Global science project links Android phones to satellites to improve weather forecasting

Collecting satellite data for research is a group effort through this app developed for Android users. Camaliot is a campaign funded by the European Space Agency, and its first project aims to engage smartphone owners around the world in a project that can help improve weather forecasts using your phone’s GPS receiver.

The Camaliot app works on devices running Android version 7.0 or later that support satellite navigation. As satellite navigation works, phones or other receivers search for signals from a network of satellites that maintain a fixed orbit. Satellites send messages with the time and location, and once they are received, phones note how long each message took to arrive, then use that data to determine where they are on Earth.

Researchers think they can use satellite signals to get more information about the atmosphere. For example, the amount of water vapor in the atmosphere can affect how a satellite signal travels through the air to something like a phone.

The app collects information to track signal strength, the distance between the satellite and the phone being used, and the carrier phase of the satellite, according to Camaliot’s FAQ. With enough data collected from around the world, researchers can theoretically combine this with existing weather records to measure long-term water vapor trends. They hope use this data to inform weather forecasting models with machine learning. They can also track changes in Earth’s ionosphere – the part of the atmosphere close to space. Creating better ionospheric forecasts could be relevant for tracking space weather and could eventually make global navigation satellite systems (GNSS) more accurate in accounting for events such as geomagnetic storms.

Camaliot could eventually expand to include more attempts at large-scale data collection using sensors found in “Internet of Things” connected home devices. “We were inspired by the famous [email protected] initiative, where home laptops help search for signs of extraterrestrial life.” Vicente Navarro, an ESA navigation engineer, said in a press release.

App users can compare their measurements to other Android users
Image: Camaliot

The project aims to gather information from around the world – and from several different satellite constellations. There are several different constellations of global navigation satellite systems (GNSS), such as the American Global Positioning System (GPS), the Russian GLONASS, the Chinese Beidou or the European Galileo. Japan and India also operate smaller regional constellations. An FCC order in 2018 allowed more devices to use GPS and Galileo signals together for increased location accuracy.

While older Android phones can participate in this project, the Camaliot project lists more than 50 newer models with dual-frequency receivers, which can pull two GNSS signals with different satellite frequencies simultaneously. Phones confirmed to contain dual-frequency receivers include the Google Pixel 4a, Samsung Galaxy S21, Galaxy S21 Ultra – mostly those with high-end Qualcomm Snapdragon 5G chipsets.

Navarro says “the combination of Galileo dual-band smartphone receivers and Android’s support for logging raw GNSS data” work together to increase the possibility of how much data can be collected just from people using their smartphones.

Camaliot is only available for Android users
Image: Camaliot

The use of in-home technology by outside participants for scientific exploration continues to grow as everyday devices include more processing power and better detection capability. Besides the famous SETI project and similar attempts like [email protected], other methods have included NASA asking the public to use their phones to take photos of clouds or trees, and science apps like iNaturalist documenting the behavior of animals during a solar eclipse, or following different animal species.

How to use Camaliot

Here is how you can start using the Camaliot app on your Android phone after downloading it from Google Play:

  1. Select “Start Recording” and place your phone in an area with a clear view of the sky to begin recording data
  2. Once you’ve measured to your liking, select “stop logging”
  3. Then upload your session to the server and repeat the process over time to collect more data. You can also delete your locally stored log files at this step.

In addition to being able to view your own metrics against others accumulated over time, you can also see a leaderboard showing recording sessions performed by other participants. Eventually, the information collected for the study will be available on a separate portal.

For registered users, their password, username, email address and number of measurements will be stored in Camaliot’s database, but they will not be used in post-study publications and products, in accordance with Camaliot’s privacy policy. Specifically, Camaliot asserts that the need for extensive personal data is for scientific and environmental monitoring purposes and that its need for data processing is “necessary for the performance of a task carried out in the public interest, namely for the conduct of this scientific study. ”

Registered participants will also be entered into a pool for a chance to win prizes such as a dual frequency Android phone and Amazon vouchers. The campaign will be active until June 30.