Description of the DLL

 

 

GeoDLL supports the development of geodetic software on various platforms by providing geodetic functions. GeoDLL contains  precise calculations on the themes 2D and 3D Coordinate Transformation, Reference System Transitions, meridian strip changing, user defined Coordinate Reference Systems, distance calculations, Digital Elevation Model, NTv2 and HARN support, Analyzing and manipulation of NTv2 files, Polygonal Validity Scopes, Direct / Inverse solutions, map function, Time Zone calculations and geodetic converting functions with high precision and high performance.

 

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

 

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, CA-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.

 

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

The current and historical Systems of all countries of the European Union (EU)
The coordinate reference systems of the European non-EU countries
The European ETRS89 systems forced by INSPIRE
The US and Canadian NAD, NTv2, HARN and SPCS Coordinate Reference Systems
The Coordinate Reference Systems of most countries of all continents
The Coordinate Reference Systems of Austria and Switzerland incl. NTv2
The Coordinate Reference Systems of the old and new German Federal States
The German 'Lagestatus' Coordinate Reference Systems
The high-precision Reference Systems of the German Federal States incl. NTv2
The 40 Soldner Coordinate Systems of the Prussian Land Registers
The Geographic coordinates in different notations and Cartesian coordinates
Worldwide NTv2 grid file supported Coordinate Transformations
Worldwide used numeric and alphanumeric Coordinate Systems
ITRS annual realizations or WGS84 epochs for GPS measurements
WGS84 Coordinate Transformations in consideration of the continental drift
User defined Coordinate Systems, Reference Systems and earth ellipsoids
Meridian Convergence, Origin Center Meridian, Geographical Point Coordinates
Calculation of more extra parameters
Coordinate System range validity check

 

 

Coordinate Transformation with Reference System Transition

 

A detailed list of the supported Coordinate Systems, Reference Systems and Coordinate Reference Systems you can find in the chapter "List with Coordinate Reference Systems". User Coordinate Systems, local Reference Systems and earth ellipsoids can be defined, based on the Coordinate System parameters, the semi axes of the earth and seven Helmert or three Molodensky parameters.

 

GeoDLL supports the use of NTv2 grid files for Reference System Transitions. A detailed description of the NTv2 standard and information for free downloading of the NTv2 files from the Internet you find in the chapter "Information about the supported NTv2 grid files".

 

Detailed descriptions of the Digital Elevation Models and information for free downloading of the elevation data from the Internet you find in the chapter "Information about the used Digital Elevation Models".

 

 

Functionalities of the DLL

The DLL (Dynamic Link Library) GeoDLL contains functions for the execution of different geodetic calculations. All calculations are carried out with high exactness and height speed. Input errors and area injuries during the program run can be questioned with help of the error management of the GeoDLL and they can be evaluated by the calling program.

 

The geodetic functions of the DLL are put together in functional groups. The individual functions of the function groups are listed in the Table of contents.

1.The group "Coordinate Transformations" contains functions for the realization of 2D and 3D Coordinate Transformations with or without Reference System Transition.
2.The group "NTv2 Transformations" contains features for the use of NTv2 grid files for Reference System Transitions. The use of this group requires the unlocked function group "Coordinate Transformations".
3.Die group "NTv2 Tools" contains functions for manipulating and retrieving information from NTv2 grid files in ASCII and binary formats.
4.The group "User Definitions" contains functions for input of self defined Coordinate Systems, geodetic Reference Systems and earth ellipsoids which can be used with the functions of the group "Coordinate Transformations" besides the systems predefined in the GeoDLL.
5.The group "Parameter Determination" contains functions to return values of in GeoDLL predefined and user-defined Coordinate Systems, geodetic Reference Systems and ellipsoids.
6.The group "Distance Calculations" contains functions for determination of distance between two coordinates.
7.The group "Notation Calculations" contains functions for conversion of geographic coordinates of one notation in another and for correct decimal rounding of geographic coordinates of different notations.
8.The group "Map Calculations" contains functions for converting coordinates in TK-numbers of the topographic maps of Germany and to determine the corner coordinates of the topographic maps.
9.The group "Elevation Calculations" contains functions for the determination of ground elevations over the Mean Sea Level from digital elevation models.
10.The group "Transformation Parameter" contains functions to calculate Seven Helmert Parameter sets and Three Molodensky Parameter  sets from identical points in different Coordinate Reference Systems.
11.The group "Time Zone Calculations" contains functions to calculate time zones, UTC, DST, daylight change dates and other time zone parameters from coordinates or from listed time zone indexes.
12.All other functions don't belong to any group and don't require an unlock key.

 

Except of the last group, the other function groups must be unlocked for unlimited use with an unlock key purchased from the software distribution company. See: Test version and Full version

 

The function names contained in the DLL are filed in lower case letters. Please use for the definition of the function names lower case letters with computer languages which can differentiate between upper and lower case writing!

 

 

Memory model

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

 

To be able to use functions of the GeoDLL in your application, the files geodll32.dll or geodll64.dll and geodllbn.bin must exist in the start directory of your application. Alternatively, the file geodllbn.bin can be stored in a directory set to the function setdllworkdir. geodll32.dll and geodll64.dll contain the workable code of the geodetic functions. geodllbn.bin includes the constants of the GeoDLL supported Coordinate Reference Systems.

 

 

Performance speed

GeoDLL is written in the programming language C / C++ and developed on Microsoft Visual Studio 2010 and on Visual Studio 2015. Thus very fast performance, compact code and high running stability are assured. The functions of GeoDLL are multithreading ready and so it supports Multi Core processors. An example from a customer's environment demonstrates the power of GeoDLL.

 

 

Programming languages

GeoDLL was tested with C, C++, C#, Java, Pascal, Visual Basic, CA-Visual-Objects and Delphi, just to name some programming languages and it can be used with Microsoft Office programs like MS-Access. It is useable generally under WINDOWS with all programming languages which can generate 32bit or 64bit code and which can support the DLL concept or access the functions of the WINDOWS-API.

 

Please inform the program author of your experiences while testing the DLL with the programming language of your use.

 

 

Operating systems

For applications which were programmed under use of the GeoDLL , Microsoft WINDOWS 2000 / NT / XP / Vista / 7 / 8 / 10 / 11 and all compatibles are useable as operating systems. Thereby 32bit and 64bit architectures are supported.

 

GeoDLL complies with the compatibility standards of the Microsoft operating systems WINDOWS 7 / 8 and WINDOWS Vista. On the basis of the verified compatibility with the respectively latest WINDOWS operating systems, we can offer our customers increased security, innovative user interfaces and high reliability of our software.

 

 

C++ Source Code

Frequently we got inquiries whether the geodetic functions are also available for other operating systems like LINUX or UNIX. Also some developers would not like to build functionality without knowledge of the source code into their programs. For this reasons we decided to offer the geodetic functions as source code. The source is extensively written in ANSI-C++, so that the migration to arbitrary operating systems and hardware platforms is possible with minor modifications.

 

All source codes of GeoDLL are directly compilable and executable under WINDOWS with Microsoft Visual Studio, Version 10 to 17. For the conversion to other platforms or other development environments adjustments in the source code are necessary.