GPS: From launch to everyday life

The GPS Block II satellite - the type launched in 1989

Many people use GPS to stop them getting lost and help them reach their final destination when on a journey.

For drivers it's replaced maps as the easiest way to navigate, but it is not just useful for mapping and tracking - GPS is now being used in many different areas of life and sometimes with unexpected consequences.

Originally used for military purposes, it was decided by US President Ronald Reagan that GPS should be made available for civilian use and in February 1989 the first Block II satellite was launched.

Twenty-five years after the launch of the system we use today, people are now using GPS in ways that few could have predicted at the time.

You have reached your destination

Following GPS may lead you to somewhere unexpected

Finding your way from one end of a country to the other used to require at least one very large map, if not a multitude of small ones.

But when the US government changed the rules allowing greater accuracy of satellite signals to be available to non-military users, the boom in GPS navigation devices for cars started.

The dulcet female tones directing you to "take the next left" or telling you that "in 200 yards you have reached your destination" became a common sound on car journeys.

Although the GPS signal was more accurate, it still led to some some drivers finding themselves in precarious situations.

In 2009, Robert Jones followed his satnav down a path in West Yorkshire that ended with his car hanging off the end of a cliff.

Three Japanese tourists on holiday in Australia in 2012 found themselves floating rather than driving after their GPS system tried to send them across water to reach an island.

In cities around the world it is now a common sight to see pedestrians with their head bowed over a smartphone as they track themselves on a map trying to work out where they are going.

Twenty-five years on, one of the creators of GPS, Professor Brad Parkinson, told the BBC that despite inventing the system he still preferred to use maps to find his way around.

"Most people don't pull out maps anymore, they pull out smartphones, and then tend to blame GPS if the directions are wrong," said Professor Parkinson.

'Here kitty-kitty'

Monitoring cats movement found many of them simply went next door

GPS has been used to understand the movement and behaviour of different groups of animals.

The theory that sheep try to get to the centre of a flock if threatened by a predator was tested by using GPS devices attached to the animals, and cow bells were swapped for GPS collars on a herd in Northumberland to work out how cattle grazed in their local area.

Injured hedgehogs were fitted with their own GPS backpacks when they were released back in to the wild so conservation experts could examine how they went on to survive in an attempt to boost survival rates.

The secret life of domestic cats was exposed for the first time after The Royal Veterinary College teamed up with the BBC's Horizon programme to track the movement of felines via a GPS tag. The findings revealed that when owners thought their cats were out prowling the neighbourhood gardens, they were in fact sneaking in to other cat owners' houses to eat the food.

Where have you been?

Suspicious partners may use GPS

Parents worried about their children can now track where they are using GPS devices. Tags that attach to bags or clothing, wrist bands that can be worn or apps that can be accessed on smartphones can all be used to monitor movement.

While mums and dads can openly check on their children, they may also be using GPS to covertly check on each other's movements.

A husband allegedly caught his wife cheating after tracking her to a different place in New York from where she claimed to be by using the GPS function on her mobile phone.

"Are there serious infringements of privacy?" said Professor Parkinson.

"I'm certain there are lots of instances where a husband is tracking a spouse that end up at the threshold of 'maybe that's a little too much' but wanting to know where a child is? That's a legitimate tracking application in my opinion," he said.

The perfect shot

It's there somewhere

Wading through the undergrowth trying to find a golf ball that somehow managed to find its way off the green is no golfer's favourite activity.

But golf balls which contain a small GPS chip have now reduced this hide-and-seek element of the game. Some versions also have an audio device which gets louder as you approach it. The satellites in the sky have allowed the most hapless of sportsmen to speed up his game.

Professional footballers are also using GPS to improve their game. Top flight teams including Manchester City and Liverpool are using GPS monitors during training sessions to track players' speed, distance covered and heart rate.

If hasn't yet been used to guide a footballer's strike goalwards, old-fashioned skill is still the preferred method for scoring.

Bullets in the boot

Catching criminals in some US states became easier after police forces there started to use GPS bullets in 2013.

GPS has helped police in the US cut down on car chases

Chasing culprits who had escaped in a car used to be a dangerous business but with one press of a button a bullet inside the car is launched that attaches itself to the car in front without the driver even knowing.

The police can then call off the chase and track the vehicle using the GPS data, waiting patiently to see where the trail takes them.

It's a high-tech solution to foil an old-fashioned escape, and a new way to keep using GPS in to the future.