An Overview of the Potential of UAV Applications to the Built Environment: A Role in Sustainable Urbanisation

Introduction

Currently there is a wide range of commercial small-scale airborne platforms available for acquisition of low-cost, high-resolution aerial remote sensing data. These include kites, model aircraft, balloons or blimps, helicopters, Unmanned Aerial Vehicles (UAVs), Unmanned Aerial Systems (UASs), and Drones (Green et al., 2020a). They have recently been complemented by waterborne drones operating both on the water surface and underwater carrying hydrographic sensors to monitor underwater structures and the impact of floating structures on the environment (De Lima et al., 2015).

In the past ten years, drones, UAVs and UASs have evolved from, relatively simple ‘toys’ with the capability to carry miniaturised RGB cameras for aerial photography and video footage, into mature aerial photographic systems for survey. The drone industry has quickly become professional and highly respected with major developments in aerial platforms and sensors including autonomous flight software, advanced flight controllers and First Person View (FPV) systems, accompanied by flight regulations, requirements for pilot training, and competency tests. The total market value of battery powered UAVs is expected to reach over 1000 million dollars by 2023 (Harrop and Harrop, 2014).

The rapid development of microelectronics and microprocessors, GPS and navigation systems, together with reduced costs over the last five years, have all helped to trigger an unprecedented demand for, and growth in, the use of UAV platforms and sensors for civilian applications (Watts et al., 2012; Colomina and Molina, 2014). This has been aided by advances in battery technology to extend duration of flight, the range of cameras and sensors available, and both softcopy photogrammetry and digital image processing software to generate mosaics, orthophotos, and DSMs and DTMs. In a very short time, drones have been applied to many new areas of work, including applications using vertical and oblique photography, precision agriculture and viticulture, river monitoring, vegetation mapping, forest and pasture surveys, coastal surveys, archaeological sites, and other examples including the ‘built-environment’. Besides traditional aerial photography, videography, and other imagery, the acquisition of stereo-photography to build surface models with the aid of softcopy photogrammetry has led to many examples where houses and other buildings have been accurately surveyed and modelled and the results viewed in an interactive environment for visual communication via the Internet.

This contribution seeks to present a contextual overview of the potential role of UAVs and the related technologies for monitoring, mapping. surveying, modelling, and visualisation of the ‘built-environment’ as the basis to explore their role in sustainable urbanisation.

Definition of the ‘built-environment’ includes applications of UAVs to both rural, city and underwater environments with emphasis placed on the collection of geospatial data and imagery at the building and community level. Both fixed-wing and multi-rotor UAVs have the capability to collect a wide-range of RGB, multi-spectral, hyperspectral, thermal and Lidar imagery. Together with low-cost digital image processing and softcopy photogrammetric software these provide the basis for generating 3D terrain and surface models of individual buildings, architecture, infrastructure, and communities, as well as asset monitoring, maintenance, and management. In the underwater environment, sonar, bathymetric Lidar, video, and multibeam sensors, add another dimension to the potential of these robotic platforms for data and image acquisition.

Consideration will be given to the use of other types of miniaturised non-imaging sensors (e.g. air quality) that can be carried on UAVs to capture environmental data. Input to Geographical Information Systems (GIS) and modelling/simulation software provides a basis for more visually realistic models of the ‘built-environment’ for utilisation in planning and decision-making. 3D visualisation software, Virtual Reality (VR), and Augmented Reality (AR) also offer new opportunities to engage the public in the planning process through participatory GIS and landscape fly-throughs with the potential to contribute to sustainable urbanisation.

Successful flight operation in built-up areas requires discussion about regulations and safety requirements. Illustrated with a few examples, the chapter concludes by examining ways that this technology will develop and evolve in the future.