GPS Equipment

The purpose of this page it to describe the various types of GPS units, show which are most suited to orienteering and to give an idea of their price.

Types of GPS Units

There are many different typed of GPS receivers. Some are more suitable for orienteering than others:

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• Satnav This is what you have in your car. It displays a map on a screen, several inches across. You can even get it to tell you which way to go. Unfortunately, this is not suitable for orienteering. eg. Garmin Nüvi
• Bluetooth Receiver This is a plastic box, a little bigger than a match box. You can connect this to a PC, PDA or even a mobile phone, using a bluetooth connection. Basically, you need another device to record your track. eg. Holux M1000
• GPS Logger This is similar to the Bluetooth Receiver except it will record your track itself. You can then download your track to a PC later. These are popular to geo-tag photographs. One of these would be a good low-cost way of recording your track while orienteering. eg Holux M241
• Fitness Recorder These are specially designed for running or cycling. As well as recording your track, they will display various information eg. speed, distance traveled, heart rate. Many will take split times. Most are perfect for orienteering, though cycle-specific ones may be a bit too large. eg. Garmin Forerunner 305
• Handheld These are the “classic” GPS devices. They have a small screen and may be able to display your position on a map. They have all the normal GPS features (record tracks, record waypoints, display routes) but usually do not provide the sport data of the Fitness Recorders. A bit bulky for orienteering. eg. Garmin eTrex

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Assisted GPS

Each time you turn on your GPS unit, you may have to leave it for several minutes before it gets initial satellite lock. During this time, you should not move the unit and it should be in a good reception area (clear view of the southern horizon and no tall buildings). This can be a problem in some situations (eg. satnav). To improve on this, GPS manufacturers have come up with Assisted GPS (AGPS). This allows you to pre-load the GPS unit with some of the data that it needs. This an make it quicker and easier to lock on to the satellites. Having used the internal GPS on an XDA Orbit, I did not find that it locked onto the satellites much quicker, however it was able to get lock while I was moving. This can be a major advantage.

There are two “generations” of AGPS:

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• For a Generation 1 unit, you download an ephemeris from the manufactures web site and load it onto the unit. This takes a few seconds and is good for up to 6 or 7 days. The disadvantage is that you need an internet connection every few days.
• A Generation 2 unit calculates an ephemeris itself. This means that you don’t need an internet connection. However, it takes 24 hours for the unit to generate the ephemeris and it is only good for 3-4 days.

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If you are in the market for a GPS unit, you may find it useful to get one with AGPS.

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Models and Prices

A quick trawl of ebay.ie gives the following prices for GPS receivers which might be useful for orienteering. I have included the best prices from European sellers (usually UK) and the USA and aspidshop.com. With some research, you may find them cheaper elsewhere. The USA sellers are usually cheaper but there may be an issue with duty and you may prefer a local seller. Prices include p&p (€ 18 for aspidshop.com).

As of August 2008