Full Elevation Profile for the AT

[refreeman]

Mr. Parkay, beautiful work. Your Full Elevation Profile for the AT fills a gap in my AT data.

[BigCat]

Neat project, Mr. Parkay! I do have one question for you though: What is the vertical exaggeration ratio?

[Mr. Parkay]

Neat project, Mr. Parkay! I do have one question for you though: What is the vertical exaggeration ratio?

Hello, the vertical exaggeration is different on the Big AT Profile.. as compared to the printable profiles:

Big AT Profile: VE = 6.06
Printable Profiles: VE = 7.63

I only have one of the ATC map/profiles... which has a VE of 5.8.

I'll include this with the profiles next time I update them

[BigCat]

Big AT Profile: VE = 6.06
Printable Profiles: VE = 7.63

Cool. Just as some friendly input, I've had several people with extensive work creating topographical maps tell me that a VE of 5.00 is optimal for simulating a walker's experience with elevation changes.

[Mr. Parkay]

Cool thanks for the info.

[Frosty]

Cool. Just as some friendly input, I've had several people with extensive work creating topographical maps tell me that a VE of 5.00 is optimal for simulating a walker's experience with elevation changes.

I'd rather have more exaggeration to better see the how it changes.

[Frosty]

Just looked over the AT profiles. Totally awesome, Mr. Parkay. Thanks for doing this. It must take a lot of time and we are fully appreciative.

It's fun looking at them and remembering, "Oof, I remember that section!"

[Tom Murphy]

Great job.

Can you publish the dataset [miles vs elevation]?

I would like to see the y-axis [elevation] be a consistent scale for all the graphs; say 7000. feet.

I think you tweaked those scales in order to add the labeling in.

Great Job !

[BigCat]

I'd rather have more exaggeration to better see the how it changes.

Absolutely, but a lot of that has to do with the number of contour points. I'd say with this amount of data anything between 5 and 7 would be good. Once you get much higher than that the slopes become steeper than what a hiker actually experiences.

Can you publish the dataset [miles vs elevation]?
I would like to see the y-axis [elevation] be a consistent scale for all the graphs; say 7000. feet.

I'd be curious to see the raw data as well, did you pull it from the Companion charts?

[Mr. Parkay]

Hey Guys,

I've made some adjustments to the Big AT profile... so here's the new Link:

Big AT Profile New Link

unfortunately the old link died when I updated the file.... so I'm sorry for any confusion. Eventually I'll create a web site for all of these map creations which I suppose will make the problem obsolete.

The changes are relatively small... I just added some more placemarks and corrected some mistakes. For example, Dragons Tooth and Mt. Lincoln were incorrectly labeled in the original version.

[10-K]

I'd rather have more exaggeration to better see the how it changes.

Help me out here... Exactly what is a layman's definition of "vertical exaggeration"?

[Mr. Parkay]

Absolutely, but a lot of that has to do with the number of contour points. I'd say with this amount of data anything between 5 and 7 would be good. Once you get much higher than that the slopes become steeper than what a hiker actually experiences.

I'd be curious to see the raw data as well, did you pull it from the Companion charts?

I'd be happy to post the "raw data" used to create the profiles. Although I'll need to explain some things first... since there are different levels of raw data depending on how much processing it has gone through. Here's an explanation about some of the data processing used:


1. The GPS track that I use is a modified version of the ATC's AT shape file .. which I have altered and processed in a whole bunch of ways to make the data more useful for my purposes. (I need to put a note about this on the profiles)

2. After modifying the GPS track I ended up with 104329 lat/lon points.

3. I used "Wissenbach Map" to add elevation to all 104329 data points.

4. Next I had to calculate the distance between each of the lat/lon points. For this I borrowed some python code, which uses Vincenty's formulae to calculate the "flat land" distance between points... This worked out to about 2017 miles.

5. I wasn't satisfied with the "flat land" distance, so I wrote some code which takes into account the "3d distance" added by mountains & such. It ended up adding about 15 miles, but I'm not a mathamatician, so my calculation could be off. This gives a total distance of 2032.7 miles, which is a lot different than the accepted 2174 miles that most of the guide books use. I'm not sure why the difference is so large, but I'm assuming that the 2174 number is a lot more accurate since it was probably calculated with a measuring wheel.

6. When I was creating the profiles I wanted the miles on the x-axis to match up with the distances that guide books use... since it would be confusing otherwise. To achieve this I wrote some python code which essentially warps the data points around "control points" that I have placed throughout the profile. I have about 100 control points, which seem to do a good job at altering the profile.

