Baby-sitting via satellite

Satellite technology is being used in the US to keep track of children and offer peace of mind to parents.

A wristwatch containing miniature Global Positioning System (GPS) technology has just gone on sale.

The GPS Personal Locator developed by Silicon Valley company Wherify Wireless uses advances in satellite tracking and wireless technologies to allow parents to find their child within a minute.

The hope is that a device like this one could act as either a deterrent to potential kidnappers, or at least aid police investigating a missing child case.

Panic button

The GPS Personal Locator allows parents to track a child's location and movements via the internet.

"Let's say you have a seven-year-old who walks to school alone and they felt in danger. They could push one button on the watch and lock the device," said Wherify President Timothy Neher.

"It will enable a consumer to locate this device, initially in the US, within 60 seconds or less," he told the BBC programme Go Digital.

Designed around a wristwatch, the locator has a built-in pager and panic button for alerting the police.

The device uses the same GPS technology that helps lost drivers or sailors find their way.

'Cool factor'

The device is aimed at children between the ages of four and 12.

"Kids think this watch is cool," said Mr Neher.

"It's their first communication device, it's a watch, it's a pager, its a locator. There's a cool factor from what we are hearing from the children."

Parents can use the internet or phone to quickly identify their children's location within feet in about a minute.

They are also able to constantly track a child 24 hours a day either by logging onto a computer and viewing aerial maps, or by calling Wherify's location centre.

"If I had my five-year-old in downtown New York City at Christmas time, I want to just lock this on them and then when we are done shopping take it off," said Mr Neher.

In the US, a child is reported missing every 42 seconds, according to official statistics. But Mr Neher denied his company are trading on parents' fears.

"I don't think we are selling the fear, I think we are giving parents peace of mind," he said.

Innovative uses

All this technology does not come cheap. Wherify's GPS Personal Locator for Children has just gone on sale at a price of US$399.99, plus a monthly service charge of $25.

It is currently only available in the US although the company are developing a GSM model which could be used in the UK.

Originally GPS receiver modules were large and bulky. But today the modules can be as small as a thumbnail.

As GPS units shrink in size, more innovative uses of the technology will develop, say experts.

Golf courses are already outfitting carts with GPS to help players measure distances between shots, car manufacturers are offering in-dash navigation and farmers are using the technology for precision mapping of crop yields.