SummitPost.org

Found by coincidence on the net :
http://www.geocontext.org/publ/2010/04/ ... 3782221303
source of inspiration ?

Day Hiker wrote:. . .

Here is an updated gpx file for Funeral Peak: gpx file

I deleted the old one.

mrchad9 wrote:Thanks MoapaPk, but now the route is in reverse, and for some reason it thinks the low point elevation is zero. But I least the highpoint is correct.

Maybe I will play around with it and see if I can splice the original and old one together in a way that will work.

Yes, I added a few points that were automatically set to zero elevation. Normally the assigned elevation either comes from the elevation recorded by the gps, or that elevation given by the digital elevation model used by the mapping program (which will use the gps x,y and interpolate the z in a table). That particular app has no DEM table, so it assigned 0. Sorry about that, I forgot that we were now doing elevation profiles.

Matt, have a look to this link :
http://www.mappingsupport.com/p/gmap4.html

Matt,

I am the author of Gmap4, the program that visentin mentioned. Thanks for remembering about me visentin.
I started this thread: http://www.summitpost.org/phpBB2/viewtopic.php?p=696113

Irrespective of whatever software or map engine is used, I think it is fantastic that more and more outdoor oriented sites are including maps with GPS data.

I noticed that you are using version 2 of the Google Maps API. Since you likely know that Google has deprecated version 2 and is now promoting version 3 of the Google Maps API, I'm curious why you decided to use v2.

<edit>One new feature available in v3 (and not v2) is the ability to print maps right from your browser. Anyone can try this. Below is a link to a world map. Click Menu ==> Search. Include something like a country/province/region/state name in your search. When you find what you are looking for, try telling your browser to print a map.
http://www.mappingsupport.com/p/gmap4.p ... 5&t=t1&z=2
</edit>

I've been thinking about visentin's suggestion of adding an additional map view based on the country for which data is being displayed on the map. Now that is an intriguing idea. It is also an idea that I have not seen implemented anywhere. Looking at that idea with a 30,000 ft view, two things would be required.

1. The program would have to be able to find out the country in which the points in a data file (GPX, etc) reside.
2. The program would also need to define a custom map type for that country's maps (assuming some exist).

Google's geocoding service can easily do #1. Just extract the first coordinate from the data file, send it to Google, and Google sends back the name of the country.

For #2, turn to the savvy volunteers here. I can provide the javascript code for topographic maps covering the USA and Canada.
Just a thought....

Oh, and to see examples of trip reports with embedded 'live' Gmap4 maps showing GPS data, you can search the "Trip Reports" for posts that include "Gmap4" on this site: http://www.nwhikers.net/forums/search.php
These maps run in iframes. The site boss is allowing iframes just for Gmap4.

Finally, have you thought about allowing people to upload KML files so that they can include photo links on their map?

http://www.summitpost.org/piz-pal-trave ... map/694125

The GPX route appears as flat !

visentin wrote:http://www.summitpost.org/piz-pal-traverse/gpx-map/694125

The GPX route appears as flat !

The GPX file contains no elevation data. I'm guessing the file was created with a mapping program (not taken directly from an actual GPS), and the mapping program did not assign a elevation to each point. the file has trackpoints like:
<trkpt lat="46.374740000" lon="9.930140000">
<ele>0.000000</ele>

MoapaPk wrote:

visentin wrote:http://www.summitpost.org/piz-pal-traverse/gpx-map/694125

The GPX route appears as flat !

The GPX file contains no elevation data. I'm guessing the file was created with a mapping program (not taken directly from an actual GPS), and the mapping program did not assign a elevation to each point. the file has trackpoints like:
<trkpt lat="46.374740000" lon="9.930140000">
<ele>0.000000</ele>

You're guessing correctly. I created the map using wandermap, and didn't even know about the GPX feature until Eric pointed it out to me. On the wandermap site, the route has an elevation profile. If you want to look at it, here is the link: http://www.wandermap.net/route/799435

Mind you, from looking at google earth and google maps, I've learned that the altitudes given are not particularly accurate. That's not wandermap's fault, it's the underlying map data. I find that real topo maps are much better in general, and this is true for the Bernina area too. Therefore, even if wandermap had included altitudes in the GPX file, they would have to be taken with a grain of salt.

