Mt Whitney Zone Forums General Discussion Gmap4 - Google Maps+topographic. View KML,KMZ,GPX,TPO

I have GPSBabel running on my server. Here is the command Gmap4 uses to convert GPX to KML:

gpsbabel -i gpx -f path_to_gpx_file
-o kml,points=0,line_width=5,line_color=990000ff -F path_to_kml_file
See Help file at p.12-13.

The above command converted your GPX file to a KML file that is 1.08 MB.
Note the parameter "points=0". If you do not include this parameter then each track point is also converted to a waypoint in the output file. Letting that happen greatly increases the output file size.

When you tell Gmap4 to display your GPX file, what you are really seeing is a KML file. Gmap4 uses GPSBabel to convert your GPX file to a KML file on the fly, temporarily hosts that KML file on my server, and displays that KML file on the map.

If you do the conversion to KML yourself, then you can edit the kml file and set your own line color, width, etc, etc, etc.

All is explained in plain English in the Help file. Be sure to download the KML files described in the appendix and read the comments in those files.

Just for reference, to post an embedded map of a specific location using Gmap4, (but without a gps trail file) here's how:

1.  First, you need to post using HTML, so you need to change the default "Markup" option (it is just below the text input window when you create a message) from  using UBBCode  to  using HTML and UBBCode.  It should be enabled, but if you can't find this option, send me a PM (click my name on the left).

2.  Copy this code into your post:
<iframe style='width: 800px; height: 600px; margin: 0' frameborder='0' scrolling='no' src=http://www.mappingsupport.com/p/gmap4.php?ll=36.578325,-118.292626&z=14&t=t2></iframe>

Change the "ll=" (Latitude/Longtitude) parameters to match the location you want to display.  Change the "z=" parameter to the zoom level you want. 15 is fully zoomed in, 14 zooms back one notch.

Post your message.

Below is what the code above will display.  You can use this map to find the area you want to display, since it displays the coordinates of both your mouse pointer and the map center.

To find another location, try these steps:
    Zoom out
    Click and drag the map so it shows the area you want
    Zoom in and re-center the map the way you want
    Right-click (at the center) to get a popup of the desired map coordinates
    Copy/paste the "Lat/Lon" map coordinates into your message.





To create a clickable link to the full-screen version, copy/paste the following line into your post:

[url=http://www.mappingsupport.com/p/gmap4.php?ll=36.578325,-118.292626&t=t4&z=14&coord=latlng]full screen version[/url]

You can change the lat/lon params to your area of interest. The "t=" and "z=" can be tweaked to change which map type and zoom-level you want initially.

Here's the result:   full screen version

I sure like this tool!

How about this for my instructions:

Steve! Help! Could you please post a co-ordinating map for me???!!!

Yeah, I'll do that for my friends, too.  

Gmap4 has acquired some new features since my prior post. Remember, Gmap4 is a 100% free no-ads map viewer that can display detailed topographic maps. There is nothing to download or install.

1. A powerful search feature has been added. Click Menu ==> Search. You can search on:
* Addresses
* Names of places and natural features
* Latitude Longitude (Geocache format and many others)

Here's an interactive map of the world:
http://www.mappingsupport.com/p/gmap4.php?ll=40.842415,-113.992258&t=t1&z=2.

Depending on what you are searching for, it may help if you include the name or abbreviation for the state/province/region. If you are searching for something in the USA or Canada then you can see the detailed topographic map by clicking Terrain ==> MyTopo.

2. Maps can be printed. In the menu bar for your browser click File ==> Print preview.

3. An icon can be placed at the center of the map. Here's an example. http://www.mappingsupport.com/p/gmap4.php?ll=44.460768,-110.828196&t=t2&z=14&icon=pgs

4. It is easier to get a copy of the URL that will reproduce the map you see on your screen. Click Menu ==> Map URL.
That URL can be used in a trip report, e-mailed, posted on a website, etc.

For more information please see the Gmap4 homepage where you will find examples, a change log and a detailed Help file.
http://www.mappingsupport.com/p/gmap4.html

Enjoy,
Joseph - Gmap4 author

Gmap4 has been updated to version 1.9.1 dated January 17, 2011. This version adds support for UTM coordinate grids. All UTM support in Gmap4 uses the WGS84 datum. This UTM support works worldwide. For more info on UTM coordinates see: http://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system

(Pay back time: When you visit other outdoor-related forums, please do a search and see if Gmap4 has been mentioned. If not, it would just take a moment for you to pass the word along. Also, are you doing the social network thing? Consider saying something nice about Gmap4.)

