| As scary as it may be, the US Department of | | | | One great appeal of many portable GPPS devices |
| Defense has been using satellite technology to | | | | is their multi-functionality. A wristwatch with GPS |
| track the location of targets anywhere on Earth | | | | capability, for example, is a great tool for those |
| with pinpoint accuracy for the last thirty years. | | | | who enjoy outdoor pursuits like hiking, fishing, and |
| GPS, or Global Positioning System technology, lets | | | | camping; it eliminates the need for inconvenient |
| GPS portable receivers pick up transmissions from | | | | maps. Having a GPS portable device in your PDA |
| four of the twenty-four tracking satellites. | | | | will be a great way to help you find your way |
| By interpolating the data from the four satellites, | | | | around strange cities or find alternate routes |
| GPS portable receivers are able to get a very | | | | when traffic is moving against you. |
| clear picture of their own longitude and latitude, as | | | | The Garmin handheld GPSMAP 60CSx uses the |
| well as the correct time. To be able to function | | | | state-of-the-art SiRFstar III chip to give it a |
| properly, however, the GPS portable receiver | | | | nearly instant link--usually less than thirty |
| must be positioned where it the satellite | | | | seconds--to satellite transmissions even under |
| transmissions will not be blocked. | | | | heavy vegetation or in canyons. It is ideal for |
| Sometimes a difference of a few feet can mean | | | | back country mapping and also has optional |
| the difference between a clear signal to the GPS | | | | software to provide turn by turn directions and |
| portable receiver, and a weak or blocked one. | | | | automatic routing.Listing for $536. it can be found |
| The GPS portable receivers are often incapable of | | | | on the Internet for $350. |
| receiving signals if they are being used near tall | | | | The Garmin iQue 3600 PDA with GPS capabability, |
| buildings or under heavy canopies of vegetation. | | | | first introduced in 2003 with a sticker price of |
| The GPS portable receivers can be used indoors, | | | | $589 is now advertised on the Internet for as |
| but only with the aid of an external antenna. | | | | low as $339. |
| Commercial GPS portable devices are now | | | | Finally, the Garmin GPS Forerunner watch for |
| available in an amazing variety of applications | | | | runners, although they are far from elegant, is a |
| besides stand alone receivers. They are | | | | waterproof training devise with technology which |
| incorporated into PDAs, wristwatches, and cell | | | | enable it to pick up satellite transmissions even |
| phones. And of course, there are portable GPS | | | | among tall buildings or under heavy vegetation. |
| receivers for automobiles, motorcycles, and boats. | | | | These GPS watches can track distance and time |
| Features And Prices Of GPS Devices | | | | and run about $240. |