Learning to use a GPS unit
First they had to calibrate the GPS by sitting it outside to find satellites. The GPS units work best under clear skies because they have to send and receive radio signals from satellites miles above the earth. The signals are blocked by clouds, trees, tall buildings and mountains. But Barnaby found he was getting a reading even at the kitchen table because of the house being on a hill and having big windows!
Then they practiced online with a Geocaching simulatorĀ andĀ found a cache in Sweden!
Coordinates for caches are usually in WGS84 format (World Geodetic System 1984 ) which is a little bit different to the latitude and longitude format used on maps. The GPS knows several formats Online converting tool
They hid Barnaby around the garden by using the ‘mark’ button to show their latitide and longitude and entering a a label for his ‘waypoint’. To find him again they used the ‘go to’ button and selected the saved waypoint from a list. A little compass needle showed them when they were heading towards the right spot. The GPS compass works only when you are walking. A regular compass likes you to stand still! The GPS kept a track of where they walked which looked like a dizzy ant trail!
- Then they chose a team name
- signed up to a few websites www.geocaching.com and www.geocaching.com.au,
- chose some caches for their trip,
- printed the hints,
- entered the coordinates into the GPS
- packed a small bag with gloves, spare batteries and some little things to swap for the treasure and set off!




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