Droning on about Tarradale

by Andy Hickie

Drone image of Tarradale Through Time barrow cemetery dig, as featured in “Current Archaeology” November 2019.

Back in 2017, I caved in to the demands of consumerism, and purchased a new quadcopter, a Phantom 3 Advanced, which is equipped with a camera and GPS unit. I flew multiple flights around Avoch but, after a while, the novelty of seeing one’s house from the air at different angles and altitudes begins to wear thin, and I began to wonder what I could actually do with a drone. Having always had an interest in archaeology and, spurred on by seeing some of the images Alan Thompson of NOSAS had created, I decided to carry out a few experiments of my own.

My first flights took in locations such as the distillery and settlement at Mulchaich, and the features of Kinbeachie castle – sites which had already been mapped by Alan by drone, the results of which I could use as a ‘benchmark’ against which I could compare those of my own.

At the same time, I began experimenting with various flight planning apps which allow for off-line autonomous flight planning, as well as online platforms for image processing. I found that “DroneDeploy” and “Mapsmadeasy” combined provided a fairly user-friendly pipeline, whereby image capture and photogrammetry can produce georeferenced photomosaics and digital surface models (DSMs). These can then be imported into software such as QGIS for further processing.

Having found the software which satisfied my needs, I then turned my attention to potential sites which I could map – and decided on the cropmarks of the Barrow Cemetery at Tarradale. At this point, my intent was purely to satisfy my own curiosity – just to see what I could see, and how it would compare with the archaeology found at the forthcoming 2019 dig.

And so, on 10 June 2018, accompanied by my daughter Emma to act as co-pilot and “spotter”, I visisted Tarradale to map the area with the drone. I can still recall the excitement I felt as the images began to appear on the monitor of the remote controller, which showed the cropmarks were developing. However, my satisfaction was tempered somewhat when I got home and began to process the photographs. Although the cropmarks were indeed evolving, the crop was insufficiently ripe, and many of the details remained hidden (see image below).

Pictish Eagles and the Strathpeffer Stone

by John Wombell (NOSAS)

There are 12 known Pictish Eagle carvings, all in the RCAHMS publication of 2008 ‘The Pictish Symbol Stones of Scotland’.  They vary considerably and by far the best known and the best preserved is on the Clach an Tiompain at Strathpeffer (HER MHG43542) meaning the ‘sounding stone’ but known more widely as the Eagle Stone.

There are many images of it in circulation but a week ago I took a new set of photos which Alan Thompson kindly processed for me using photogrammetry (see images above and below, as well as on Sketchfab).  The reason behind this was that I wanted to try to produce an engraving of it on wood and needed to see more detail that is not visible to eye or touch at the stone.

The Eagle Stone has had several lumps bashed off it in the past removing part of the horse shoe symbol and the eagle’s rear end.  Otherwise damage to the carving is minimal with only part of the eagle’s leading leg either fallen or bashed off.

My dilemma was whether to give the eagle a tail or not.  I feel sure that unlike most Pictish eagles this one was drawn from a live eagle depicted walking.  It is correct in a lot of detail even though the carving is full of symbolism.  I decided to give my version a short dipped tail represented as two feathers after one of the Orkney eagles.