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graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 9:55 am
by TerraMer
I'm doing the AAWT this summer and, just to fill in spare time, I'm drawing a profile but have forgotten what is the best interval and would appreciate your advice.

Considering it's length and not wishing to use wads of paper, yes, drawing it with paper and pencil, would a good interval be 1km across to 100m up allowing 1cm for each? I was taught this in high school but haven't used it for years and, alas, like learning a language while on holidays and never using it again, it is lost.

I enjoy doing these things old school. Feels better than asking a little machine to do all the thinking or using someone else's profiles from their track notes. (I refuse to conform with technology :mrgreen: )

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 11:48 am
by bernieq
IMO, a profile (with added information) is a very useful adjunct to map/compass/gps. I generate one for each significant walk I do.

Your suggested V:H ratio is 1:10 and a scale of 1:100,000 (ie map to real). If you are just drawing one profile, the ratio and scale don’t matter – only when comparing one profile with another does the ratio needs to be the same. Hence, all my profiles use the same ratio (which happens to be about 1:4.5)

However, with your scale of 1:100,000 (1cm map = 1km real) for the whole 665km AAWT, you’ll need 6.65m of paper !

Section 04 profile.JPG
Profile - AAWT from Mt Hotham to Omeo Hwy
The above profile has a V:H ratio of 1:4.5 and a scale of 1:8,200

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 11:55 am
by GPSGuided
Impressive graphs. Question. How did you generate that in such smoothness and detail? Altitude reading every 500 paces?

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 12:16 pm
by bernieq
GPSGuided wrote:How did you generate that in such smoothness and detail?
Hmm, it does take a bit of work.

1. Use a mapping program (Oziexplorer, Basecamp etc) to draw a track and save it as a gpx.
2. Upload the gpx to GPSVisualiser and add altitude data.
3. Reload it to the mapping program and display profile.
4. Do a screen capture and paste into a graphics program (eg Paint) – add text (waypoints, features, etc.)

The above profile is out of OziExplorer.
Here's a link to another profile (out of Basecamp) - http://www.tramper.co.nz/?8716

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 12:28 pm
by GPSGuided
Thanks Bernieq. So it was a CAG (Computer Assisted Graph). I originally thought it was done manually, per TerraMer's intention. If any one can get to that kind of detail manually, I'll throw my Garmin out the window. ;)

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 1:15 pm
by TerraMer
Incredible work bernieq :) Thanks
Numbers fail me, could never understand scales. I'll try your scale.
It will certainly make the ascents look dramatic! ;)

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 3:05 pm
by icefest
If you are planning on taking paper maps (and I suggest you do) have you considered drawing the height profile on the back of each map?
When I do longer trips I usually write trip notes on the back of the relevant map, that way do you not need to carry Chapaman's trip notes.
It's also fun to preplan the trip and you'll be able to (if you want) compare current satellite imagery with the planned trip to make any changes.
You can dump the used maps in you old food caches and have the location of on the map too. Don't forget GPS waypoints.

If you can get a hold of the map before lamination you'll even be able to use pencil and not be worried about water damage.
Take a small permanent marker, together with metho you then have an emergency (mostly) waterproof notepad.

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 3:19 pm
by GPSGuided
icefest wrote:If you are planning on taking paper maps (and I suggest you do) have you considered drawing the height profile on the back of each map?

The back of the current edition Topo from LPI is an equally sized satellite image. No room to write.

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 8:18 pm
by madmacca
The profile's in Chapman's AAWT guidebook are 2 km to 1 cm horizontally, and 400 m to 1 cm vertically.

If you could get in 4 4 x 25 cm strips on an A4 landscape page, you could fit the entire AAWT on 2 double sided A4 pieces of paper. This would give you 1600 m vertical variation per strip, which should be fine, although you would need to alter the start and end scale to cope with the low points of Thompson River and the Mita Mita, and also the peaks of the Main Range.

1 cm to 1 km would take 4 double sided A4 pages.

Re: graphing altitude profile intervals?

PostPosted: Tue 17 Sep, 2013 9:35 pm
by icefest
GPSGuided wrote:
icefest wrote:If you are planning on taking paper maps (and I suggest you do) have you considered drawing the height profile on the back of each map?

The back of the current edition Topo from LPI is an equally sized satellite image. No room to write.

Sounds like you guys are way ahead of Vicmaps.

Re: graphing altitude profile intervals?

PostPosted: Wed 18 Sep, 2013 9:14 am
by TerraMer
Icefest, thanks, I will do that on the Vic maps. Makes good sense. All the rest I have done or plan to do :D
I'm a paper map and compass walker but probably waste far too much time on google Earth zooming in and out along the track and side tracks, checking out some amazing photos. Some of them are truly incredible photos :mrgreen:
I tend not to read other people's track notes, not very generous of me considering I write blogs nobody reads :| After over 20 years on the Great Alps walk (AAWT) I haven't fully read any published track notes, only skimmed through them, but I get engrossed in logs in the huts and Timbertops' boxes. I wrote track notes on the back of an early set of maps and years later, reading them, I was embarrassed by my ignorance and even more embarrassed that I had lent them out to other walkers :oops:

Cheers
:)

Re: graphing altitude profile intervals?

PostPosted: Wed 18 Sep, 2013 9:19 am
by TerraMer
Thanks, that sounds workable. I'll give it a go. Cheers :)

madmacca wrote:The profile's in Chapman's AAWT guidebook are 2 km to 1 cm horizontally, and 400 m to 1 cm vertically.

