Horizon is a GIS tool designed for archaeoastronomers investigating alignments of prehistoric monuments with astronomical phenomena (e.g. rising and setting of the Sun, Moon and stars). It gets its name from its primary function, which is calculating accurate horizon profiles using DTM/DEM mapping data. More generally, it is a landscape visualisation tool which can generate full 360-degree panoramic scenes using 3D rendering techniques, which may have some applications in the field of landscape archaeology. Possible applications include:

This program is not, and never will be, a realtime virtual reality (VR) simulator, a tool for rendering photorealistic images, or a planetarium simulator. There are plenty of other programs around that do these things better.


The software will run under Microsoft Windows 2000 or higher (XP, Vista, 7, 8, 8.1 or 10). In addition, it requires that the Microsoft .NET Framework Version 2.0 be installed first, if it has not been so already. The package you will need to install (if any) depends on which version of the operating system you are running:

Please ensure that your system also has the lastest security and quality patches for the .NET Framework installed.

For most functions, the hardware requirements (CPU and RAM) are modest by today's standards. Horizon will run in as little as 512 megabytes of RAM, but works best with 1 gigabyte or more.

The executable is distributed as a MSI (Microsoft Installer) package, so installation is largely automatic. The installer isn't very smart, so it is a good idea to manually uninstall the previous version, if any, before you install the new version (through Control Panel - Add or Remove Programs). Then click on the installation package and follow the prompts.


The installation package contains the Horizon executable and the documentation in PDF format. The installer will create links to both the executable and the documentation in the Programs menu under the Start button, as well as an icon on the Desktop.

Although you should ideally download and install the latest version, the last few versions will be retained in case you experience problems and have to go back to an earlier version (available here). The following lists only the most important changes since the last publicly-released version. Detailed information about the changes in each version is given in the PDF documentation.



Just letting you all know that Horizon is still under active development and that a new version will be released soon. I have been somewhat busy with other projects, both professional and personal, over the last few years and Horizon is very much a spare-time project for me. Nevertheless, there have been a large number of changes to the software motivated by my own archaeoastronomy needs, but I simply have not had the time to document and test everything for general release. I think things are finally at the point where I can concentrate on preparing for a general release.

This is how I currently see the releases for the near future:


For various reasons (primarily efficiency), Horizon uses a proprietry file format for DTM data.  There are many existing file formats for DTM data, but none of these are directly supported.  Data files will need to be converted into a format compatible with Horizon. Currently, the the software only provides a conversion tool for the 3 arcsecond (90 metre) SRTM dataset. I am able to convert some other formats, but have only completed a user-friendly version of the SRTM conversion tool. This should suffice for demonstration and evaluation purposes, but is not recommended if high-accuracy results are required. Please contact me if you have data in other formats.


The SRTM conversion tool has been tested with the CGIAR-CSI SRTM Version 4.1 dataset available from http://srtm.csi.cgiar.org. From here, the 5 by 5 degree tiles can be downloaded by HTTP or FTP using a simple web browser interface. Alternatively, the data can be obtained from http://www.ambiotek.com/srtm, which uses a rather more sophisticated interface based on Google Earth.

Further information about obtaining and converting SRTM data is given in Chapter 7 of the documentation (installed along with the executable).

Ordnance Survey

Coming soon!

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