ESA challenged its young graduate and national trainees to develop a smartphone app to perform satnav fixes using only Galileo satellites. Three teams developed apps in their spare time, presenting their results to a jury of experts from ESA, the European Global Navigation Satellite Systems Agency (GSA) and Google.
“I’m very impressed,” said Javier Benedicto, ESA’s Galileo programme manager. “With little detailed knowledge of satellite navigation, these teams have developed something that didn’t exist just a few months ago. Working on Galileo we love to see that the systems we’re putting together can reach widespread application and inspire new uses.”
The winning Galfins Team put together the GNSS Compare app that promises to turn a smartphone into a ‘research lab in your pocket’, to test Galileo performance in isolation or in combination with other systems. Their prize is to attend an ESA and European Commission-sponsored GNSS Summer School in Austria.
App competition winners
Mateusz Kraiński of the Galfins explained: “Only one of our four-strong team started the challenge with any knowledge about satellite navigation. The rest of us come from different areas – for example, I’m working on the European Robotic Arm project, due to launch at the end of next year. We have learnt a lot and the radio navigation experts at ESTEC were a great source of support.”
“We see a need on the market for such an application, so we will definitely continue with the development. The application will be made available for download when ready, and the project will be released as open source soon after.”
The other two teams were also commended for their work; Chocolateam developed a richly-designed game-based app, giving the user the feeling of observing the Galileo satellites from a spacecraft, while Team 5G distinguished themselves by writing all their own navigation algorithms from scratch rather than relying on open source software.
The challenge was to design an Android smartphone app that allows users to compute and visualise their position based solely on Galileo measurements, as well as the possibility of selecting a combination of satnav constellations to assess their performance.
The receiver chipsets inside smartphones make use of Galileo signals in combination with several other satnav constellations – the US GPS, Russian Glonass and Chinese BeiDou. These chipsets function like ‘black boxes’, making the resulting positioning fix accessible to users, but not giving any option for the user to select which constellation to employ.
Current phone applications only display general satnav status information, such as which satellites are contributing to the positioning fix, their visibility parameters and overall power levels. This is not sufficient to single out Galileo’s contribution to the phone’s overall positioning performance.
However, in newer Android smartphones it has become possible to access the raw signal measurements used to compute position, opening the door to the development of applications where the user can indeed select which satellites to use.
The teams received one Galileo-enabled smartphone each for developing and testing the app.
ESA’s Directorate of Technology, Engineering and Quality supported the teams by supplying dedicated software modules to simplify computations of the phone position. During the competition, a technical advisory team also developed an internal app as a benchmark. The app, named Galileo PVT and developed by ESTEC engineers Paolo Crosta and Tim Watterton, includes an augmented reality system allowing users to ‘see’ the Galileo satellites from which they were receiving signals in the local sky.
“This was a very useful exercise because it helps us understand the needs of satnav app developers in Android,” said the lead advisor, Paolo Crosta.
“Then, once the apps were complete, we tested them together, here on the grounds of ESTEC, working in stationary, pedestrian and vehicular modes.”
Pedestrian testing
“Congratulations to all the teams here today,” commented Frank Van Diggelen from Google, who had just come from a satnav raw measurements workshop hosted by the GSA. “It’s been great to be here and see all the activity around raw signal measurements.
“Our aim has always been to raise standards by making these measurements available, to let developers see what’s happening inside. And the work you’re doing here is feeding back to chip and smartphone manufacturers, to help change and improve them for the future.”