Delorme Support Websites Pulled by Garmin??

[adamschneider]

Okay, yesterday we did a couple loops around Silver Falls... My (barometric-damped) Garmin reported 1700' EG.

I bet a barometer would have a hard time at Silver Falls: lots of air moving around, weird enclosed spaces, etc. And of course there are times when your GPS (or phone) will COMPLETELY lose a signal because you're under a canopy of rock.

(In the end, the best way to calculate EG is still a good topo map and a lot of free time.)

[kepPNW]

Okay, yesterday we did a couple loops around Silver Falls... My (barometric-damped) Garmin reported 1700' EG.

I bet a barometer would have a hard time at Silver Falls: lots of air moving around, weird enclosed spaces, etc. And of course there are times when your GPS (or phone) will COMPLETELY lose a signal because you're under a canopy of rock.

That's what's nice about not using a barometer, per se, for EG, I suppose. It's just used to modulate the wild swings present in GPS data from point to point, and for that it can (with a good algorithm) do pretty well.

[Koda]

Okay, yesterday we did a couple loops around Silver Falls... My (barometric-damped) Garmin reported 1700' EG. My phone exported a track that had recorded 7000' EG!!! But the phone app also reported, after running the dampening algorithm that it thought we had 1300' EG. (I think that last number, far from super-precise, might nonetheless be closest to reality.) Oh, and the X/Y was much better from the phone, too, since it's 5 years newer than the (pre-GLONASS) Garmin.

Interesting, I don't keep track of EG but I don't recall ever noticing any of my phones GPS track elevation gain being radically far off like that.

If anyone is bored and wants to check actual vs reported attached is one of my recent tracks from my phone. I believe its only about 200ft off the actual EG of Kings ?

kings mountain 201606190620.gpx

(56.04 KiB) Downloaded 212 times

Reference: http://www.oregonhikers.org/field_guide ... ntain_Hike

[kepPNW]

Interesting, I don't keep track of EG but I don't recall ever noticing any of my phones GPS track elevation gain being radically far off like that.

Probably all those canyons and overhangs that wreaked total havoc yesterday... Impressive how the barometric damping smoothed it all out, though!

[RobFromRedland]

Interesting, I don't keep track of EG but I don't recall ever noticing any of my phones GPS track elevation gain being radically far off like that.

Probably all those canyons and overhangs that wreaked total havoc yesterday... Impressive how the barometric damping smoothed it all out, though!

Just curious what phone you are using and what app did the "damping"??? I currently have a Galaxy S6 and am in the market for a new phone. I'm considering an S7 or possibly the S8 (they are officially announcing it tomorrow). I use the Backcountry Navigator app and really like it for the maps and aerial images you can store offline. I've found my phone to be very comparable to my 60csx, although I'm not sure I ever compared elevation profiles too much, just the tracks themselves.

[Koda]

Okay, yesterday we did a couple loops around Silver Falls... My (barometric-damped) Garmin reported 1700' EG. My phone exported a track that had recorded 7000' EG!!! But the phone app also reported, after running the dampening algorithm that it thought we had 1300' EG. (I think that last number, far from super-precise, might nonetheless be closest to reality.) Oh, and the X/Y was much better from the phone, too, since it's 5 years newer than the (pre-GLONASS) Garmin.

ok I found a very old track of mine from 2013 of Silver Falls loop hike and the EG showing there is 2839. So not as bad as 7000' but still very off. This was if I recall my old LG G2 phone.
http://www.gpsies.com/map.do?fileId=bmejadozxytfciny

for reference the Oregon Hikers field guide says the hike is only 640' EG... is that right? http://www.oregonhikers.org/field_guide ... _Loop_Hike

This still doesn't change my opinion on using a phone for gps but its good to know how far off it can be. I will have to see what my current phone is measuring next time I head out...

[adamschneider]

If anyone is bored and wants to check actual vs reported attached is one of my recent tracks from my phone. I believe its only about 200ft off the actual EG of Kings ?

kings mountain 201606190620.gpx

Reference: http://www.oregonhikers.org/field_guide ... ntain_Hike

What was the "reported" EG? Adding up all of the elevation differences in that file yields 3579' of gain, which is off by more than 1000'.

(Running it through GPS Visualizer with DEM elevation data replacing the GPS elevation numbers yields 2662', which is MUCH closer to reality and proves that GPS devices just generally suck for measuring altitude.)

[Koda]

What was the "reported" EG? Adding up all of the elevation differences in that file yields 3579' of gain, which is off by more than 1000'.

that file was transferred over to my PC and no longer in my phone (I switched phones since then) so I don't have a way to check what Backcountry Navigator (BCN) reports its EG anymore. Unfortunately I don't have any new 'on trail' tracks to measure against know EG's.

Attached is a gps track that's still in my phone but all off trail. BCN says its "altitude gain" (EG) is 1548'. Id be interested to see if BCN is using an alithogram to smooth out the EG reading from the actual?

yurt 201703030328.gpx

(102.49 KiB) Downloaded 215 times

[kepPNW]

Just curious what phone you are using and what app did the "damping"??? I currently have a Galaxy S6 and am in the market for a new phone. I'm considering an S7 or possibly the S8 (they are officially announcing it tomorrow).

I have the GS7, and am still wrestling with AlpineQuest as the GPS app. It was this feature, specifically, that I was after. I'd written to BCN, to ask them if they supported the phone's barometer, and they said no. Here's the display of stats it offers for any track.[/quote]

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[RobFromRedland]

I have the GS7, and am still wrestling with AlpineQuest as the GPS app. It was this feature, specifically, that I was after. I'd written to BCN, to ask them if they supported the phone's barometer, and they said no. Here's the display of stats it offers for any track.

Thank you. Good to know. I like what I'm hearing (rumors) on the S8, but it may be rather expensive. Depending on what they actually release, I think I will either end up with an S7 or an S8. Battery life will be a factor too. I'm not crazy about the battery life on my S6, but I get around it by having a 10,000 mah external battery. The really cool thing is that I will have a microSD slot!

I like my phone way better than my 60csx - mostly due to a better/larger screen, more features and the ability to load useful maps to it. The maps on the 60csx were terrible, and I never wanted to shell out for the expensive 100k or 24k maps for it.

Thanks again!