Get Used to Smaller Lighter High-performance GPS Units
but With Fewer Navigational Functions
The new generation of “performance measurement GPS” units have exceptional electronics and GPS performance. They are small, light and wearable but have minimal navigation functions. Left: the Garmin Edge 305, actually a bike unit but similar in weight and smaller than a Geko- it should work for a handheld backpacking GPS. Right: the wrist-wearable Garmin Forerunner 305. Both have barometric altimeters and heart rate monitors.
GPS manufacturers continue to focus their innovation and marketing in two areas,
1) Large-screened mapping units with full navigational functions [eg. the Garmin GPSMAP 60 and 76 series] around 8 oz, and
2) Small “performance measurement GPS”, usually wearable, but with small screens, no mapping capabilities and minimal navigational functions [Suunto X9i, Garmin Fore Runner 205 and 305; and Edge 205 and 305] around 3 oz
Why is this important to lightweight backpacking? Well, our core lightweight, navigationally focused units are languishing in the technological dust. The Geko 101 is discontinued and who knows how long until the Geko 201 and 301 fall into the tar pit of extinction? Neither the Geko or the eTrex units are slated to have the newest SiRF III GPS Engine. If you want to a good GPS fix in tree cover or in a tight canyon, you need SiRF III GPS or a similar digital GPS signal processor. [The new digital processing of the SiRF chipset has many thousands of times more signal processing power than traditional 12 channel analog GPS receivers. This means amazing performance like full time GPS tracking in a deep canyon of redwood trees.]
I’m deeply disappointed that improved mapping and GPS performance will not make it into the e-Trex and Geko series. Even just some better navigational features into the Forerunner or Edge series would be nice. Garmin are you listening?
While I laud the improvements to the larger mapping units (I use a Garmin 76CSx for my kayaking expeditions and love it to pieces), at almost 8 oz I wouldn’t consider them for a backpacking trip.
For the time being if I want the latest and greatest in lightweight GPS electronics for backpacking I need to make peace with the limited navigational features of the new small performance measurement GPS (SPM-GPS) like the Garmin Fore Runner 305.
Over the next few months I will be testing the applicability of small performance measurement GPS to lightweight backpacking. Hopefully we can come up with a How To/Tips and Tricks piece to use SPM-GPS for lightweight backpacking.
New SPM-GPS units have tight integration with performance analysis software and electronic mapping like Google Earth. Example above is Garmin Training Center™ software. Below is the web-based application Motion Based™ that integrates with Edge and Forerunner data for performance tracking and mapping.
Advantages of small performance measurement GPS (SPM-GPS)
- Sophisticated digital GPS circuitry captures weak signals in difficult reception areas like tree cover and narrow canyons or a combination of both!
- Small wearable size (or in the case of the Garmin Edge small and mountable)
- Potentially lighter weights (currently the same weight as the lightest units)
- Tight integration with performance analysis software and with electronic mapping like Google Earth
- Rechargeable batteries
- Many monitor heart rate
Web-based application, Motion Based™, that integrates with Edge and Forerunner data for performance tracking and mapping.
Disadvantages of small performance measurement GPS (SPM-GPS)
- Limited navigational functions (usually just 50-100 waypoints)
- No mapping
- Limited Battery life (non-field replaceable batteries = approx 10 hours) although there are ways to recharge these units in the field with user-hack battery packs attached to a micro-USB cable
- Even smaller screens
How to deal with the limited navigation features SPM-GPS
- Even though SPM-GPS data transfer definitions aren’t available in most mapping software like Nat Geo Topo! theoretically data transfer a should work by selecting a basic GPS unit like a Garmin 201 (National Geo Topo! already has a definition for the Suunto X9 units)
- Also to transfer data you’ll need to load a USB/GPS driver
- In lieu of on-screen GPS mapping, use custom printed maps with waypoint labels and download the waypoints to your SPM-GPS. For more info on this refer to Backpacking Light’s article Guide to Selecting and Using Ultralight GPS Systems http://www.backpackinglight.com/cgi-bin/backpackinglight/ultralight_gps_guide_04.html