Gmap4 - Enhanced Google Map viewer with topographic maps

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RobFromRedland
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by RobFromRedland » June 18th, 2013, 7:47 am

Joseph

That is very cool! I figured there must be an "official" record of trails somewhere, although their data is not perfect. I found some missing pieces on some trails I know about. Most of them are there, though.

I'm curious now - is there a way to use this "basemap" data, and then supplement other (missing) data as a new layer or something using gMap? Maybe I shouldn't be posting questions like that here, but I'd like to know. If there is a more appropriate place to discuss this, let me know.

Thanks
Life is not a journey to the grave with the intention to arrive safely in a pretty and well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming: WOW-What a ride!

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » June 18th, 2013, 7:57 am

RobFromRedland wrote:I'm curious now - is there a way to use this "basemap" data, and then supplement other (missing) data as a new layer or something using gMap?
This is a great place for Qs since others can also benefit.

When I have checked trails that I have been on and seen where the WMS data and topo map disagree, usually the WMS data is more accurate. I believe over the last few years the USFS used paid staff and/or volunteers to actually walk/ride the trails and collect GPS data.

You can supplement WMS data by including either (1) a &q= parameter or (2) a &markers= parameter in your Gmap4 link.

'q' points to a data file that is online

'markers' is used to make a "map-in-a-link"

Joseph

RobFromRedland
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by RobFromRedland » June 18th, 2013, 11:12 am

That is very cool. I will have to experiment with this a bit. I checked some of the data on that map to actual GPS tracks I have and they look very similar, so I think you may be correct.

They are missing a good portion of the PCT!!!!

Thanks for posting it!
Life is not a journey to the grave with the intention to arrive safely in a pretty and well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming: WOW-What a ride!

raven
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by raven » June 18th, 2013, 11:40 am

As to the differences between USGS-drawn trail positions and actual modern locations, it's not only a matter of accuracy. Many trails have been relocated, some several times. Trails have been moved out of meadows, had switchbacks added, have been rerouted after slides, etc. The new database is likely to keep routes current, but some mapped routes are probably still there to be found, if you look carefully.

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » February 17th, 2014, 7:37 am

Yesterday I updated the Gmap4 production code. You can now overlay topo lines on the aerials.

For more info please see: http://www.mappingsupport.com/p/gmap4_whats_new.html

For example:


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BrianEdwards
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by BrianEdwards » February 17th, 2014, 8:53 am

Great job Joseph, I'll be putting this new map through its paces soon
Clackamas River Waterfall Project - 95 Documented, 18 to go.

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » July 1st, 2014, 7:28 am

I just posted a beta release for Gmap4 version 6.0

For a link to the beta code and a list of the new features, please see
http://www.mappingsupport.com/p/gmap4_beta.html

One new feature with great potential for further enhancement is Menu ==> My location. This geolocation feature is meant for smartphones and other mobile devices.
1. The location symbol now follows you as you move just like a regular GPS.
2. If you touch the location symbol then your coordinates are displayed using the current format you have selected. The default coordinate format is decimal degrees.

This link will start the beta code and show your location on the high resolution topo maps:
http://www.mappingsupport.com/p/beta/gm ... on=on&t=t4

Joseph

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer - Works offline!

Post by Joseph Elfelt » September 25th, 2014, 6:50 am

Up until this summer I believed that Gmap4 would not work if your mobile browser was offline.

I was wrong.

If you follow a few simple instructions, many (but not all) of the Gmap4 features will work just fine on a smartphone, tablet or other mobile device when you are offline. Among other things, when you are offline you can:
* Look at high resolution topo maps (t4 Topo High)
* Look at Google aerials
* Look at other basemaps
* Look at GIS overlays
* Turn on the geolocation feature (Menu ==> My location) and see the map become centered where you are standing
* Move and watch the location symbol follow you and the map automatically move as needed
* Touch the location symbol and see your coordinates in the current coordinate format
* Change the coordinate format
* Turn on/off a UTM grid
* Turn on/off a USNG grid

Yes, you can do all of the above while you are offline. Now let’s pop the hood and see how this works.

Any map you see with Gmap4 consists of a bunch of small image files called “tiles” that are stitched together to cover your screen. When you look at a map while you are online, a copy of each image file is saved in the browser’s cache. If you keep the browser tab open that has the Gmap4 map, then you can then go offline and still pan the map over the area for which there are map tiles in the browser’s cache. If you pan too far, the screen will be white.

To read plain English instructions that I guarantee you will understand (I don’t know how to write computer babble-speak) please visit the Gmap4 Help page and download the pdf file “How To Use Gmap4 Offline”.
Help page: http://www.mappingsupport.com/p/gmap4_help.html

Joseph

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » January 17th, 2015, 7:07 pm

I just posted Gmap4 v.7 beta.
You can check it out on the beta page:
http://www.mappingsupport.com/p/gmap4_beta.html

The first example map displays GIS recreation symbols for all the national forests and lets you click a symbol and see all the GIS attribute data for the feature you clicked.

To the best of my knowledge this is a unique feature for any software that is based on Google maps.

Joseph Elfelt
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Re: Gmap4 - Enhanced Google Map viewer with topographic maps

Post by Joseph Elfelt » February 6th, 2015, 5:11 am

Gmap4 was recently updated to version 7. The big-impact new feature is the ability to display attribute data from GIS servers. A person viewing a Gmap4 map that shows GIS data can click on a GIS symbol and a popup will appear that displays all the attribute data that the GIS server has for the thing that was clicked.

For example, here is a map centered on NW Oregon that shows public land. Click on any of the colored areas to see the attributes. This public land data comes from a GIS server operated by the State of Oregon.

http://www.mappingsupport.com/p/gmap4.p ... undary.txt

Here is another example. The following map displays symbols for recreation opportunities (campgrounds, trailheads, etc) on most of the national forests. For this demo the map is zoomed in on an area of the Mt Hood National Forest. The data that puts the symbols on the map comes from a GIS server operated by the Forest Service. It may take a few seconds for the red symbols to appear. Click any red symbol to see all the attribute data.

http://www.mappingsupport.com/p/gmap4.p ... eation.txt

The attribute data you see on the above map includes a link (RECAREAURL) that will take you to a web page the Forest Service maintains with more details about the thing you clicked.

Click the “About this map” link in the upper left corner of the map to learn how to turn other GIS overlay layers on and see their attribute data. Among other things, you can display a GIS layer for Forest Service roads that allow motorized use and a different GIS layer for roads that are closed to motorized use. If a road is hard to see then change the basemap to “All white basemap”.

For more Gmap4 links that display recreation-related GIS data, including attributes, you can visit
http://www.propertylinemaps.com/p/public_land_map.html
There are several map links that display GIS data layers for Oregon and also Washington. There is also a map that shows the current USA weather watches and warnings. If you click on any of the colored areas then the attributes include links to weather service pages that have all the details.

Finally, every attribute popup always has a link titled “GIS server directory”. This link takes you straight to the GIS server that includes the data layer that is presently displaying attribute values on the map. A new Help page (http://www.mappingsupport.com/p/help_fi ... _help.html) walks you through (1) understanding the key information the GIS server directory provides and (2) how to use that information to build your own custom Gmap4 links to display the GIS data that *you* want to see.

Joseph, the Gmap4 guy

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