A Grassroots Remote Sensing Toolkit Using Live Coding, Smartphones, Kites and Lightweight Drones

Abstract

This manuscript describes the development of an android-based smartphone application for capturing aerial photographs and spatial metadata automatically, for use in grassroots 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).

Species and habitat mapping in two dimensions and beyond. Structure-from-Motion Multi-View Stereo photogrammetry for the Conservation Community

“…They can be utilised to create highly detailed maps and 2.5/3D data at local scales, now include FOSS options that are being successfully deployed for scientific research (3,4,53–58,62,105) and can be incorporated into the existing FOSS remote sensing pipeline. With applications for Android smartphones such as the UAV Toolkit (67) or small, lightweight action cameras now available, combined with balloons, kites, drones, or even collecting data on the ground, there is an opportunity within the conservation sphere to start enabling remote sensing even at a grass-roots or community level, or in any situation where funding may be limited but this type of data desired. In support of the conclusion presented by Berger-Tal and Lahoz-Monfort (49), SfM-MVS as part of a FOSS remote sensing pipeline is one such technology that can help the Conservation industry innovate and dismantle the neo-liberal conservation paradigm.…”

“…once every 2 seconds – will simplify data collection. Android apps such as DroneLab Toolkit (67) can also help by providing an intervalometer to cameras in Android phones along with other useful mapping tools. Use GCPs – Unless using a camera system or drone equipped with an RTK/PPK (real time or post processing kinematic) GNSS that automatically adds high precision location data into images, the simplest way to adequately warp your model geospatially, is to use GCPs marked using a handheld GNSS (68). For higher accuracy and precision, a DGPS (differential global positioning system) or an RTK/PPK system will be required but can be cost prohibitive.…”

“…once every 2 seconds – will simplify data collection. Android apps such as DroneLab Toolkit (67) can also help by providing an intervalometer to cameras in Android phones along with other useful mapping tools.…”

A UK Civil Aviation Authority (CAA)-approved operations manual for safe deployment of lightweight drones in research

“…Puttock et al 2015e.g. Puttock et al , 2017Carbonneau and Dietrich 2016;Anderson et al 2016). Increasingly, academic researchers utilizing RPAS may deem it necessary to obtain permission from the CAA, codifying their operational competence, in order to (i) comply with institutional insurance requirements (Lloyd's.…”

Remote Sensing for Irrigation of Horticultural Crops

“…Anderson et al [93] also proposed a grassroots remote sensing and democratic mapping for delivering rapid spatial data (GeoTIFF images) from lightweight drones and kites with open-source geospatial toolkits and android smartphone apps.…”