Here's a map of Grand Canyon Village with a UTM grid.
http://www.mappingsupport.com/p/gmap4.php?ll=36.059592,-112.139836&t=t2&z=14&coord=utm

To toggle UTM support on and off, click Menu ==> UTM On/Off. If UTM is 'on' then Gmap4 gives you UTM information in three ways:

1. A UTM grid is displayed. This UTM grid is displayed on both the MyTopo topographic maps (USA and Canada) and the standard views (aerial, etc) provided by Google Maps.

2. The lower right corner of the screen will always show the UTM zone and UTM coordinates for both the cursor and map center.

3. You can get the UTM zone and coordinates for any point on the map by right-clicking that point.

Things to keep in mind

You can build your own map links by using URL parameters. If you want your map to appear on the user's screen and already have UTM turned on, then add this URL parameter: &coord=utm

Here is a comparison:
With UTM on
http://www.mappingsupport.com/p/gmap4.ph...2&coord=utm

With UTM off (default)
http://www.mappingsupport.com/p/gmap4.ph...ek.kml&t=t2

If you zoom out far enough then you will not see a UTM grid. Instead you will only see vertical red lines which mark the edges of the UTM zones.

UTM grid lines that are near the edge of their zone often appear curved when displayed using the map projection used by Google Maps. The grid lines in the adjoining zone will curve in the opposite direction. For example, the next map is centered near Lake Tahoe. The red line marks the edge of adjoining UTM zones. Double click each side of the red line (this changes the map center) and watch the UTM grid lines change. The grid lines are calculated based on the UTM zone that contains the center of the map.
http://www.mappingsupport.com/p/gmap4.php?ll=39.115536,-120.208437&t=m&z=8&coord=utm

Some MyTopo topographic maps already have a UTM grid printed on them. Caution! Some of those printed grids are based on the older datum NAD27. Those older grids will have a uniform offset from the grid displayed by Gmap4 which is based on datum WGS84 . For example: Here is a map showing part of the Alpine Lakes Wilderness area in Washington State where the MyTopo maps have a UTM grid based on the WGS84 datum. Click Menu ==> UTM On/Off and you will see the faint UTM grid printed on the map:
http://www.mappingsupport.com/p/gmap4.php?ll=47.47229,-120.80588&t=t2&z=14&coord=utm

By contrast, here is a map showing part of the Yosemite Valley area in California, where the MyTopo maps have a UTM grid based on NAD27. Note the uniform offset between the two sets of grid lines.
http://www.mappingsupport.com/p/gmap4.php?ll=37.736733,-119.568449&t=t2&z=14&coord=utm

Usually (but not always) the different zoom levels use a different scale for the UTM grid. To learn the grid scale, compare the cursor coordinates (lower right corner) as you point to adjacent grid lines. If you want to know the zoom level, right click the map.

Maps with UTM grid lines can be printed. File ==> Print Preview

If you know of any other map viewing software that can display the MyTopo topographic maps along with a UTM grid, I would enjoy knowing about it.

Future UTM improvements

There are different methods for putting labels on the grid lines. I am pondering what will work best.
Another possible improvement is to let the user change the line width, color and/or spacing.
Other ideas?

Next Gmap4 update

Bad news: The 'Search' feature of Gmap4 no longer works very well for placenames. This feature uses Google's 'geocoding' service on the backend. OK, I admit it. Gmap4 was pushing the envelope in its use of that service. Whoops - Google pushed back. Guess who won? I will add a second search tool that is designed to work well with placenames.

Good news: The existing 'Search' feature of Gmap4 still works fine for searching on (1) anything related to addresses including names of many settlements that no longer exist and (2) any reasonable way to write a latitude/longitude pair.

Finally, if you find Gmap4 to be useful I hope you can take a moment and do some 'pay-back' by letting other people know about it.

Enjoy!
Joseph - Gmap4 author

Amazing work, Joseph. Thanks much for posting your information here.

...so when is Google going to buy your software?

Just a note: I changed "You can build you own map links" to "You can build your own map links"

Ok, Joseph, I need help!

Why won't my map above display using the file I have uploaded to this site?

...nevermind. There was a stray end-of-line in the middle of the iframe ... /iframe string.

The post was moved here.

Hi Joseph,

Is there a way to control the size of the displayed route?

I was successful in creating a map of a recent bike ride (huge victory for me ), but when opening the Gmap4 map the route is overpowering. See link.

Linky

Thank you,
John

Wow, TFC, I see what you mean!

I think, though, it is a function of all the way points you have in your file. Each one shows up as a little circle, so on the map that shows the entire loop, they are huge.

I went to your map, switched to satellite view, and then zoomed in all the way, and your route looks ok. ...but then I see you have a waypoint about every 50 ft!