I had a close look at the elevation profile. It seems that wandermap has some trouble staying on the ridge. Sure, it's a knife edge, but even on the big central summit, the profile is incorrect. The two most noticeable errors are the drops in elevation just east of Piz Spinaz, and even more pronounced the unreal drop just east of Piz Palü East. Given these gross inaccuracies, I believe it's better that the altitudes are omitted in the exported GPX file.

Rob

rgg wrote:
I had a close look at the elevation profile. It seems that wandermap has some trouble staying on the ridge. Sure, it's a knife edge, but even on the big central summit, the profile is incorrect. The two most noticeable errors are the drops in elevation just east of Piz Spinaz, and even more pronounced the unreal drop just east of Piz Palü East. Given these gross inaccuracies, I believe it's better that the altitudes are omitted in the exported GPX file.

Rob

Many mapping programs use a digital elevation model (DEM, essentially a big 2d array of z(x,y)) that is substantially coarser than the topo map, and use a process like splining to interpolate intermediate values. These coarse, interpolated models may see a very sinuous ridge (in x,y) as being a much more like a smooth parabolic-cross-section surface. Thus a sinuous x,y path -- which in the extreme, could be staying exactly on the ridge at one elevation -- is forced artificially to drop down to one side or the other of the model surface. The result is a bizarre overestimation of accumulated gain and loss on the ridge.

Google earth gives the option of picking a fine DEM, which in the USA and parts of Europe, is often very close to a 3x3 meter grid.

MoapaPk wrote:Google earth gives the option of picking a fine DEM, which in the USA and parts of Europe, is often very close to a 3x3 meter grid.

Apparently, wandermap uses a courser grid. I don't know how I could can create a route with a higher resolution than what wandermap uses by default.

I regularly use Google Earth when trying to determine where I took a certain photo and what peaks I´m looking at. As it happens, I downloaded a new version of Google Earth last weekend, and noticed that I could choose the resolution that I wanted. I presume that that's what you are referring to. I set it to maximum, only to find out that my computer got stuck - either my computer wasn't fast enough, or version 6 is slower than the previous one. Mind you, Google Earth warned that a higher resolution would make things slower. Anyway, I couldn´t work with it like that, so I reset the resolution to its default value again.

The route profile doesnt' show up :
http://www.summitpost.org/the-ghosts-of ... ras/707688

http://www.summitpost.org/the-ghosts-of ... map/707688

That's an outrage! Have you tested it else where?

Josh Lewis wrote:That's an outrage! Have you tested it else where?

Yes I did.
Indeed I suspect the real reason to be that my object is a TR. How did I attach a GPX to a TR ? created a route first and changed it into a TR. I wonder if I can attach this way a GPX to an area or a FAQ or a picture !

I didn't ever have to do that to attach a gpx file to my trip report:
http://www.summitpost.org/in-awesome-wonders/699507
And Yes there is a road that cannot be seen on the route which is why it appears off the road on what you can see for the beginning.

I don't even have a gps. Ok so what I did was use google earth and then converted it, worked pretty well.

MoapaPk wrote:

visentin wrote:http://www.summitpost.org/piz-pal-traverse/gpx-map/694125

The GPX route appears as flat !

The GPX file contains no elevation data. I'm guessing the file was created with a mapping program (not taken directly from an actual GPS), and the mapping program did not assign a elevation to each point. the file has trackpoints like:
<trkpt lat="46.374740000" lon="9.930140000">
<ele>0.000000</ele>

I uploaded my first GPX file but it is not working on SP. I get the same error message above but the map does not appear at all. The GPX file works on other mapping software programs though, like OpenStreetMap.

Is there a way to fix this??

http://www.summitpost.org/mount-rogers-trail/716327