If you could get in 4 4 x 25 cm strips on an A4 landscape page, you could fit the entire AAWT on 2 double sided A4 pieces of paper. This would give you 1600 m vertical variation per strip, which should be fine, although you would need to alter the start and end scale to cope with the low points of Thompson River and the Mita Mita, and also the peaks of the Main Range.

1 cm to 1 km would take 4 double sided A4 pages.

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 9:07 am
by frenchy_84
I know you said that you wanted to do it by hand ratehr than use a computer but if your wondering about scale it might help to quickly create one in excel first to work out what HZ/V scale works best. Also most people already know this but ive just discovered how easy it is to create a vertical profile in Google earth, simply create a path than right click on it for vertical profile, it also allows you to move the curser along the profile which will move an arrow on the ground. No GPS data necessary.

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 11:15 am
by bernieq
frenchy_84 wrote:ive just discovered how easy it is to create a vertical profile in Google earth, simply create a path than right click on it for vertical profile
GE is OK as far as it goes but a major limitation (IMO) is that the scale and ratio are not easily controlled/set.

As a one-off profile, that may be acceptable. However, if you want to be able to compare (particularly gradient) from one track to another, you need to have the same ratio (and the same scale is advantageous) across the various profiles.

(note : ratio is V:H (ratio of vertical to horizontal measurement on paper). scale is the ratio of horizontal distance on paper to actual)

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 11:46 am
by frenchy_84
bernieq wrote:(note : ratio is V:H (ratio of vertical to horizontal measurement on paper). scale is the ratio of horizontal distance on paper to actual)


The slope of a line is specified as a ratio. The scale of a profile plan can be specified with both a horizontal and vertical scale.

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 1:13 pm
by bernieq
The reason for the note, Frenchy, was because I’d used these terms in my previous post and wanted to ensure (as far as possible) that the meaning was understood.


Ratio is a general (mathematical) term (ie fraction, percentage etc). I was defining how I was using ratio, in this circumstance.

Scale is a ratio relating (usually) measurement on a map/plan/elevation to measurement ‘on the ground’. Again, I was defining how I was using it in this circumstance.

For this discussion, there are 4 measurements : vertical and horizontal on the profile and on the ground (Vp Vg Hp Hg).

I’ve chosen to relate these measurements by the ratio Vp : Hp and the scale Hp : Hg – other combinations would also be sensible (eg as you suggest Hp : Hg and Vp : Vg)

frenchy_84 wrote:The slope of a line is specified as a ratio
The slope or gradient of a line can be specified as a ratio (V:H) but can also be specified in degrees (or even radians). My point was that to be able to look at profiles and get a sense of the steepness of slopes, you need to have the same ratio (as defined in this context) across the profiles.

The two profiles below are of the same track – but at different ratios. The one on the right looks a lot more manageable !
scales.JPG
scales.JPG (18.87 KiB) Viewed 18777 times

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 3:25 pm
by Scottyk
frenchy_84 wrote:
bernieq wrote:(note : ratio is V:H (ratio of vertical to horizontal measurement on paper). scale is the ratio of horizontal distance on paper to actual)


The slope of a line is specified as a ratio. The scale of a profile plan can be specified with both a horizontal and vertical scale.


Bernie is spot on, no need for correction

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 3:29 pm
by frenchy_84
..

Re: graphing altitude profile intervals?

PostPosted: Mon 07 Oct, 2013 5:17 pm
by TerraMer
Great answers for those who can use computers. Too much maths and techie stuff for me. My question was too big for my inability to understand technology.
I did end up drawing the AAWT profile with paper and pencil and it took 6 sheets of double side A4 2 tier. It was a great way to procrastinate.

Re: graphing altitude profile intervals?

PostPosted: Thu 28 Jan, 2016 4:33 pm
by StephenG
bernieq wrote:IMO, a profile (with added information) is a very useful adjunct to map/compass/gps. I generate one for each significant walk I do.

Section 04 profile.JPG
The above profile has a V:H ratio of 1:4.5 and a scale of 1:8,200


Hi bernieq
I recently walked half of the AAWT in several sections with a friend who was completing it all. I am now compiling a photo album for him and would like to include vertical profiles of the track. Do you have profiles of the type you attached to this post for the whole track that you would be willing to share?

Re: graphing altitude profile intervals?

PostPosted: Sun 31 Jan, 2016 3:39 pm
by bernieq
Hi StephenG,

I'm not sure what I have would be of much use. I have 3 sections : Rawson to Mt St Bernard, Mt Loch carpark to Omeo Hwy and Omeo Hwy to Vic border.

Although the V:H ratio is the same in each, the layout is different (ie not a lot of consistency). As well, it's what we walked and not the official AAWT (although most of it is, obviously). They are in pdf format so you'd need an editor to modify them.

If you still want them, PM me with your email address and I'll send them - all of my stuff is Creative Commons Attribution-Non-Commercial-Share Alike : http://creativecommons.org/licenses/by-nc-sa/4.0/

Re: graphing altitude profile intervals?

PostPosted: Tue 02 Feb, 2016 10:33 am
by GBW
Had a little play around with this concept yesterday...managed to create a profile from a GPX file containing tracks and waypoints then with some simple trig plot the waypoints along the line. Needs some work but it's a start.

Profiles AAWT_1.jpg
AAWT Profiles 1

Re: graphing altitude profile intervals?

PostPosted: Wed 03 Feb, 2016 12:40 pm
by GBW
A few minor adjustments and it works well. The biggest problem was preventing overlapping text...

AAWT_Profiles_05.JPG