Adam Ibbotson and @WC21UKProductionsLtd published a Youtube video today - below - in which they notice an unrecorded henge like shape. Of course I had to find it using the Lidar Lens, link above. Intriguing. Watch the video for more:
Adam comments:
More like “stumbled upon” / rediscovered 😅 As mentioned, Mr Phil Barrett emailed me a screenshot of one of them 4 or 5 years ago. He found they were already recorded.
Wiltshire Museum is redeveloping the old Assize Courts. To help me visualise the plans I built a 3D model from the planning drawings so you can see the building as it is now and as it's planned. You can walk round it, look inside the courtrooms and entrance hall, and switch between the two views.
I'm an amateur, and this is version 1. It was made without specialist architectural tools, from the published planning drawings, LiDAR and open map data. It won't be perfect, but I don't think it's bad. Corrections are welcome. The interiors still need refining.
Explore it here: https://timdaw37.github.io/assize-courts-3d
The model is open source and free to reuse. The code is on GitHub at TimDaw37/assize-courts-3d under the MIT licence, so you can copy it, adapt it and share it, as long as you keep the credits. If you spot something wrong, such as a window in the wrong place, a missing detail or a height that looks off, please tell me in the comments or raise an issue on GitHub. Please keep the data credits (Environment Agency LiDAR, OpenStreetMap, Historic England and OS) when you reuse it.
The two landscape fly-throughs, Avebury and Stonehenge, have been rebuilt from the ground up. Both were first made on Ordnance Survey Terrain 50, a 50 m height grid with 10 m colour bands. That is fine for the shape of the downs, but nothing archaeological survives in it: Silbury Hill had to be cut out of the terrain and modelled, and every bank and barrow was drawn on top of a surface that could not show it.
Both models now stand on the Environment Agency's 1 m LIDAR terrain model. The ground is a 5 m (Avebury) or 6 m (Stonehenge) mesh for shape, shaded from the full 1 m data, so the henge ditch, the barrow groups, the lynchets and the hollow-ways are the surveyed surface rather than a drawing of it.
Each model now has two views.
The reconstructions are indicative: the plan is the surveyed one; the heights and depths are typical original dimensions, not measurements.
The Stonehenge model goes further. Its monuments now come from Historic England's aerial investigation mapping, the bank and ditch outlines plotted from aerial photographs and LIDAR, rather than from OpenStreetMap points. That data puts 843 prehistoric bank and ditch features in the frame, sorted into the phases by monument type and period.
For each mapped earthwork, the as-built view lays down a 2 m surface: the LIDAR with the surviving earthwork smoothed away, and the bank and ditch rebuilt on the mapped plan.
The stones, the timber circles at Woodhenge and Durrington, Larkhill causewayed enclosure and West Amesbury henge are placed by hand from published plans. Larkhill and West Amesbury leave nothing visible in the LIDAR.
They are heavy pages, built for a desktop or a large screen. On a phone, adding ?lite to the address loads a coarser mesh without shadows; very old phones may still not manage the Stonehenge textures.
The Stonehenge model is the phased, as-built companion to the Stonehenge landscape flyover, which stays the place for the ground as it is now, the sky and alignment checks.
Ground: Environment Agency LIDAR Composite DTM 1 m, © Environment Agency copyright and/or database right 2022 (Open Government Licence). Monuments: contains Historic England data © Historic England 2026 (Open Government Licence), aerial investigation mapping; © OpenStreetMap contributors (ODbL). Reconstructions are indicative.
The previously blogged Wiltshire run is the second half of a much longer sortie. NARA holds 254 prints from the two cameras under box GX 10484, and the item records place them on a single loop. The aircraft crossed the Devon coast at Sidmouth (L 1), flew north past Honiton to the Blackdown Hills, then north-east by Taunton, Bridgwater and the Levels to Cheddar, the Mendips and Bristol. North of Filton it turned east and south, and came back by Doynton and Keynsham to Bath and Freshford, where the Wiltshire frames begin at L 109. After Wiltshire it crossed the New Forest and left the coast at Barton-on-Sea (L 148): some 255 km on the long-lens camera alone.
The film above joins the long-lens frames from Cheddar to Freshford, L 56 to L 108. Fair-weather cumulus covers much of the Mendips, Dundry and Bristol (L 62–88); the ground still matches between the clouds, so the frames join, but the clouds sit far above the ground and shift between exposures. Exposure 86 and exposure 91 are not in the NARA set. L 86 is bridged by a small overlap between 85 and 87; L 91 leaves a short break in the film.
Over Bristol the frames come closer together. Over the Mendips successive frames are about 1,000 scanned pixels apart, over the city about 600, and the camera clocks agree: roughly one exposure every 20 seconds from L 56 to L 76, against one every 10 seconds from L 76 to L 85 (minute-hand readings by eye, good to about half a minute). NARA lists L 87–92, north of Filton, as obliques, although at least L 88 appears near-vertical; the label may reflect the aircraft banking into the turn. No record found names a target.
