groups

The geodetic functions of the GeoDLL are encapsulated for specific tasks in function groups, which can be separately licensed and purchased. On  this web page all function groups are listed for selection as further links.

Function descriptions

You can view the detailed descriptions of all GeoDLL functions in the  Online User Manual. Detailed description of all geodetic functions in an English and German language MS-help documentation and a runnable test version of GeoDLL are contained in the  download file.

Scope of services of the function groups

The characteristics of the various functional groups and the contained functions are listed under further links at the top of this site.

1. Source and target Coordinate Reference Systems
2. Worldwide and country-specific Coordinate Reference Systems
3. Current and historical Coordinate Reference Systems
4. Numeric and alphanumeric Coordinate Systemsv
5. UTMRef, GEOREF, QTH, BNG, NAC und ING with different grid mesh sizes
6. Plus Code, Google World / Pixel / Tile coordinates with different grid sizes
7. INSPIRE systems, ITRS annual realizations, WGS84 epochs, GPS coordinates
8. 2D and 3D Coordinate Transformations
9. Use of EPSG codes of the Coordinate Reference Systems
10. Selection of the meridian strip with UTM and Gauss-Krueger coordinates
11. UTM and Gauss-Krueger coordinates with and without meridian strip number
12. Calculation of Meridian Convergence, Origin Center Meridian, Geographical Point
13. Use of measurement units
14. Monitoring of range limits
15. Option for the automatic assignment of a Reference System to the Coordinate System
16. Calculation of Helmert and Molodensky Parameter Sets from identical points

1. Quality
2. Strict formulas of Schatz, Schuhr, Klotz and Hooijberg
3. Transformation parameters of the Surveying Authorities of the respective countries
4. Consideration of the EPSG specifications
5. Helmert Seven Parameter Bursa-Wolf and Molodensky Reference System Transitions
6. Exact NTv2 transformations for many countries
7. High-precision NTv2 transformations for the German Federal States

1. Special features
2. 32bit and 64bit architecture
3. Network capability
4. Multithreading capability
5. Server capacity
6. CITRIX support
7. EventLog handling

1. Help System
2. Detailed electronic manual
3. Uniformly geodetic terms in all text outputs and in the electronic manual
4. Explanation of geodetic terms in the glossary
5. Online FAQ section for common questions
6. Detailed list with predefined Coordinate Reference Systems
7. Coordinate Systems and Reference Systems in the list have numerical GeoDLL keys
8. Hierarchical structure of the list by continent, country, Coordinate System, Reference System
9. Additional alphabetic list

1. Multilingualism
2. Text outputs in English and German
3. User manual in English and German

1. Application Program Interfaces and Sample Programs
2. Sample of a C++ interface
3. Sample of a Visual Basic interface
4. Sample of a Delphi interface
5. Sample of a Visual Objects interface
6. Sample of a C# interface (NET Framework)
7. Sample program in C++
8. Sample program in Visual Objects
9. Sample of a function call in C++ syntax
10. Sample of a function call in Visual Basic syntax

1. More possibilities
2. Possibility to download NTv2 files from the KilletSoft website
3. Configuration of user defined Coordinate Systems
4. Configuration of user defined Reference Systems and ellipsoids
5. Possibility of a service contract for phone and E-Mail support
6. Possibility to use the automated newsletter service via E-Mail
7. Transfer of transformation parameter sets from the SEVENPAR program
8. Support of Polygonal Validity Scopes in NTv2 files from the NTv2Poly program
9. NTv2 tools for analyzing and manipulating of NTv2 files

Dynamic Link Library (DLL)

The operating system WINDOWS provides software developers the opportunity to use prepared functions of third-parties in their own software applications. Thus, geodetic functions of GeoDLL can be linked to programs written in C, C++, C#, Java, Delphi, MS-Access, Visual Basic, Visual Objects or which are written in other programming languages. To support the GeoDLL, examples and interfaces with source code for many commonly used programming languages are provided. An example of using GeoDLL is the program  TRANSDATpro that is available for download on the internet.

Memory model

GeoDLL is delivered for WINDOWS operating systems with 32bit and 64bit architecture. Therefore, the DLL can be used with win32 applications on 32bit and 64bit WINDOWS operating systems and with x64 applications on 64bit WINDOWS operating systems.

