02.What to look for
When choosing a handheld GPS, these are some of the things you should look for.
- A high-resolution and preferably colour screen is necessary if you want to use detailed topographical maps.
- The unit needs to be comfortable in your hand, with well-spaced buttons that allow you to select functions more easily.
A battery compartment that accepts standard batteries (AA or AAA) means you can use either rechargeable or normal alkalines in an emergency.
- PC mapping software allows you to select a waypoint or route at home and download it to your GPS to use in the field.
A connectivity cable allows your GPS to connect to a PC to download and upload information. But beware — these cables can be expensive if they use a proprietary connection.
Google Earth (http://earth.google.com) accepts latitude and longitude figures to zoom straight to any spot on earth. So you can just enter stored waypoints from your handheld GPS to show lucky friends spots along your last trek.
Some products provide the option to take the experience further; Google Earth Plus (annual subscription $20) allows you to export tracks from your GPS onto Google Earth, such as a treacherous ravine crossing in Kosciusko National park or a perhaps even more treacherous literary pub crawl in Dublin. Connect your unit to the PC, upload your route information and the complete journey will be shown on a Google Earth map for all to see.
Did you know?
Soon after it was created, the civilian GPS was doctored by the US government, which incorporated an artificial inaccuracy (up to 100m) to counter any potential terrorist threat. Bill Clinton removed this restriction in 2000, arguing that the public good to be gained through using as accurate a system as possible would outweigh any security concerns.
However, the US government still reserves the right to introduce selective availability if it feels its national interests are threatened, for example, during the war in Iraq where the civilian GPS was made inoperable within the war zone.
Fix: A successful connection with a group of orbiting satellite.
GPS: Global Positioning System.
Topographic map: Shows elevation through the use of contour lines and altitude markings.
Waypoint or POI (point of interest): An exact co-ordinate marked to show a position.