Although I’ve never completely understood the benefit of using WAAS in an outdoor handheld GPS there has been quite a bit of stir on the Oregon wiki about poor WAAS/EGNOS performance.  We posted about the problems with WAAS when we first tested the Oregon 400 almost two years ago and reiterated the same concern on the 550 last summer.  The Oregon’s smaller sibling, the Dakota, also suffers from the same issues which are:

  • long WAAS acquisitions times (> 5 minutes) even with direct view to an optimal WAAS/EGNOS satellite
  • inability to hold WAAS signal under any type of canopy
  • in the event of signal loss the unit makes lengthy hunts through a sequence of WAAS/EGNOS satellites which aren’t optimal at the user’s location

Late last week Garmin announced a beta which included new GPS firmware for the Oregon x50, Oregon x00 and Dakota.   All three drops included an “Improved WAAS performance” release note, so we spent some time over the long weekend to test WAAS on an Oregon 550 and Dakota 20.  Here’s what we observed:

  • Acquisition time with a clear view of the most optimal (ie. highest elevation) WAAS satellite is faster.  After the initial lock which still took 5-7 minutes both the Dakota and Oregon acquired WAAS within 30-60 seconds after power on.  The Dakota takes about 5-15 seconds longer than the Oregon in most tests.
  • Under tree cover the performance is marginally better but not enough that I could observe any improvement in my location accuracy.
  • The most frustrating thing is when WAAS signal to the most optimal satellite is lost the GPS proceeds to hunt through a long list of satellites which are at very low elevation (2-15 degrees).   The unit spends about one minute waiting to lock on each of these satellites (and never does) which means that it takes about 8-10 minutes to cycle back to the most optimal satellite effectively rendering WAAS/EGNOS useless for that 10 minute period of time unless you are willing to power cycle the unit.

In short, there are improvements in WAAS/EGNOS but practically speaking I don’t see that the improvements add any value unless you are operating in an environment without tree cover such as desert or alpine hiking, on the water or in the air.  I was not able to get WAAS long enough on my test track to see if the accuracy of the unit improves with WAAS, although I did notice my EPE drop to 9 feet and based on BirdsEye maps my position looked about the same as it did without WAAS (both were good).

The complete set of release notes for this beta software reveals some other significant bug fixes and improvements:

  • Added brightness adjustments for BirdsEye imagery.
  • Improved WAAS performance.
  • Improved speed, trip odometer, and stopped/moving time data fields while in low velocity.
  • Fixed issue with map POI’s showing twice for a single point.
  • Fixed elevation profiles to always use the most detailed DEM data loaded.
  • Fixed future plot with tracks that have no elevations in them.
  • Fixed issue with calculator % function.

If you are looking for the BirdEye brightness adjustments you’ll find them under Setup>Map>Map Information Select Map>BirdsEye Satellite Imagery.  Previously you would see just “Enable” and “Disable”, whereas with this new release you will find, “Enable – Brighter”, “Enable – Bright”, “Enable – Normal” and “Disable”.    I’ve provided some screenshots to illustrate the differences.  My preference is for the “normal” mode but it might be worth setting this parameter to “brighter” in a “high visibility” profile if you are using the unit under bright overcast skies and are having problems seeing BirdsEye maps.

Brightness control

Brighter

Bright

Normal

We were also curious about the low speed data field improvements because I’ve found speed, stopped time and trip odometer to be unreliable since day one.  Based on my tests Garmin has made some improvements, especially with “stopped time”.  Previously I would see much more stopped time recorded by both the Dakota and Oregon – during my test loops over the weekend I only observed a few 10′s of seconds of stopped time as compared to several minutes in past tests.  Speeds reported below 3mph also appear more stable.  The trip odometer is a little better, particularly on the Oregon, measuring closer to the tracklog but still underestimating the distance of my track by ~2-4%.  The Dakota error was higher, on some tests it was closer to 10% underestimation.  I’ll attribute this to the Dakota’s somewhat inferior antenna design, I’ve always seen poorer sensitivity on the Dakota as compared to either of my Oregon’s and I’m guessing that that this leads to more variation in the speed and trip odometer data.

At least one user has reported a problem upgrading an Oregon x00 to this release which resulted in a bricked unit (System Software Missing) so please consider this before upgrading. I have not experienced any problems upgrading my three units, but there is always a risk associated with beta upgrades.  There is one new bug introduced which causes a hang when you attempt to navigate to all POIs (WhereTo?>All POIs).  You’ll need to pull the batteries to recover if you encounter this.   I’ve also experienced one shutoff on my Oregon 550t while editing a waypoint but it is not reproducible.

These beta releases can be downloaded here:

Oregon x50 (3.51/4.46)

Oregon x00 (3.81/4.46)

Dakota (3.11/4.46)

Join us on the wiki discussion threads (Oregon x00, Oregon x50, Dakota) to let us know your experiences if you decide to take the beta upgrade plunge!

Related posts:

  1. Garmin Oregon/Dakota Beta Adds Geocache Filtering
  2. WAAS problems on Oregon and Colorado
  3. Garmin Oregon 450/550 and Dakota Beta Fixes Bugs
  4. Garmin Releases “Do-Over” for Oregon and Dakota
  5. Oregon Firmware 2.70/2.58 Available — Improved WAAS, Marine