Hexacopter UAV and Agisoft used to survey spoil tips at Greenside Lead Mines

View down the valley overlooking Tip 1 and the lower working areas at Greenside Lead Mines

View down the valley overlooking Tip 1 and the lower working areas at Greenside Lead Mines

At the end of July we were commissioned by the Lake District National Park Authority to undertake topographic survey of the three large spoil tips at the extensive Greenside lead mining complex near Ullswater in the Lake District. Archaeologically the site is of national importance and is protected as a Scheduled Monument. Future management of the property necessitated the present detailed topographic survey in advance of engineering works to maintain the stability and structural integrity of the large spoil tips. The buildings beneath the spoil tips are currently used as hostel accommodation.

Tip 1 precariously sat above the youth hostel at Greenside Lead Mines

Tip 1 precariously sat above the youth hostel at Greenside Lead Mines

Normally such a detailed survey, requiring close contours for the extensive complex would take an inordinate amount of time to survey using traditional survey techniques such as Total Station or even differential GPS.  Over the last few years we have been developing more rapid and cost-effective survey capability using various unmanned aerial vehicles (UAV) to photograph archaeological sites, which is combined with Agisoft software to create 3D models and contours of sites.

Preparations for surveying Tip 3 at Greenside Lead Mines with the hexacopter UAV

Preparations for surveying Tip 3 at Greenside Lead Mines with the hexacopter UAV

Part of the site was surveyed and excavated in 2003-4 in advance to engineering works on Spoil Tip 2 using traditional survey methods, but whilst that took a week or so to undertake the present UAV survey took a day of flying and setting in survey control to cover the entire mine complex.

Surveying at Greenside Lead Mines with our hexacopter UAV

Surveying at Greenside Lead Mines with our hexacopter UAV

The site was visualised in Agisoft as a digital terrain model in both solid form and also with the aerial photography draped over the top. The data from this model was used to create detailed contours of the earthworks at various scales which could then be used when drawing up the site.

Isometric view up the valley at Greenside Lead Mines - screen capture of a solid texture model in Agisoft

Isometric view up the valley at Greenside Lead Mines – screen capture of a solid texture model in Agisoft

Isometric view up the valley at Greenside Lead Mines - screen capture of a photo texture model in Agisoft

Isometric view up the valley at Greenside Lead Mines – screen capture of a photo texture model in Agisoft

The complete site was also output as a single flattened scaled composite image which was then annotated in the field to add in the finer detail of archaeological structures and provide hatchures to the topographic survey.

Agisoft xy topographic plot of Greenside Lead Mines

Agisoft xy topographic plot of Greenside Lead Mines

The finalised site drawings, contours and survey detail were then compiled into a single CAD drawing for the entire complex and figures created showing both the entire complex and detailed ones of specific features in the complex.

Finished topographic survey of Greenside Lead Mines

Finished topographic survey of Greenside Lead Mines

Detail of the topographic survey between Tips 1 and 2 at Green side Lead Mines - no photo

Detail of the topographic survey between Tips 1 and 2 at Green side Lead Mines – no photo

Detail of the topographic survey between Tips 1 and 2 at Greenside Lead Mines

Detail of the topographic survey between Tips 1 and 2 at Greenside Lead Mines