C++ Source Code

It is frequently asked whether the geodetic functions are also available for other operating systems such as LINUX or UNIX. Also some developers would not like to build in geodetic solutions without knowledge of the source code into their programs. For these reasons, the complete GeoDLL can also be purchased as C++ source code.
The source is extensively written in ANSI-C++, so that the migration to other operating systems and hardware platforms is possible with manageable effort. GeoDLL has been developed with Microsoft Visual Studio under the operating system WINDOWS.
All source codes of GeoDLL are directly compilable and executable under WINDOWS with Microsoft Visual Studio, Versions 10 to 15. For the conversion to other platforms or other development environments adjustments in the source code may be necessary.

Coordinate and Reference Systems

All the  Coordinate and Reference Systems, supported by GeoDLL, sorted on continents and countries with additional information are put together on a separate internet page.

NTv2 support

Exact datum shifts in local systems are possible by supporting the  NTv2 standard with grid files.

Digital Elevation Models

GeoDLL supports the Digital Elevation Models CGIAR and GLOBE (3 and 30 second rasters) for the point-exact determination of ground elevations over the Mean Sea level. Detailed information about the use of the  Digital Elevation Models are arranged on a separate internet page.

Definition files, Interface sources, Example sources

GeoDLL already contains some ready to use interfaces and definition files for integration of geodetic functions into the programming language of your choice. Also some example sources in different programming languages are present. The source codes listed here are provided in the download file.

1. Linkable import library file for the programming languages C / C++ in 32bit architecture
2. Linkable definition file for the programming languages C / C++ in 32bit architecture
3. Linkable function declarations for the programming languages C / C++ in 32bit architecture
4. Linkable import library file for the programming languages C / C++ in 64bit architecture
5. Linkable definition file for the programming languages C / C++ in 64bit architecture
6. Linkable function declarations for the programming languages C / C++ in 64bit architecture
7. Linkable import library file for the programming language Visual Objects
8. Template of C/C++ 32Bit Visual Studio Project ( download)
9. Template of C/C++ 64Bit Visual Studio Project ( download)
10. Template of C# Visual Studio Project ( download)
11. Example of C++ interface
12. Example of Visual Basic interface
13. Example of Delphi interface
14. Example of Visual Objects interface
15. Example of C#-interface (NET Framework)
16. Sample program in C++
17. Sample program in Visual Objects
18. Sample program in Python

Test version / Full version

GeoDLL is available for download from this site as a test version (shareware). All DLL functions can be used without restrictions for a limited period of time. That is enough for testing and determining whether the GeoDLL functions run with your application. You can lift time limitations by entering the unlock codes you can obtain from KilletSoft GbR for each of the above listed function groups. The unlock codes are passed to the DLL-function setunlockcode(<unlock key>,<user ID>) from your application. Then all subsequent calls to the functions of the unlocked group will have no more time limitations.

License models

The  license models described here require only a unique payment. No additional payments are raised as a function of the number of customer installations or on the service life of the license. The unlock code provides you with the right of using the functions of the unlocked group. Several licensing models are available:

1. Single license: A Single function group license entitles the license holder to use the functions of a Geodetic Function Group with a single software application developed by the license holder. Applications developed by the license holder using the geodetic functions of a group, can be distributed to any number of customers or can be installed as a single application on the Internet server of the license holder, or the server of the license holder's Internet service provider.
2. General license: A General function group license entitles the license holder to use the functions or a Geodetic Function Group with any number of applications developed by the license holder. Applications developed by the license holder using the geodetic functions of a group can be distributed to any number of customers and can be installed on multiple Internet servers of the license holder or the license holder's Internet service provider.
3. Internal license: An Internal License entitles the licensee to use the functions or a Geodetic Function Group with any number of applications developed by the licensee. Applications developed by the licensee using the geodetic functions of a group may not be distributed to customers and may not be installed on an Internet server. Applications created with this license must be in context with tasks of research and education.

Pricing and ordering

Available selective licensing of several function groups guaranties that you only pay for those functions that you intend to use. Pricing and ordering information can be found in the  Price list. Order the for GeoDLL function groups with the electronic  Order Form.

Download of the test version

The test version of the Dynamic Link Library GeoDLL with a detailed description and with information about the use of the functions can be  downloaded as ZIP packed file by the Internet.

Use of an illegal Geodetic Development Kit

Managing Director Fred Killet explains why you should never use an  illegal version of our Geodetic Development Kit GeoDLL.