BUSHWALKERS WILDERNESS RESCUE SQUAD ^INC.

A volunteer group of experienced outdoors people.

Bush Safety - GPS (Global Position Indicators)

GPS - for Bushwalkers

The Global Positioning System does not replace map and compass for navigation in the bush but it is an excellent additional tool.  It can speed up decision making and reduce the need for time consuming backtracking although you will still be wise to keep check of terrain features.  Route-finding, map reading, map to ground and compass skills are still very important skills.

The present-day hand held gps receivers do not work in the following circumstances: -

• under heavy vegetation cover,
• in heavy rain/snow precipitation conditions,
• under wet foliage,
• in steep valleys or canyons,
• under-cover,
• with a dud battery.

A gps works best in the open or on high ground, where the antena has a clear 360 degree view of the sky.

Keith Maxwell advises the following website for information on latest gps receivers

Garmin GPS.

At the top end of the Garmin range of GPS receivers are some new models with improved sensitivity compared with existing models. 

GPS technology is constantly changing. The Garmin eTrex and Geko models are good GPS receivers for bushwalkers being comparatively low cost, lightweight and easy to use. Other manufacturers also can supply similar simple, light-weight GPS receivers.

However the new Garmin 60x and 76x series GPS are larger, more advanced but more expensive. These GPS receivers are more sensitive than the eTrex and Geko models but start at over $480 in the USA. They have the "SIRF Star 3" chipset. The link below is a Garmin press release for these 60x and 76x series GPS.  http://www.garmin.com/pressroom/outdoor/010306b.html

A member of BWRS recently did a comparison test between an eTrex and 60x series GPS receiver and found that the 60x was far superior in maintaining satellite lock within a closed canopy of trees. The eTrex often lost satellite lock (a GPS receiver needs to "lock" onto a minimum of four satellites to get a three dimensional location (no lock = no location)) while the 60x maintained satellite lock.

Some other Garmin GPS receivers getting this "SIRF" technology include Forerunner 205 and 305; Edge 305. To be sure of getting this new technology look for the "SIRF" logo on product information.

Naturally, other manufactures are including the SIRF Star 3 chipset in their GPS (and getting rave reviews). Thus it is highly probable that this improved technology will continue to filter down to lesser model GPS receivers.