It is a known fact that solar flare can affect and disrupt GPS ( and other ) satellites and their signal.

In May 2013 NASA reported the most active solar flares of the sun cycle, which began in 2008 and will last until 2019. Four high-strength flares occurred May 13 into May 14.

"Basically, this is as busy as the Sun has been in a 24-36 hour period since 2004," said Astronomer Mark Paquette. Paquette used information researched by Daniel Vogler, co-director of the AccuWeather Astronomy Facebook page.

Using data dating back to 1992, Paquette found only one other instance with as much sunspot activity in such a short amount of time.

"Sunspot AR649, July 15-17, 2004, unleashed five X[-strength] flares," he said. "So what we are witnessing with sunspot AR1748 is pretty rare."

Solar flares are measured on a scale of intensity ranging from A, B, M, C to X. The X-strength flares, the level the recent solar activity has been categorized as, are the highest strength.

The sun has fired a second massive solar storm in two days directly towards the Earth on August 23 2013.

As it nears 'Solar Maximum', the regular period in which solar activity is most intense, it is more likely that Earth will come under bombardment from billions of tons of charged particles.

But NASA says
that the attacks do not represent a threat to humans.

The eruption - a Coronal Mass Ejection - sent particles towards Earth at 280 miles a second yesterday morning, at about 6 am UK time. It will reach Earth sometime over the weekend ( August 23-26) , NASA said.

"These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground," NASA said in a statement.

"Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth's magnetic envelope, the magnetosphere, for an extended period of time." reported that the CMEs are expected to hit Earth on August 23 and 24, and warned that geomagnetic storms could be sparked around the poles.

This can have disruptive effect on all satellite communication , including GPS systems.