www.standingstones.org is a resource site for people who want to study Archaeoastronomy for Stone Circles, Standing Stones, Stone Rows and Henges.
Most of the source data for the site is sourced from the Megalithic Portal and would like to thank the Megalithic Portal for use of this data.
Archaeoastronomy (also spelled archeoastronomy) is the study of how people in the past have understood the phenomena in the sky, how they used these phenomena and what role the sky played in their cultures.
www.StandingStones.Org has a viewer to display the historic rising and setting points of the Sun and Moon - Viewer
The viewer has data accumulated from around 4000 sites across the UK and Ireland and many others from the rest of Europe including many Stone Circles, Standing Stones, Stone Rows and Henges.
The viewer images are based largerly on the SRTM (Shuttle Radar Topography Mission) data. LIDAR data is used for sites within England and Wales with missing areas filled with SRTM data. The SRTM data is also augmented with the Ordinace Survey (OS) based 50m map data. For UK Latitudes above 60 degrees (Shetland is mainly north of this) then OS data only is used.
For Scandinavia data for locations north of 60 degrees is from the VIEWFINDER PANORAMAS site and I would like to thank Jonathan de Ferranti for use of this data
The SRTM data is easier to process and generally produces cleaner results than the OS data although the SRTM data sometimes can vary from actual maximum heights by around 20m due to an average being taken across a tile (For instance, the SRTM tile for the summit of Snowdon is 20m below the top). The OS data is composed of 10M contour lines so provides better accuracy on steep slopes while the SRTM data is probably more useful on less steep terrain and hence both are used in conjunction. Spot heights where shown are from the OS data.
More details on most of the sites can be found at The Megalithic Portal.
Another useful reference site for many sites is The Modern Antiquarian.
Studies of the Stones Rows of Britain The Stones Rows of Great Britain.
Megalithomania.com includes all sorts of historic and prehistoric sites across Ireland, including Neolithic, Bronze Age, Early Christian and Medieval monuments although now only available on the internet archive. Megalithomania.com.
Lunar sites Scotland. It is interesting to compare the site in the Thom's long solstitial alignments article with the same sites in the StandingStones Viewer (Ballochroy and Kintraw)
mega-what.com provides accurate surveys the Whole Horizon around some sites - useful comparison site
The following are example images taken from a small group of Standing Stones in Anglesey (Druid Farm, SH416751, 53.24921, -4.375564) and shows how the location could have been used to observe the sun and moon at different positions.
The Winter Solstice rising of the sun over Snowdon
Major Lunar Standstill (-E-I) rising over Trum Y Ddysgl
The goal of the viewer is to show the view from a monument and overlay the rising and setting positions of the Sun and Moon.
The site attempts to make study of these sites easier and provides a generally accurate representation of what could be observed historically from a site.
For the Sun, the Winter and Summer Solstices, Equinox and Cross Quarter (XQ1, XQ2) positions are shown
For the Moon the Major and Minor Lunar Standstills are shown (+e+i, +e-i, -e+i and -e-i)
The viewer can take several parameters including the following
name=string - this is a case insenstive search string
country=Country Code (IM GG JE IE FR BE CZ PL DE GR PT NO SE CH ES MT IT DK NL UK XX)
area=County - the area of the country
type=All|Stone Circle|Standing Stones|Standing Stone (Menhir)|Stone Row - Alignment|Henge
grid=None|grid|fgrid - Specify whether to include a grid (1 degree intervals) or a fine grid (10 minute intervals).
res=High|Med|Low - Specify the image resolution (120, 60 or 30 pixels per degree).
label=None|labels - Display spot heights from OS Maps if available.
year=3700|4000|4500|5000 - Select the year - either 1750BC (3750), 2000BC (4000), 2500BC, (4500) or 3000BC (5000).
zoom=5|10|15|20|30|40|60|80|100|120|140|180 - Specify the Zoom Level.
x=0|360 - Specify the image X position in Degrees from 0 (North) to 360.
y=-1|20 - Specify the image Y position in Degrees from horizon (-1 to 20).
