In a posting on its Project Loon Google+ page, the Project Loon team said last week that it has been busy conducting a series of research flights in California's Central Valley.
The team reported that “On our most recent research flight we overflew Fresno, a nearby city, to get statistics on how the presence of lots of other radio signals (signal-noise) in cities affects our ability to transmit Internet. It turns out that providing Internet access to a busy city is hard because there are already many other radio signals around, and the balloons’ antennas pick up a lot of that extra noise. This increases the error-rate in decoding the Loon signal, so the signal has to be transmitted multiple times, decreasing the effective bandwidth.”
The purpose of the test flights is to evaluate difference approaches for improving the technology in areas such as power systems (solar panel orientation and battery), envelope design, and radio configuration. The team said the tests over Fresno will help them understand how signals and noise interfere with the signals from the balloon so they can determine the signal strength needed to communicate effectively.