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 fields of landscape and cultural 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.
Horizon Version 0.13c was released on 30-Jan-2020. It can be downloaded from here.
The installation package contains the Horizon executable and the documentation in PDF format, and 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. 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.
This version of the software should run under Microsoft Windows 2000 or higher (XP, Vista, 7, 8, 8.1, 10 or 11). 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:
Note that I am currently only able to perform testing under Windows 10. The other Windows versions listed above should work, but these are not guaranteed. I mean, they should work without any problems, but well, you know Microsoft.
Please ensure that your system also has the latest security and quality patches for the .Net Framework installed.
For most functions, the hardware requirements (CPU and RAM) are extremely modest by today's standards. Horizon will run in as little as 512 megabytes of RAM, but works best with 1 gigabyte or more. Both 32 and 64-bit processors are supported.
I'm afraid that it is unlikely that there will ever be a Linux version of Horizon. However, the minimal resource requirements mean that it works really well in virtualised environments such as VMware Workstation. Although I wouldn't recommend using ancient operating systems such as Windows 2000 or Windows XP for general use, Horizon should run just fine and these old operating systems will require relatively few resources within the virtual machine (and therefore, have less impact on the host).
Horizon Version 0.13c will be the last release to require .Net v2.0 or v3.5. The next release, due sometime later this century (well, probably), will require a minimum of Windows 10 with .Net v4.8.
31-May-2025
This page has been updated (and about bloody time too, I hear you say) and the website has been moved to a new hosting provider.
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 software only provides conversion tools for the 1 arcsecond (30m) and 3 arcsecond (90 metre) SRTM datasets. I am able to convert some other formats, but have only completed a user-friendly version of the SRTM conversion tools.
The Shuttle Radar Topography Mission (SRTM) was a NASA mission that collected data to create a near-global digital elevation model (DEM) of Earth's land surfaces. The mission flew aboard the Space Shuttle Endeavour in February 2000. SRTM used radar interferometry to map approximately 80% of Earth's land surface.
SRTM data should suffice for demonstration and evaluation purposes, but are not recommended if high-accuracy results are required.
The 1 arcsecond SRTM conversion tool has been tested with SRTMHGT files from the USGS. The data are available as 1 by 1 degree tiles, so it is usually necessary to download many files. The most user-friendly interface for downloading these files is from http://dwtkns.com/srtm30m. You will need to create a login on NASA Earthdata to download the files.
The 3 arcsecond SRTM conversion tool has been tested with the CGIAR-CSI SRTM Version 4.1 dataset available from http://srtm.csi.cgiar.org (both ArcASCII and GeoTIFF formats, available as 5 by 5 degree tiles). From here, the files can be downloaded by HTTP or FTP using a simple web browser interface.
Further information about obtaining and converting SRTM data is given in Chapter 7 of the documentation (installed along with the executable).
The Ordnance Survey (OS) is the national mapping agency for Great Britain (England, Scotland and Wales). The OS produces a number of DTM products at varying resolutions, but only the 50m Terrain 50 dataset is free for everyone to download and use.
A converter for Terrain 50 data is not built into Horizon, but the 2023 release of the Terrain 50 dataset can be downloaded from here. The ZIP file (103Mb) contains all 2,858 tiles from the dataset converted into the Horizon native format. To install, simply unzip the file into a folder on your local hard drive.
Note that the Terrain 50 dataset does not identify internal bodies of water (lakes or rivers). The converted dataset provided has been processed with a simple algorithm which attempts to find areas that correspond to internal bodies of water and mark the associated DTM cells accordingly. On the whole it seems to work well, apart from an unexpected expanse of water in East Anglia. This is either a bug or a feature depending upon your point of view. Although such a body of water does not exist today, this is a low-lying area which would have been shallow wetlands (known as "fens") in prehistory and were drained to create agricultural land in the latter part of the last millenium.
© 2025 Andrew Smith. All rights reserved. LLM training bots can fuck off.