For 25 years, GPS satellites have been circling the planet, providing radio signals that can be used for navigation and tracking. Now a company plans to tap the network, as well as three other similar global satellite systems, to make real-time weather forecasts.
The company, called PlanetiQ, is designing a constellation of 12 to 18 small satellites that will keep watch as the GPS spacecraft pass through Earth's orbital horizon.
Measuring how the GPS radio waves bend as they travel through the atmosphere can provide snapshots of temperature, pressure and water vapor, as well as insight into whether solar storms are kicking up the ionosphere.
Data collected through this technique, called radio occultation, will supplement computer models to produce more accurate and timely weather forecasts and assessments.
"For severe weather events and space weather prediction, time really is of the essence," Karen Dacres, general counsel for Maryland-based PlanetiQ said at the Federal Aviation Administration's Commercial Space Transportation conference last week.
In addition to monitoring GPS signals, PlanetiQ's orbital network will pick up radio transmissions from Russia's GLONASS, Europe's Galileo and China's Beidou satellite systems, resulting in more than 30,000 occultation measurements per day.
"Data quality is very important because poor data will actually degrade the forecast, rather than improve it," Dacres said.
PlanetiQ is one of five companies in the United States looking to commercialize weather forecasting, following in the paths of satellite communications and Earth remote sensing.
"History has repeatedly shown advances often come from applications that were never considered in the first place and emerge only after the technology is developed," said Paul Damphousse, founder of General Astronautics, a Washington DC-based consulting firm.
PlanetiQ intends to have its commercial weather satellite network in orbit by 2017. GeoOptics, based in Pasadena, Calif., is working on a similar system, with launch of its first satellite targeted for this year.
"Weather data commercialization really is at a tipping point. A transformation is occurring in the business of weather and part of that is driven by ... a growing commercial demand for data," Dacres said.
For example, in 2013, agrochemical company Monsanto paid nearly $1 billion for the Climate Corporation, which produces apps of field-level weather, soil and crop data.
"Everyone understands that while we can't control the weather, we can certainly help to manage the financial implications of what weather can do," Dacres said.