Maybe Joseph can give us some hints.

Yeah, that's kinda ugly - no offense.

You get a star for using a KML file. A KML file can produce maps with much more info than a GPX file.

I opened your KML file and looked at its contents. You have a <LineString> tag followed by lots of coords. That's good. Those coords will draw the line you want to see on your map.

However, your KML file also has a gazillion chunks that look like this:
<Placemark>
<TimeSpan>
<begin>2011-04-03T08:00:43-07:00</begin>
<end>2011-04-03T08:00:45-07:00</end>
</TimeSpan>
<Style>
<IconStyle>
<color>FF00FFFF</color>
<scale>0.9</scale>
<Icon>
<href>http://maps.google.com/mapfiles/kml/shapes/placemark_circle.png</href>
</Icon>
</IconStyle>
</Style>
<Point> <altitudeMode>clampToGround</altitudeMode> <coordinates>-117.80387755483389,33.60310949385166,286.0</coordinates>
</Point>
</Placemark>

That's bad. The above KML commands add a marker to your map. Your KML file adds a gazillion markers to your map and that is what you seeing.

It looks to me like you want to start deleting lines with line 91. Be sure to keep any closing tags that you need at the end of your KML file.

When you made your KML file, here's what happened.
1. All your track points became a KML <linestring>. Good.
2. Each of your special waypoints became a <Placemark>. Good.
3. Each of your track points also became a <Placemark>. Bad! <== Can you turn that off in whatever software you are using?

Joseph

PS. The Appendix to the Gmap4 'Help' file has info on using KML files. That info includes template KML files that you can download and edit.

For example, you could grab one of the template KML files and then paste in your own <linesting> coords.

http://www.mappingsupport.com/p/gmap4_help.pdf

Joseph

Thank you for the reply.

The only reason I was successful in getting that far is because I didn't have to do anything.

I transferred data from my garmin gps (edge 500) to garmin's website and then exported from there straight to kml. I didn't manipulate the file at all.

I doesn't appear that garmin's website gives any choices when creating the .kml file. However, they do allow for .tcx or .gpx exports as well. Using a .gpx file directly exported from the garmin website works fine (just tested). Thus, I'll just use those or perhaps use google earth or the other programs mentioned in the help file to create the .kml file.

Thanks again!
John

I just promoted Gmap4 from version 1 to version 2.

Little reason: I added support for viewing the set of topo maps that used to be known as Terraserver and now are known as Microsoft Research Maps. Click the map type button in the far upper right and select "US Topo". You can really see the quality difference compared to the MyTopo maps.

The US Topo maps often load a bit slow. Part of the reason is that each map tile must be re-projected on-the-fly in order to match the map projection used by Google Maps. I added support for these maps in case they show old (abandoned?) trails that are not on the MyTopo maps.

Big reason: This update introduces a new text file format that makes it super easy to produce maps. For a quick look, scroll down a bit on the Examples page: http://www.mappingsupport.com/p/gmap4_examples.html

This new file format is so easy that middle school students can quickly learn how to produce maps.

In addition to the maps on the 'Examples' page, here's another example for those that would like to learn about this new text file format. This map shows the lower Mississippi River valley. Click the "i" icon near the upper middle for an interesting story.
To turn the symbol labels on/off click Menu ==> Labels On/Off.
http://www.mappingsupport.com/p/gmap4.php?q=https://sites.google.com/site/gmap4files/p/news/mississippi_course_change.txt&ll=30.417887,-91.201416&t=h&z=9&label=on

Here is the data file that produced the 'Mississippi' map:
https://sites.google.com/site/gmap4files/p/news/mississippi_course_change.txt

Maps produced with this new text file format can include:
* Many different kinds of symbols (i.e. markers/icons)
* Lines of any color and any width
* Balloons that appear when symbols are clicked
* Links in the balloons
* Clickable photo thumbnails in the balloons
* And more

Did I mention that this is truly easy?

For the details, you can search the Help file on 'delimited'. Or just go to page 32 in the 5-6-2011 version of the Help file. http://www.mappingsupport.com/p/gmap4_help.pdf

Homepage: http://www.mappingsupport.com/p/gmap4.html

Enjoy.

Joseph

Thank you, Joseph. I need to explore your new features.

Checking briefly, I zoomed in on the ranger cabin at Charlotte Lake in the Sierra, and switching between the map modes, it appears the US Topo version is offset ~100 M to the east.

Here's the embeded version: (click _here_ for full-screen)

How odd...

In order to get different map images for the same location to line up, both maps need (1) the same projection and (2) the same datum.

