proposal: GPS try-it-out (Middlesex Fells?)

[arghman]

OK. I've been meaning to do this, and have a reason now that I'm on the lookout for yet another GPS.

I propose a "GPS try-it-out" session somewhere in the MA / Southern NH area, on a weekend in January. Middlesex Fells seems to come to mind as a convenient place, although I haven't been there enough to suggest some good trails that have a mix of tree cover / etc. (Bear Brook SP in Allenstown NH would be closer to me...)

Does anyone want to suggest a date/time (9am?)/place?
If you have one, bring your GPS receiver and some spare batteries. It would be great to find someone in the area w/ a computer to try uploading/downloading waypoints also.

I will bring my Garmin eTrex Legend and Lowrance iFinder PhD, and can show what I like & don't like about either.

I'll offer a prize, too: whoever lets me try a GPS that meets my needs & that I like the most (I've got my eye on the Magellan eXplorist series), I'll buy you a beer afterwards.

 

[DougPaul]

I presume you have seen our recent GPS bakeoff threads: http://www.vftt.org/forums/showthread.php?t=14406 and http://www.vftt.org/forums/showthread.php?t=15025.

These tests included the basic (yellow) eTrex and the eTrex Vista, the 60CS and the 60CSx (all Garmin). We tried to include a Magellan unit, but it failed part way through and had to be dropped from the test. (Reason unknown, so this should not be considered evidence against it.) Of those tested, one can conclude that the 60CSx (and the 76CSx--same electronics in a different package) gave the best satellite tracking and position repeatability in reasonably difficult hiking conditions.

I assume that you are interested in performance under difficult conditions typical of those that might be found while hiking. (Essentially all GPSes will work well in good signal conditions.) Thus, I suggest that this might not be the best time of year to test GPSes. If you wait for the trees to be in full leaf and the sap flowing, there will be more more signal degradation to deal with. Similarly, the Middlesex Fells Reservation is too flat for a difficult test. A narrow valley will block out part of the sky and make the GPS's job more difficult.

The above were some of the reasons that we chose Greely Ponds Tr (a narrow valley) while the trees were still in leaf for the first bakeoff. Difficult, but not impossible (ie a deep slot canyon). The second was performed on treed routes near my home for convienence--I made 24 separate tests...

Unfortunately, we were not able to include other brands in our bakeoff tests. Of those tested, the 60CSx appeared to be the best under realistic hiking conditions. If you run some tests, I suggest that you include this unit--it may allow you to tie your results into ours.

The 60CSx uses the SIRF Star III GPS chipset. One could reasonably expect other hiking GPSes using the same chipset to have similar tracking performance. (The basic chipset outputs time, 3D position, and 3D velocity.) The rest is user interface and presentation--you should be able to form your own preferences on this part.

Doug

 

[arghman]

I assume that you are interested in performance under difficult conditions typical of those that might be found while hiking. (Essentially all GPSes will work well in good signal conditions.)

Actually, the user interface is the big issue for me, along with issues related to data storage. There are a number of qualities about GPS receivers that are nearly impossible to determine even from user manuals.

My Lowrance, for instance, has a "limit" of 1000 waypoints that is not derived from the number of waypoints but rather from an autosequence counter that stops at 1000. I think I have a workaround but it's a very inconvenient thing. My GPS is used almost exclusively as a waypoint acquisition tool. Between April and November of this past year, I acquired over 850 waypoints, with 20% of these taken on two days alone (87 wpts on May 6, 89 wpts on August 26) -- on days like these I am doing a mad dash trying to write down data and take pictures and I just don't have time to play games trying to enter my own unique waypoint names, I need the GPS to do it for me, quickly.

I did see the bakeoff threads and they were very helpful. Also your comments about places / times to test signal quality are helpful. If I can get a workaround for my problem with the Lowrance, I may wait before buying until there are more units using the Sirf III.

Thus, I suggest that this might not be the best time of year to test GPSes. If you wait for the trees to be in full leaf and the sap flowing, there will be more more signal degradation to deal with.

unfortunately I am very busy during the botanical field season.