Thursday, June 25, 2015

Explorer Test Part II

Today I did two loops of the 4.35 mile trail that included the Guadalupe River State Park trails: Painted Bunting, Live Oak, and River Overlook.  So by the state park map, I did 8.7 miles in roughly 3 hours 10 minutes by my watch.  I did the first loop in 1 hr 30 minutes +/- 1 minute, but forgot to check my watch immediately when I finished the second loop.  The temperature rose from 75 when I arrived to about 88 when I departed.  The heat really slowed me down the last half of that second loop.

So by my calculation I did 2.9 mph the first loop, and 2.6 mph the second loop.

I had two devices tracking my progress.  First, I left my iPhone 5S on (cellular, no WiFi or bluetooth) and tracked my progress via Gaia.  The phone is down to 9% 4 hours after finishing the hike.  The battery drain was probably from both the GPS and Gaia keeping the screen on; i.e., when I pulled it out of my pocket after the hike, the screen was dimmed but still active.

I thought I had completely turned the phone off before leaving the trail head, but I only shutdown the GPS and Gaia and turned off the screen.  Gaia shows that I went 8.43 miles over 3 hrs 17 minutes.  But I unloaded the pack and changed shoes then stopped Gaia and the Explorer, so there are a few minutes included in each device's track after I stopped hiking.  Here's my track from Gaia:
I also had the DeLorme inReach Explorer sending my location to MapShare every 10 minutes and logging my location every 10 seconds on the device.  Here's the MapShare map showing the 10 minute sends for the two loops, overlaid with yesterday's relatively high resolution, single loop log from the device.
Please remember I have not yet synched the Explorer to upload the 10 second log track from today.  You'll notice in the stats on the left that the Explorer thinks I traveled only 5.83 miles.  It doesn't know anything about the trail path during those 10 minute intervals.  The trail is very winding.  Hence, it thinks I went very slowly at only 2.25 mph (compared to your speeds, I might be slow at 2.7 mph too).

The conclusion here is that 10 minute tracking on MapShare just isn't an accurate representation of the length of the trail or your speed.  Unless you get the very expensive, top-level plan, you cannot send your location more frequently than 10 minutes.  The highest end plan only allows sending every two minutes.  Still, the Explorer does a good job of reporting your instantaneous location.  All of the locations are right on the detailed track from yesterday.  You cannot tell from the 2-D map, but if you click on a location, it also shows your speed, which seemed pretty realistic.

I did fully turn off the Explorer before leaving the trail head, so the power usage ought to be good.  It went from 98% down to 92% or 6% battery usage over 3 hours at the highest logging/sending rates.  That suggests the Explorer could be good for 50 straight hours at that rate.  Very promising for longer backpacking trips with minimal location sends and track logging.

Next, I synched the Explorer to the DeLorme site, and obtained today's updated track and stats.  This uses the every-10 second-logging function.
Note that today's track is still overlaid on yesterday's every-1 minute-logged track, explaining the couple of sections where the tracks diverge.

But the stats are still not very good.  It shows only 8.29 miles and an average speed of 2.56 mph.  If you are interested, here's a *.gpx file of the track created by the DeLorme export function:

download track for Guadalupe River State Park hike

My conclusion is that the Explorer will do a good job of sending an accurate location.  But don't trust stats on distance or speed.  I won't say the stats are wrong, as I only have one other unvalidated source.  But the Texas state parks map shows the trail mileage down to hundredths of a mile.  That doesn't mean they are actually that accurate, but I have two sets of stats with significant differences.  My conclusion; don't trust either!

Figured I might as well add a photo from the hike today.  This is part of the area where they did a controlled burn back in February 2015.  Have a good day.

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