Another Back to Back TR

[Zé]

http://socalhikes.com/2009/11/double-the-trouble-skyline-back-to-back/

this was a painful one. great job by Steve as we pushed really hard the 2nd time. like really hard.

[Hikin_Jim]

Dude, nice job. You're moving mighty fast when you wait for Steve so you can go slower.

[tinaballina]

Nice work Joe, nice work.

[Zé]

Dude, nice job. You're moving mighty fast when you wait for Steve so you can go slower.

slower for Steve? nah. I just got a 5 min head start on him. steve was blazing!

[Rick Kent]

Hey Joe, what did you say the total elevation gain from the museum to the tram is? Sounded like you had examined your GPS data to arrive at a fairly accurate number.

[Zé]

yeah I collect data with a 1 sec sampling. then I 'smooth' with various filtering settings, and I plot the raw and the smooth curves of the elevation.

I can get a good look of what is 'real' and 'fake' elevation gain (due to inherent error in measurement). I can assess which smoothing has the best estimate. plus I look at the total gain calculation for the others too.

for this one, I'm pretty sure its right around 8400 ft gain.

that's 25,200 ft gain for 3 !!!!

[lee]

Hi Joe, FWIW: My data from the 2 Garmin toys I brought with me on the hike which I kept on the top compartment of my daypack. This compartment was at just below my shoulders and faced the sky the entire hike. I turned them on 15 minutes before the hike, reset the elevation number of both using GPS elevation with +/- 15 ft accuracy. I recall the barometric pressure elevation was about 30 ft higher. I started the recording from the street/Museum Dr just outside the museum parking lot before the trail head. I ended the recording at the benches at the top of the cement walkway outside the lower lever of the tram building.

* GPSmap 60CSx (data has no interuption)
22691 points of 2-second data; 12.07 miles; elapsed time: 12.36:29
1 11/7/2009 6:07:34 AM 528 ft N33 49.518 W116 32.945
...
22691 11/7/2009 6:44:03 PM 8505 ft N33 48.781 W116 38.315
---> 8505 ft - 529 ft = 7976 ft


*Vista CX (data has 1 interuption at 7:55:07 AM 1752 ft N33 49.414 W116 33.752)
15104 points of 3-second data; 11.77 miles; elapsed time: 12.35:47
1 11/7/2009 6:09:38 AM 519 ft N33 49.515 W116 32.942
...
15104 11/7/2009 6:45:25 PM 8490 ft N33 48.783 W116 38.320
---> 8490 ft - 519 ft = 7971 ft

(My Vista CX is the old/discontinued unit not the new Vista HCX with the hi-sensitivity antennae)

[lee]

Another thing, do you know of an application that would get me the cumulative elevation from these GPS data?

[Zé]

yes your absolute elevations look correct. the cumulative gain will be a bit more due to some portions then went downhill then back uphill.

i have a 60CSx and it gives me its estimate for cumulative gain (which is pretty good) on the display. I process my data in Matlab. I'm sure there are programs you could use (upload to everytrail.com for instance) but I don't know their algorithms for filtering. I know they aren't accurate.