Gmap4 - Enhanced Google Map viewer with topographic maps

Cartography, maps, navigation, GPS and more.
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Splintercat
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Splintercat » April 10th, 2013, 9:53 pm

Joseph, just catching up this thread - nice work! Made the topic sticky since it has been around for awhile.

You might have explained this already, but is the trail data for Mt. Hood NF from the Forest Service? It looks to be digitized USGS data, but still very handy. I also noticed that a "certain" favorite trail of mine was added to the database in 2010, so thus my question about the source. Thanks!

Tom :)

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » April 11th, 2013, 5:32 am

Thanks for the 'sticky' Tom.
Also the new 'Maps and Nav' is certainly a better home for this thread.

The t2, t3, t4 and t6 maps all began life as scans of paper USGS 1:24,000 quads. These maps only show whatever was on the paper quad that was scanned.

The t3 maps will sometimes be older. Occasionally I have seen trails on the t3 maps that do not show up on the other maps.

The t4 maps are supposed to be scans of the most-recently-published paper quads. In some parts of the US the most-recently-published paper quads are still quite old. The USGS has gone digital and no longer publishes paper quads. Alas, some of these t4 scans (which were done by the USGS) resulted in the color green (forest cover) being turned into various shades of yellow. I suspect poor quality control during the scanning process.

The t8 maps that recently were added to Gmap4 are based on Open Street Map (OSM) and include crowd-sourced trails and topography.

Yesterday I noticed a bug in the new map-in-a-link feature. That will get fixed later today.

Joseph

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Splintercat » April 11th, 2013, 7:06 am

Thanks, Joseph -- my question is pretty specific: I'm wondering how a trail segment like this got into the database:

Image

I first noticed it on a USFS fire map created at the time of the Dollar Fire, as shown here:

Image

Thrilled to see it, because this particular trail had dropped off the USFS maintenance list decades ago, but now I'm wondering what this data set actually represents. Is this their official asset inventory -- and are the attribute fields part of a USFS database (e.g. the trail name, number, length, etc)?

Tom :)

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » April 11th, 2013, 8:03 am

@Tom

At the bottom of this post is a live Gmap4 map displaying the hi-res topo centered on the trail you marked.

The first image in your post came from a Gmap4 map produced by Chico. I don't think he has registered in this forum. Chico is a GIS professional and also maintains the website for the Olympia WA chapter of Backcountry Horsemen. He has produced a large number of Gmap4 links that display trail data that is maintained by the USFS as GIS shape files. Chico converts those .SHP files to .KMZ files, does any cleanup work that is needed, posts those KMZ files online and builds Gmap4 links to display those files.

To check out Chico's map links, start at http://capitolriders.org/ and follow the link for maps.
He is working his way through the national forests in the western US.
It looks like he has finished the national forests in Oregon.

Alas, I have no insight as to why the USFS decided to include the trail segment you marked in its GIS database.


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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » June 14th, 2013, 8:12 am

Many of you already know that Gmap4 is a general purpose file viewing tool for GPX, TPO, KML, KMZ and a couple of other file types.

I just posted beta code that lets Gmap4 also be a general purpose WMS viewing tool. Why might you care? At last count there were approximately 1.2 bazillion WMS servers out there and this beta code can display most of that data. Specifically, you can:

* Build a Gmap4 link to display multiple layers from multiple WMS servers
* Turn transparent layers on/off one at a time or all together
* Change the stacking order of transparent layers
* Display transparent layers on top of any basemap hardcoded into Gmap4 or on top of any basemap added via WMS

As a software developer, it is always exciting to develop a feature that is first-of-its-kind. If there is any other software that lets you "click link - see WMS data", I would like to know about it.

The Gmap4 beta page has examples and documentation:
http://www.mappingsupport.com/p/gmap4_beta.html

The example maps include:
* Detailed boundary of federally owned land
* NOAA coastal navigation charts
* Index to 1:24,000 scale topos
* Current forest fire boundaries
* and more

There might be some kind of limit as to how complex(?) these maps can be. Gmap4 uses the Google map API but Google’s docs do not mention any such limit.

I would enjoy seeing any cool way you use this feature and I am happy to answer questions.

Joseph, the Gmap4 guy
Redmond, WA

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » June 17th, 2013, 1:55 pm

Update June 30, 2013

The USFS took down the trail data that this map displayed.

In trading email with a server admin at their HQ I learned that this trail data has not yet been fully blessed for public release.

I lobbied in favor of a phased approach to making this data public. Since the trail data for Region 6 (WA and OR) is in reasonably good shape, that data should be placed online even though the trail data for at least some other FS regions might still need a fair bit of work.

This guy also gave me a great tip that led to an undocumented feature in ESRI ArcServer. The upshot is that I will be able to make Gmap4 into a general purpose GIS viewer for data that is available via either the WMS interface or REST interface.

----------------------------------------------------------------

I’m still wrapping my head around the possibilities that come from being able to display almost any data hosted on WMS servers. It turns out that sometimes the hard part is simply finding the address (‘endpoint’ in GIS-speak) for the server.

Yesterday I stumbled across a WMS server run by the USFS with the catchy name:
http://apps.fs.fed.us/ArcX/services/wo_nfs_gstc/GSTC_IVMRoadsAndTrails_01/MapServer/WMSServer

Whadayaknow! This is where they tucked away all the national forest trail data for the USA. The beta version of Gmap4 can display all of this trail data.

I tried to embed this map but the foum software choked on the complex link. Reminder - this map is produced by the Gmap4 beta code.

<Edited to add a layer with recreation symbols. Zoom in and you see the names of trailheads.>

http://www.mappingsupport.com/p/beta/gm ... ation_site

If you zoom in on the map then you will see trail numbers. If you zoom in more then you will see trail names. To easily read the trail names, change the basemap to ‘All white basemap’.

To change the overlays that are turned on and their stacking order, open the 'map type' menu by clicking 'T1 Terrain' and go to the last part of the dropdown menu. A higher numbered overlay covers up a lower numbered overlay.

Try this: Turn off all overlays.
Turn on mountain bike overlay
Toggle the non-motorized overlay back and forth

I panned to a random forest in Montana and got the same data.

To get the link that starts this map, click Menu ==> Link to this map.

Joseph, the Gmap4 guy
Last edited by Joseph Elfelt on June 30th, 2013, 6:08 am, edited 2 times in total.

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Don Nelsen
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Don Nelsen » June 17th, 2013, 4:11 pm

Joseph,

Thanks so much for this wonderful resource! It has been a great help in many of my adventures and explorations.

dn
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"If you don't do it this year, you will be one year older when you do" - Warren Miller

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by BrianEdwards » June 17th, 2013, 5:50 pm

Now that is just cool. Seeing the official trails laid out on a terrain map. Thanks again Joseph
Clackamas River Waterfall Project - 95 Documented, 18 to go.

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » June 17th, 2013, 6:41 pm

Thanks for the kind words.

Can someone please look at that map and then change the basemap to "Earth" so their Google Earth browser plugin starts? Are the trail overlays still visible after 'Earth' view starts?

For some unknown reason I am having trouble making my Earth plugin work. :(

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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by kepPNW » June 18th, 2013, 6:33 am

Joseph Elfelt wrote:Can someone please look at that map and then change the basemap to "Earth" so their Google Earth browser plugin starts? Are the trail overlays still visible after 'Earth' view starts?

For some unknown reason I am having trouble making my Earth plugin work. :(
Nope, no trails with GE, here either. (FF v20.0)
Karl
Back on the trail, again...

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