7. Then I use matplotlib to plot the data and create the nice looking pdf files.

The data in steps 4, 5 and 6 would all create slightly different profiles if they were plotted... although I prefer #6. Anyow, I'll generate some text files with this data and post it pretty soon. Perhaps it will be usefule if someone else wants to make some cool profiles!

[Mr. Parkay]

Here's a link to a zip file containing the x/y coordinates used to create the profiles. The zip contains 3 text files, which correspond to the 3 levels of processing described above. So one file has "2d" data points, which gives a length of 2017 miles, another is the "3d" data points, which gives a length of 2032 miles, and finally the "warped" data points, giving a distance of 2174 miles, which is what I used to create the actual profiles.

Zip File

Here a link to a different version of the profile... as suggested by Tom Murphy Earlier. It doesn't have any labels, but the x-axis only goes up to 7000 feet, so the profile fills most of the chart. Unfortunately I can't increase the resolution much more because of software limitations... so it's the same resolution as the original AT profile that I posted.

profile without lables... different x-axis

[Mr. Parkay]

Help me out here... Exactly what is a layman's definition of "vertical exaggeration"?

The vertical exaggeration means that the y-axis has been stretched so that the climbs look steeper than they actually are. Otherwise the profiles would look flat on paper.... which wouldn't match up with our perceptions while hiking. That's my understanding anyway

[thirdeye66]

Thanks a ton Mr. Parkay.

I met you and your mother this year, not too long ago, at "the place" in Damascus. I purchased a bottle of Mr. Parkay shortly thereafter.

be well buddy.

-third eye

[Mr. Parkay]

Just a quick note:

I've recently created some more profiles for the AT... they are basically just smaller state-size profiles... probably more convenient for online viewing than the Huge Profile... Here's the link:

State Size profiles

if the above link dies... the profiles will probably be located on the main page of my website here.

[4eyedbuzzard]

Wow. A lot of time and hard work went into all that. Great resource for those of us who don't own full sets of maps. Nice of you to put it out there for all to use.

[JAK]

Just opened it with Foxit and it looks great. Thanks.

[Petr]

I'd be happy to post the "raw data" used to create the profiles. Although I'll need to explain some things first... since there are different levels of raw data depending on how much processing it has gone through. Here's an explanation about some of the data processing used:


1. The GPS track that I use is a modified version of the ATC's AT shape file .. which I have altered and processed in a whole bunch of ways to make the data more useful for my purposes. (I need to put a note about this on the profiles)

2. After modifying the GPS track I ended up with 104329 lat/lon points.

3. I used "Wissenbach Map" to add elevation to all 104329 data points.

4. Next I had to calculate the distance between each of the lat/lon points. For this I borrowed some python code, which uses Vincenty's formulae to calculate the "flat land" distance between points... This worked out to about 2017 miles.

5. I wasn't satisfied with the "flat land" distance, so I wrote some code which takes into account the "3d distance" added by mountains & such. It ended up adding about 15 miles, but I'm not a mathamatician, so my calculation could be off. This gives a total distance of 2032.7 miles, which is a lot different than the accepted 2174 miles that most of the guide books use. I'm not sure why the difference is so large, but I'm assuming that the 2174 number is a lot more accurate since it was probably calculated with a measuring wheel.

6. When I was creating the profiles I wanted the miles on the x-axis to match up with the distances that guide books use... since it would be confusing otherwise. To achieve this I wrote some python code which essentially warps the data points around "control points" that I have placed throughout the profile. I have about 100 control points, which seem to do a good job at altering the profile.

7. Then I use matplotlib to plot the data and create the nice looking pdf files.

The data in steps 4, 5 and 6 would all create slightly different profiles if they were plotted... although I prefer #6. Anyow, I'll generate some text files with this data and post it pretty soon. Perhaps it will be usefule if someone else wants to make some cool profiles!

Ummm...I am a mathematician (well, I majored in math in undergrad anyway), and I don't know what the ***** this guy is talking about. Anyway, very cool project, Mr. Parkay. Is this just a hobby or is this kind of work relevant to your profession?

Peter

[Petr]

Damnit, I should preview my posts. If there is any confusion, I meant my "don't know what he's talking about" statement to convey admiration and it was not intended to cast aspersions at this young gentleman's fine work. It seems like some could read my comment as questioning the validity of his methodology.