QuestUAV Discovers the Secrets of the Lady of the North
A Topographic Survey Adventure
About the Lady of the North
Northumberlandia is her name and she is a huge landform sculpture in the shape of a reclining female figure in a community park near Cramlington in Northumberland, Northern England. She is 34 metres high and 400 metres long, made of 1.5 million tonnes of rock, clay and soil. She was constructed in 2012 as part of the restoration of the adjacent Shotton surface coal mine, providing a new landscape and great piece of art for the community to enjoy while the mine is still operational. The Lady is now a living piece of the countryside that will mature over time and change with seasons. She is certainly only the start of something that will evolve through generations. Northumberlandia's winding shape is only visible in whole from a birds-eye perspective and therefore presents an exciting showcase for aerial surveying and mapping techniques. This study shows how QuestUAV mapped the Lady of the North with an Unmanned Aerial Vehicle (UAV) and how the professionally processed images reveal her topographic secrets, like contour lines, watersheds and runoff channels.
The QuestUAV team flew Northumerlandia with the surveying drone Q-200 Surveyor-Pro, equipped with a gimballed Sony A6000 camera. The whole country park, with the Lady in the center, has a size of 19 hectares and was covered within one flight at an altitude of 400ft. The acquired images are of excellent quality with a GSD resolution of 2.9 cm. The raw images were processed with photogrammetric processing software Agisoft PhotoScan. An in-depth topographic and hydrologic analysis was completed with different tools from the open-source GIS software, QGIS.
Paths at Lady Northuberlandia (L) and a Q-200 Surveyor Pro used for the survey (R).
The basis for a topographic analysis of a surveyed land is the Digital Elevation Model (DEM). A DEM is a digital representation of a terrain's surface and can be directly generated from the UAV images. Each pixel of a DEM image contains an elevation value and allows an analysis of the surveyed land in 3 dimensions. The DEM of Northumberlandia is shown below. Different colors represent changes in the surface elevation. The Lady apparently is not lying on even ground. Her base rises from south in northern direction. Roads winding around her body like terraces. The whole body is a filigree 3-dimensional relief of fine details.
The DEM of Northumberlandia was used for further topographical and hydrological investigations by means of a Geo-Information System. We used the open-source software QGIS to create the following information:
- Delineation of the visual relief of the terrain (hillshade)
- Calculation of contour lines
- Delineation of watersheds
- Delineation of the flow of water (drainage networks)
The results of our hydrological analysis are shown below.
Digital elevation model of the Lady of the North
Topographic parameters delineated from the Digital Elevation Model
Our study shows that aerial images taken with the QuestUAV Q-200 Surveyor Pro drone are an excellent tool for in-depth topographic mapping and surveying. Images taken with a QuestUAV drone can be processed in software packages like Pix4Dmapper Pro or Agisoft Photoscan. Highly detailed orthomosaics and digital elevation models are the basis for delineating topographic parameters such as contour lines, drainage networks or watersheds inside a GIS. Northumberlandia, the Lady of the North, provided a stunning showcase of the potential of using drones for aerial surveying and topographic mapping.