A grassroots remote sensing toolkit using live coding, smartphones, kites and lightweight drones
Shutler, Jamie D.
Public Library of Science (PLoS)
This is the author accepted manuscript. The final version is available from PLoS via the DOI in this record.
This paper describes the development of an android-based smartphone application aimed at capturing automatically triggered aerial photographs for grass-roots mapping applications. The aim of the project was to exploit the plethora of on-board sensors within modern smartphones (accelerometer, GPS, compass, camera) to generate ready-to-use spatial data from lightweight aerial platforms such as drones or kites. A visual coding 'scheme blocks' framework was used to build the application ('app'), so that users could customise their own data capture tools in the field. The paper reports on the coding framework, then shows the results of test flights from kites and lightweight drones and finally shows how open-source geospatial toolkits were used to generate geographical information system (GIS)-ready GeoTIFF images from the metadata stored by the app. Two Android smartphones were used in testing - a high specification OnePlus One handset and a lower cost Acer Liquid Z3 handset, to test the operational limits of the app on phones with different sensor sets. We demonstrate that best results were obtained when the phone was attached to a stable single line kite or to a gliding drone. Results show that engine or motor vibrations from powered aircraft required dampening to ensure capture of high quality images. We demonstrate how the products generated from the open-source processing workflow are easily used in GIS. The app can be downloaded freely from the Google store by searching for 'UAV toolkit' (UAV toolkit 2016), and used wherever an Android smartphone and aerial platform are available to deliver rapid spatial data (e.g. in supporting decision-making in humanitarian disaster-relief zones, in teaching or for grassroots remote sensing and democratic mapping).
Funding for the project to develop and test the app was provided by the European Social Fund to Dr Karen Anderson and Dave Griffiths. The aircraft and kite systems used were from the Environment and Sustainability Institute DroneLab at the University of Exeter, which Karen Anderson leads. We are grateful to Colin Anderson, Polly Shutler and Oscar Griffiths for assistance in the field.
PLoS One, 2016, 11(5): e0151564