App to convert smartphone into remote-sensing device

Researchers from University of Exeter have created an app which can help aid humanitarian rescue work in disaster-struck regions by using geographic data to map landscapes.

The android app can convert smartphone into a self-contained remote sensing device.

The app, created by University of Exeter scientists and collaborators from the Cornwall-based non-profit FoAM Kernow, uses on-board sensors already within modern smartphones.

These include accelerometer, GPS, compass and camera and generate ready-to-use spatial data when the device is suspended from lightweight aerial platforms such as drones or kites.

The app gathers the data and allows the smartphone to operate autonomously so that once airborne, it can capture images according to the user's specification.

"There are now more mobile devices than humans on Earth. This global distribution of devices offers a great opportunity for democratic mapping but until now, there have been no apps that exploit the comprehensive sensor sets in modern devices in this way," said Dr Karen Anderson, remote-sensing scientist at University of Exeter.

Currently the sensors on mobile phones harvest data about their users and send this information to third-parties.

"We wanted to start using this data for beneficial purposes such as community-led mapping. Alongside recent developments with lightweight drones, we are excited to see the variety of mapping applications for which our new app will be used," Dr Anderson noted.

The app is different from many other apps because it can be "live-coded" which means that it is not fixed in its functionality.

This allows the user to programme it to behave as desired and images can be captured according to strict criteria for example, when the phone arrives at a particular location, or when the camera is level and pointing in a particular direction.

Dave Griffiths, Director at FoAM Kernow, who programmed the app, said: "As free/open source software, the app is accessible to anyone in the world with an android device.

It means that people can combine new sensor technology for their own uses with drones or kites in an open-ended manner.

The team found that the best results were obtained when the phone was attached to a stable single line kite or to a gliding drone so as to limit the vibrations.

"But there will undoubtedly be a wide range of ways of capturing high-quality data using this app and we are really keen to learn about the ways it is being used," the authors added.

The app can be freely downloaded from the Google store. All of the code that supports generation of Geo-TIFFs is freely available from GitHub.

The paper was published in the journal PLOS ONE.

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