A type URL would be something like the following
http://www.standingstones.org/viewer.html? grid=grid&res=High&label=labels& year=5000&area=Gwynedd
The following is a screen shot of the Sun and Moon calculator showing some of the maths for the Moel Y Llyn Stone Circle for the distant moon set. Probably not very pretty but very useful for working out bearings, distances, Grid Refs and generally checking results. It now calculates the rising and setting positions of the sun/moon assuming a rise or set over the sea.
SunAndMoonCalculator.zip - ZIP of the calculator
In order for the calculator to access height data, this must be stored within a folder called "%appdata%\SRTM Data\". The SRTM tiles (e.g. N27W013.SRTMGL1.hgt.zip) can be downloaded from 30-Meter SRTM Tile Downloader
In additional, for those with Excel, there is a basic calculator written in XLSX EarthNumbers.xlsx - Simple Excel based calculator This calculator is based on the same maths as the rest of the site although the refraction calculations work are somewhat different.
The images on the Stnding Stones web site are produced by a program called Panorama which is now available to download from this link Panorama.zip - ZIP of the program.This program is still a work in progress so there are some rough edges.
Panorama is able to use SRTM, OS 50m data and LIDAR data to draw landscales. Now supports wireframe output.
Multiple command lines options are available:-
-drawJobs (draw cairns, stones etc)
-PosRange <angle> - Draw degrees above horizon
-NegRange <angle> - Draw degrees below horizon
-lidar (Process LIDAR data for locations
-lidarfolder (Location where the LIDAR source data is stored (ZIPs and ASC files)
-lidarcache (Location to save processed binary LIDAR cache data for later use
-lidarrange MaxDistance (Maximum distance (m) from observer to use LIDAR data (default 10000)
-r (replace file)
-country <xx> - short country code, e.g. FR for France
-CountryLong <country> - long country name, e.g. France
-hf <height> - Height Filter
-locs (dump location GPX files)
-mr - Create multiple resolutions of images (30, 60 pixels per degree)
-ch - Save Horizon GPX File
-pp - Create Passing Points, where the sun/moon cross the horizon
-labels (spot height labels)
-spots (Add OS spot markers)
-nospots (Don't add OS spot markers)
-contours (Add OS Contours)
-srtm (Use SRTM Data)
-grid (add a grid)
-fgrid (fine grid)
-allgrids (Create files with no grid, grid and fine grid in one go)
-stellarium (Generate Stellarium ZIP file)
-srtmFolder <folder> - SRTM Source folder name, e.g. %USERPROFILE%\Appdata\roaming\SRTM Data
-osFolder <folder> - OS Maps 50M data FOlder e.g. %USERPROFILE%\Appdata\roaming\OS Terrain 50
-p Pixels (pixels per degree - default 120)
-oldcsv <oldcsvfile> - Not really used any more
-json JSONOutFile (Create JSON File)
-max MaxDistance in M
-t (Create Template file)
-csv CSVFiles (Bulk process from a list of CSV files)
-threads N (Number of threads to run)
-Solstice - Draw Sun Solstices
-Equinox - Draw Sun Equinox
-xq - Draw Sun Cross Quarters
-Moon+e+i - Draw Moon +e+i
-Moon+e-i - Draw Moon +e-i
-Moon-e+i - Draw Moon -e+i
-Moon-e-i - Draw Moon -e-i
-AllSun - Draw all Sun positions
-AllMoon - Draw all Moon positions
-CacheLIDAR N (Number of LIDAR tiles to cache (400MB per tile, default 4)
-CacheSRTM N (Number of SRTM tiles to cache (26MB per tile, default 12)
-CacheOSMap N (Number of OS Map tiles to cache (few MB each, default 150)
-ColourSea <RGB> - Default is Hex RGB (e.g. 000000) for Black
-ColourSky <RGB> - Default is Hex RGB for Blue
-ColourBase <RGB> - Default is Hex RGB for DarkGreen
-ColourTops <RGB> - Default is Hex RGB for Brown
-ColourDistant <RGB> - Default is Hex RGB for DimGray
-ColourOriginLatitude <latitude> - default 45
-ColourSlopeAdjust <int> - default 20
-ColourMaxDist <metres> - default 10k
-ColourGreenBrownShades <count) - default 40
-ColourGreyCount <count) - default 80
-ColourMaxHeight <height> - max height colour in metres
