UAV Update

Dunsapie Loch in Holyrood Park

We have been making good use of our DJI Phantom UAV over the summer.  We took it out to Traprain Law in East Lothian in May as part of Sandy Avery’s MSc dissertation to test the capabilities of this device and flew for more than an hour over a marked set of ground control points. We had fitted a new camera – a Canon Powershot SX230 HS, which is 12.1 megapixels, has a 14-times optical zoom, but weighs just over 200 grams. This camera has some interesting features; firstly it has an internal GPS although we haven’t tried that yet. Secondly it can be controlled and customised by a scripting language, which allowed an intervalometer function to be installed which allows images to be taken regularly without ground control. The images we have taken were markedly better than those taken with the GoPro device we used previously. The GoPro suffered from a fish-eye lens, so wide-angle that it was of limited use for building an orthophoto – corrected to its exact position on the earth. The resolution of the images was notably better leading to a marked improvement in DEM and orthophoto quality. With further work there are many possible survey and visualization applications which the Phantom could be used for in the future.

We have also flown at Skinflats near Falkirk, recording the margin of the saltmarshes along the Firth of Forth as part of Jethro Gauld’s MSc dissertation in Ecosystem Services, and have also flown in Holyrood Park in Edinburgh, with permission from the Historic Scotland rangers. Our flight in Holyrood Park last week was in some of the best conditions possible, with virtually no wind and a beautiful sunny day.

EEO-AGI Scotland Seminar Review : Dr. Ruth Swetnam : 9th May

The EEO/AGI seminar on the 9th May was presented by Dr Ruth Swetnam from Staffordshire University. The presentation was titled “Quantifying cultural ecosystem services provided by the landscapes of Wales”. The project looks at adapting current ecosystem services workflows from dealing with quantitative objects to focussing on more qualitative elements of the world. Through this it hopes to be able to quantify the effectiveness of current Welsh Government spending on preserving and improving the Welsh countryside through the Glastir program.

The project is funded by the Welsh Government and builds on existing work done by Natural Resources Wales, The Countryside Survey and The Historic Environment records of the Welsh Archaeological Trusts.

The aims of the project are to:
• Assess the quality of the landscape through the selection of certain criteria
• To quantify the visual accessibility of the landscapes from the Welsh Right of Way network.
• To quantify the amount of historic assets and their condition within the landscape
• To quantify how the environment and the assets within it are changing over time due to Welsh government schemes and policies.

In order to accomplish these aims Wales was split up into a grid made up of 1km2 squares. From this grid 45 squares where chosen at random, with another 45 chosen in priority areas of the country. These squares where then surveyed in-depth. The 1km2 areas where then broken down into smaller 250m2 areas which then placed into an unweighted index, called the Visual Quality Index (VQI). This index attempts to quantify the key components of a landscape and allow a value to be assigned to it. This index was created in order to satisfy the requirements of a multitude of interest groups as well as take input from the general public.

The second stage of the methodology of the project was to look at how accessible the surveyed 1km2 areas are. This was done by carrying out a multi-criteria viewshed analysis from multiple points along the Welsh Right of Way network. This analysis took into account visual barriers such as fences, trees and buildings as well as the underlying terrain through the use of DTMs. This viewshed analysis was then combined with the VQI. This has the potential to both help direct the government initiative towards more accessible areas as well as allow the Welsh Government to improve the route network.

The project itself has great potential for further work in the future such as looking at overall accessibility from urban centres as well as allowing further refinements to the VQI. However, even without these refinements it is already an impressive first step at assessing value for money in Government projects.

Sandy Avery
(MSc in GIS at the University of Edinburgh)