Both fixed-wing and multirotor platforms are increasingly being identified as potentially useful airborne platforms for a range of professional environmental remote-sensing applications, including both expensive high-end specialist solutions and lower-cost, off-the-shelf commercial options. Small UAVs are ideal for applications where aerial coverage requirements are small, flying experience and expertise are limited, and the operating budget is usually relatively small.
With advances in battery technology, navigational controls, and payload capacities, many of the smaller UAVs are now capable of utilizing a number of different sensors to collect photographic data, video footage, and multispectral, thermal, and hyperspectral imagery as well as LiDAR.
With the aid of specialist digital image processing and soft-copy photogrammetry software, aerial data and imagery can be processed into a number of different products including ortho-photos, mosaics, and digital elevation models (DEM), then analysed to generate useful information for input to a GIS.
This chapter begins by examining the history of small-scale aerial (SSA) platforms for aerial image acquisition as the context for the current growth in the popularity of UAVs, the associated technologies, and the range of small-scale sensors currently available for environmental monitoring, mapping, and modelling applications. This is taken together with image processing, analysis, and information extraction as well as soft-copy photogrammetry software.
The past and present advantages and disadvantages of small aerial platforms are also considered, together with some of the emerging technologies and recent developments. Examples of monitoring and mapping macro-algal weed mats and coastal shorelines are used to illustrate the potential of today's small UAV platforms and the accompanying sensors to acquire low-cost airborne data and imagery.