-ColourMoon <RGB> - Default is Hex RGB for Grey
-ColourSun <RGB> - Default is Hex RGB for Yellow
-ColourSaMText <RGB> - Sun and Moon Text - Default is Hex RGB for Black
-ColourTitle <RGB> - Default is Hex RGB for White
-ColourCairns <RGB> - Default is Hex RGB for Red
-ColourStones <RGB> - Default is Hex RGB for DarkGrey
-ColourSpotHeight <RGB> - Default is Hex RGB for Dark Red
-ColourReticleBackground <RGB> - Default is Hex RGB for White
-ColourReticleMajor <RGB> - Default is Hex RGB for Dark Grey
-ColourReticleMinor <RGB> - Default is Hex RGB for Grey
-ColourReticleHorizontal <RGB> - Default is Hex RGB for Black
-ColourReticleText <RGB> - Default is Hex RGB for Black
-CopyrightNotice <Text> - Change Copyright Notice Text
-DumpHeights <string> - Where string is latitue, longitude, lat Increment, lon Increment, lat Count, lon count (e.g. "53.068053, -4.076761,2.777777777777778e-5,2.777777777777778e-5,100,100")
-MaxJobs <number> - Stop processesing after at most N jobs (the MSFT ZIP library leaks badly so useful to restart after N jobs - for LIDAR sites set N to ~3)
-ProximalInterpolation - Perform Proximal Interpolation rather than Linear (Mincraft mode)
-ObserverHeight <height> - Observer eye height (1.5m)
-SiteTypes = <types> - where default types are "Stone Circle,Ring Cairn,Standing Stone(Menhir),Standing Stones,Stone Row / Alignment,Henge,Multiple Stone Rows / Avenue,Viewpoint"
-BlobStoreURL <URL> - where URL default is "https://standingstonesorg.blob.core.windows.net/"
-ViewGPSURL <URL> - where URL default is "https://gpsvisualizer.com/atlas/map?url="
-ViewImageURL <URL> - where URL default is "http://www.standingstones.org/viewer.html?name="
-MegpURL <URL> - where URL default is "https://www.megalithic.co.uk/article.php?sid="
-StandStonesHost <URL> - where host default is www.standingstones.org
The following is a screen shot of the Panorama UI program showing a couple of example renders of Castlerigg, one part way through and the other after completion. A hopefully useful front end to the command line panorama program.
Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D like you would see with the naked eye, binoculars or a telescope.
Each site in the Viewer has a Stellarium ZIP file link - this link allows you to download the landscape in a format suitable for input into Stellarium. Within Stellarium, hit F4 and then select import landscape to play.
The following is an example image from Stellarium of the Mid Summer Sunset from Raven's Stone, Elgol on Skye
A map of the North Preselis generated my "Stone Circle Detector" program that generates a map of where setting/rising of the sun/moon can be observed for various foresights.
A map of the Anglesay generated my "Stone Circle Detector" program that generates a map of where setting/rising of the sun/moon can be observed for various foresights.
Sometimes the LIDAR and OS Map data heights diverge from each other and where this happens, the rendering can be somewhat off. The LIDAR Check Link below page shows locations where there are OS Map points (either spot heighs or contours) with heights that are 4m or more different than the LIDAR data.
This often occurs when the location is in woodland, at the edge of the sea, in quarries or locations where building work has occurred. Luckily instances where the values for hilltops being significantly out is quite rare.
An example of this is for the Nipstone (52.566630, -2.950539) which seems to have been largely removed by the LIDAR processing - SO39 Map that covers the Nipstone
Copyright David Hoyle 2021.
Maps images by Captain Blood - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=930331
By Maximilian Dörrbecker (Chumwa) - Self made, using Northern Ireland - Counties copy|this map by NNW, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=7918534
This Serbia map file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. https://creativecommons.org/licenses/by-sa/3.0/legalcode