Bath is clear. On L 105 the Royal Crescent and the Circus stand out above Royal Victoria Park, seventeen months before the air raids of April 1942.
Bath on L 105, 29 November 1940: the Royal Crescent (centre) facing Royal Victoria Park, with the Circus above it. Turned to read roughly north-up. Luftwaffe, NARA RG 373, GX 10484.
Bristol through broken cloud, Bedminster to Ashley Down, L 76–84.
The landscape film runs at about four times real speed and is turned so that the aircraft flies left to right. Each frame is captioned with its exposure number, NARA's nearest place name and its clock reading. The Cheddar to Bath film is a director's cut, without captions, and ends where the Wiltshire film begins. The music is original.
All photographs: Luftwaffe, 29 November 1940; US National Archives, RG 373, GX 10484, listed as Use: Unrestricted. Frame matching, measurements and film: T. Daw. Methods and scripts: github.com/TimDaw37/wessex-films.
This is a side-hustle from my Ramson Cliff erratic post. While I was looking through the 1940 German reconnaissance photos for that, I wondered whether we could show the effect of rising sea levels on the beaches at Woolacombe and Saunton.
The result is a small interactive map: Woolacombe and Saunton at 12:44 BST, 31 August 1940.
To make it fair, we matched the position in the tide cycle as closely as we could with modern satellite photographs, then overlaid them. Matching the tide height alone isn't enough. On a flat beach, where the water's edge appears also depends on:
For example, a Sentinel-2 image from 27 September 2018 caught the sea at almost exactly the 1940 height. But the tide was falling, 100 minutes before low water, on an 8.3 m spring tide. It looks similar, but it isn't the same moment. So I kept only modern images taken on a rising tide, within 20 minutes of the 1940 timing, and with a tide range within 1.5 m of 1940's.
The photographs were matched in the following manner:
Newlyn, the gold-standard tide gauge, shows about 20 cm of sea-level rise since 1940. On Woolacombe's gentle beach, 20 cm moves the waterline only about 8 m. On the flatter sand at Saunton the LiDAR puts it at around 20–30 m.
On these sorts of beaches it's invisible. Sand moving about and the natural spread of the waterline swamp it. On 1940 film, wet sand and shallow water look alike, so the 1940 edge alone can shift by up to 50 m depending on how it's read. Of 106 modern Landsat and Sentinel-2 readings, 27 match the 1940 tide. On those, the water's edge sits a median of −0.08 m from the predicted tide at Woolacombe and +0.16 m at Saunton. Neither shows a trend that stands out from the noise. The rise is real, but you measure it with a tide gauge, not on a sandy beach.
Explore the map. 1940 photos: U.S. National Archives, RG 373. Contains modified Copernicus Sentinel data. LiDAR © Environment Agency (OGL).
The Ramson Cliff boulder has had me hooked for over a year now (the mystery, the 2025 visit, the second thin section and last month's post), and the full story is in the paper in Quaternary Newsletter 167. One question kept nagging at me. The stone was found in 1969 at SS 4356 4070, out in the field on Baggy Point, and moved to the field edge in the early 1970s. Was it already sitting there in 1940, and would a wartime aerial photograph show it?
So I flew in to have a look, using a Luftwaffe reconnaissance photograph taken over North Devon in the summer of 1940.
The photographs come from Luftwaffe sortie GX 10006 SD, flown on 31 August 1940. Each frame has the camera's clock photographed in the corner. The clock in the neighbouring frame reads 12:45 BST, which puts the frame over the find spot at about the same moment. I lined the frames up against the modern map, tightening the fit around Baggy Point using the field banks that show on the Environment Agency LiDAR. Then I stitched them into a mosaic and flew a virtual camera in from the south over Croyde, descending and tilting down until it looks straight down on the target.
On the approach: the 1940 fields of Baggy Point, built from sortie GX 10006 SD.
The limit is resolution. The National Archives scans of these frames come out at about 1.5 m per pixel on the ground. The boulder is 105 x 55 x 38 cm and weighs 378 kg, so it is smaller than a single pixel. I never expected to see the stone itself. What I was looking for were the things a big stone in a field does to the land around it: livestock tracks converging on it, a trampled or poached patch, ploughing that bends round it, or an unploughed island left where the plough couldn't go.
Over the target: the circle marks the 1969 find spot, SS 4356 4070, on the 31 August 1940 photograph.
Honestly, nothing. In 1940 the find spot lies in a strip of grass inside the cliff-top boundary. With the contrast pushed up there are no tracks running to it, no worn patch, and no sign of cultivation avoiding it. The other photographs I have looked at, GX 11967 (23 March 1941) and RAF 106G/LA/132 (14 February 1945), are no clearer. That doesn't prove the stone wasn't there: a stone smaller than a pixel in a grass field could easily leave no trace. But the wartime air photos can't settle it either way.
The film ends on the LiDAR, which picks out the cliff-top field edge where the stone sits today.
Aerial photographs: US National Archives, Record Group 373. LiDAR: Environment Agency, contains public sector information licensed under the Open Government Licence v3.0.