I know that MSRMaps/Terraserver and Google use different projections and I have taken care of that in the code.

But they both claim to essentially use the same datum (WGS84 and NAD83).

Here's a link to a random spot in north CA. The center of the map is a section corner. The two topo maps are almost perfectly aligned.
http://www.mappingsupport.com/p/gmap4.php?ll=41.524239,-122.709137&t=t3&z=16

I have checked a number of spots in several midwest states and they are also aligned correctly.

I'm going to email the staff working on MicrosoftMSRMaps/Terraserver and see if they can shed light.

There are some pretty bad map-joining problems with those "US Topo" maps in some areas. I started heading south on the map through Central Cal, and things get bad in some spots.

Check the mess in this area: Hensley Lake, east of Madera CA.

But please don't back out your new features. People can compare and decide which maps to use.

Yeah, I've seen the same in other CA spots.
But most places the "US Topos" are fine.

It took awhile but I finally found an email that I think will reach the MSRMap folks. I sent them some sample map links and asked if they could shed light. Here's hoping they reply.

Gmap4 has been updated to version 2.1.5 dated September 14, 2011. For a full list of the changes in this version please see http://www.mappingsupport.com/p/gmap4_whats_new.html

Remember, Gmap4 lives in the cloud and does not require you to download or install anything. Anytime you view a map with Gmap4, you automatically will be using the most recent version.

The big news is that you can now strap on a personal jet pack and fly around in 3D anywhere in the world. (The Gmap4 'Search' feature is a useful way to zip you to the spot where you wish to begin flying.) This feature runs Google Earth in your browser.

You can zoom in and fly over any map that has a GPS track (or other data) and see the world in 3D. No sweat, no bug bites, no blisters.

All you have to do is download the Gmap4 'Help' pdf file dated September 14, 2011 (or more recent) and search for 'Tips for flying'. Anyone can quicky and easily learn to fly with just a mouse by taking a quick trip through flight school by reading those tips. Those tips give you step-by-step instructions that will show you how to fly over the John Muir Trail in California starting from the summit of Mt. Whitney. This is ability to fly with a 3D view is easily the coolest feature in Gmap4.

Gmap4 'Help' file: http://www.mappingsupport.com/p/gmap4_help.pdf

For most people this updated version of Gmap4 works fine. However, a few people have reported that all they see when they try to use Gmap4 is a blank screen. If you are having trouble viewing maps with Gmap4, then I have a favor to ask. In addition to updating the code I also put together a short list of easy things that you can do to try and get the latest version of Gmap4 working on your system. Here's the favor: Please download the 'Help' file and search that file for 'tips on flying'. Near the end of that section you will see a heading that starts "Background...". That section gives you a peek under the hood and suggests several easy/quick things you can do to try and get the current version of Gmap4 working on your system.

Some of those suggestions have worked for others, so I hope if you are having problems that you take a few minutes and give them a try. And if nothing else works, then the last suggestion gives you a link to the prior version of Gmap4 that does not include the new 'Earth' feature which seems to be the source of most of the problems.

In addition, the 'directions' feature has been re-written. Right-click the map and then click either 'Direction from here' or 'Direction to here'. After the route appears, you can drag it to make changes. You can build a Gmap4 URL that will open with the directions panel displayed and the destination filled in. This will be useful for helping people obtain directions to a meeting spot. Search the Gmap4 Help file for 'Tips for using directions'.

Also, information on how to donate has been added to the 'Action' menu and the Gmap4 website.

Enjoy!

Gmap4 has been updated to version 2.1.6 dated September 17, 2011.
Homepage: http://www.mappingsupport.com/p/gmap4.html

Reminder: Since Gmap4 lives in the cloud (1) you never have to download or install Gmap4 and (2) you are always automatically using the latest version of the code. But if Gmap4 does not seem to work then please clear your browser's cache and try again. To see the Gmap4 version number you can click Menu ==> About on any map.

This update fixes the 'blank screen' problem that some users experienced after the September 12th update. If you experienced that problem, then please try Gmap4 again.

In order to use the new 3D 'Earth' view, your computer system needs to have the Google Earth browser plug-in installed. The Gmap4 code now checks to see if your system already has this plug-in installed. If your computer system does not have this plug-in installed, then you will see a message telling you that and a link to Google where you can download the plug-in if you decide to install it. If you decide to install the plug-in, please follow the instructions in that message. You need a broadband connection and a reasonably modern computer to use the 3D 'Earth' view.

Also, your security software might ask you to give permission before this plug-in will work.

If you decide to not install the plug-in, simply close the message window. You can continue using all the other features of Gmap4 except the 'Earth' view.