Tag Archives: aerial photography

Rhynie Excavations Season 4 (2016)

By Cathy MacIver (on behalf of the REAP Project Team)

A fourth season of excavation took place at the Craw Stane, Rhynie over August – September 2016. The project was led by REAP Project Directors Dr Gordon Noble, University of Aberdeen and Dr Meggen Gondek, University of Chester.

Aerial photographs and geophysical surveys had identified curvilinear enclosures around the Craw Stane, one of the few symbol stones remaining in situ in Scotland (Plate 1).

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Plate 1: Craw Stane with Tap O ‘Noth hillfort (©Cathy MacIver)

Previous seasons of work at the Craw Stane (one of seven Class I Pictish symbol stones from the area) in 2011, 2012 and 2015 had demonstrated that these enclosures took the form of an inner and outer ditch and a later palisade structure with associated postholes.

Excavations in past seasons had revealed a number of high status objects including fragments of Late Roman Amphora, glass beads, metal pins, glass vessel fragments and evidence of metal working in the form of metal working tongs, slag (metal working waste) and clay moulds for metal objects. The features date the site to the early medieval period and radiocarbon dates from the ditches and other internal features confirmed a relatively short 5th-6th C construction, occupation and abandonment of the site.

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Plate 2: Rough draft of the excavations from 2011, 2012 and 2015. A work in progress!

The 2016 excavations aimed to investigate areas of the site that hadn’t been looked at before, continuing to use the successful strip and map approach employed in previous years. This involved 4 large areas or trenches (Plate 3) where the topsoil was removed by machine and watched by archaeologists. The areas were then cleaned by hand by a team of archaeologists, students and volunteers, using hoes, krafses and eventually trowels. This made archaeological features more visible and easier to record. Plans of the site were created using DGPS (accurate to the nearest cm) and aerial photography using a drone. Areas with more complexity were drawn by hand.

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Plate 3: Aerial view of the 2016 trenches

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Experiments using a Quadcopter for Archaeological Aerial Photography

by Alan Thompson (NOSAS)

Introduction

I’ve had my Quadcopter for over a year now, had great fun flying it, and have produced many interesting images.  I recently showed a selection of images at a NOSAS evening, and was asked if I would write this blog and share some of the things I’ve learned along the way.

Of course the pictures are what it’s all about and even if you’re not interested in my comments, I hope you enjoy looking at them.

Background

Inspired by some of the wonderful aerial photos (APs) I’ve seen (for example on Canmore) I have long thought how good it would be to be able to take such pictures of our own archaeological sites.

For several years I have been interested in photogrammetry and experimented with that, especially of rock art where the production of a 3D surface and use of computer generated lighting and shadows can give some great effects.

In 2013 I began to investigate kite aerial photography (KAP) but the possibility of using a Quadcopter also emerged and I realised that technology and prices were moving so quickly that it might be a better option.  In early 2014 I decided that the only way to learn was to buy one.

The Quadcopter – getting ready to fly

Most amateur Quadcopters are sold with very wide angle cameras, with the intention of video recording, and also providing a pilot’s view (called first person view or FPV).  This is less than satisfactory for archaeological aerial photography, and so I bought a Quadcopter without a camera, with a view to fitting my own.

The camera is obviously critical, and it needed to be light (ideally <300g including battery), robust, of good enough quality, and with an interval timer.  Unfortunately I could find no such camera.  All those with interval timers are heavier, for example those used for kite aerial photography.  A solution can however be found in that a group of people spend their time hacking the software of Canon cameras (google CHDK) and provide a hacked version for some models which enables an interval timer to be run.

Having bought and hacked my camera and got the interval timer working I had to fit it to the Quadcopter.  The main problem is the high frequency vibration from the rotors which renders the pictures useless.  A suitable anti-vibration mounting was needed, all within the weight limit.

Next, to prepare for the first test flight.  The web (YouTube) is full of videos of alarming crashes and fly-aways.  The Quadcopter instructions are daunting saying that a first flight should be from the middle of a large field, with no wind and no people about.  There is also the matter of insurance (it could certainly hurt someone badly), and the possible need for a CAA licence.  The regulations here are changing quickly but at present as a hobby flier I can insure through the British Model Flying Association (BMFA), and (unlike a professional archaeologist) have no need of a CAA licence provided I fly within line of sight, avoid certain areas (eg near airports) and limit the height.  I would again emphasise that this is all very much in the news and changing and my observations here will quickly be out of date.

Quadcopter flying

The first flight is bit nerve-racking, but set to auto mode the Quadcopter uses its own GPS and compass and is set so that (more or less) if you let go of the controls it just hovers where it is.  Flying in this mode is reasonably straightforward.  I have not dared try any of the advanced modes as yet.

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Pictish Burial Practices and Remains

by Roland Spencer-Jones (NOSAS)

These notes are in preparation for NOSAS field trips to two recognised Pictish cemeteries in the Highland region –

  • Garbeg near Drumnadrochit on Saturday 1st November 2014. See Highland Council HER, RCAHMS Canmore
  • Whitebridge near Foyers on Sunday March 8th 2015. See HER, RCAHMS Canmore

(See also separate post about Garbeg and Whitebridge cemeteries).

The Picts, those most elusive of early medieval Scottish peoples, seem to have disposed of their dead in a variety of ways. Remains that can still be found in the landscape include cremations, simple burials in the ground, long cist burials, burials under cairns, and burials under round and square barrows. It is also probably true that disposal was achieved by exposure and excarnation – practices continuing from pre-history. What remains unclear is how any of these contemporaneous burial practices were chosen for a specific individual or group.

An Artist's Impression of Pictish Barrows

An Artist’s Impression of Pictish Barrows by Alan Braby

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