glonass

Satellite pages from a Garmin GPSMap 66s showing the GPS and GLONASS status screens

The GPSMap 66 series are the first trail receivers from Garmin to use both the Russian GLONASS and European Galileo satellite navigation systems. On the Satellite Setup page, you have a choice of using GPS (NavStar) only, or GPS+GLONASS, or GPS+Galileo. The advantage of using Galileo or GLONASS with GPS is that you have more satellites in the sky, which improves the quality of your position fix, and increases the receiver's accuracy and ability to maintain a position fix with a partial view of the sky. Note the 10-foot accuracy in the above screenshots. In my location in northern Arizona, more GLONASS satellites are usable than Galileo satellites, but you'll need to experiment under your own conditions.

When I started using the Garmin Oregon 600, I noticed that the battery life was much less than the Garmin GPSMap 62s. I attributed that to the touchscreen or the GLONASS receiver, which the Oregon 600 has but the 62s does not. I just received the new GPSMap 64s, which is the 62s updated to include GLONASS, and that gave me the chance to test the two under similar conditions. Much to my surprise, I found the battery life of the Oregon 600 to be about the same as the 64s, both with GLONASS enabled and disabled.

The GPSMAP 64 series is a much-anticipated update of the 62 series to include reception of the Russian GLONASS satellites. As already proven by the Garmin Oregon 600 series of touch screen trail GPS units, adding GLONASS to the US GPS satellites slightly increases the accuracy and significantly increases the reliability of the navigation fix. With more satellites to use, the Oregon 600 maintains its satellite lock under partially obscured skies, such as in canyons and heavy forest cover. Having more satellites available also makes it less likely that the accuracy of the fix will suffer from poor satellite geometry, which can happen if all the usable satellites are in a line.

Much-anticipated? Well, not all of us like touch screens for field use. Although the Oregon 600 series is vastly improved over its predecessor 400 and 500- series, I still prefer buttons while wearing gloves and in cold weather.

All of the 64-series units support additional Garmin maps, as well as custom maps. The base 64 model comes with a basemap, and 250,000 preloaded geocaches from geocaching.com. The 64s adds an electronic compass and altimeter, and the 64st adds TOPO U.S. 100K maps.

I recommend the 64s, since there are plenty of free, high-quality maps available from gpsfiledepot.com as well as other sources.

Garmin 010-01199-00 GPSMAP 64 Worldwide with High-Sensitivity GPS and GLONASS Receiver

A Workable Touchscreen Trail GPS!

While touch screens work well on street GPS receivers, I've always preferred trail receivers with buttons. I've found touch screen trail GPS units to be unresponsive, hard to see in bright sun, and completely unusable with gloves. Marking my current position as a waypoint, which I'm constantly doing as I map trails, is a pain on older touchscreens. In the past I haven't been a believer in touchscreen trail GPS receivers. The new Garmin Oregon 600 is making a dent in that belief.

All three eTrex models are waterproof and feature paperless geocaching. Both have basemaps- the eTrex 20 and 30 adds color screens, a micro-SD card slot, and the ability to add maps, including custom maps. The eTrex 30 further adds a three-axis compass and a barometric altimeter.