Possible to import PDFs to Google Earth or Basecamp?

Discussion in 'Mapping & Navigation' started by dieselcruiserhead, Apr 2, 2012.

  1. dieselcruiserhead

    dieselcruiserhead Long timer

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    Hi guys,
    The Utah BLM issues electronic maps of regions in PDF format. There is a specialty PDF feature specifically for mapping because there appear to be two layers to the electronic maps - the map itself, and then the trails layered on time. The maps and PDFs appears to be geographically relevant/consistent as there is a tool in the PDFs called "Geospatial Location Tool." I have full versions of Adobe Acrobat as well so I'd love to see if I can somehow export just the tracks, and place them into Google Earth without having to manually draw them using screenshotted image overlays.

    Anyone know if this is possible?

    Here are the maps in case: specifically this one (link to the PDF):
    http://www.blm.gov/pgdata/etc/media...avel_management0.Par.63789.File.dat/map_5.pdf
    Note how the PDF opens as two layers. This is more noticeable if you are on a slower computer, or as you navigate around the map.

    And here is a link for all of the Moab area maps in different sizes, just FYI.
    http://www.blm.gov/ut/st/en/fo/moab/recreation/motorized_routes/copy.html


    Man would that be cool if I could import those tracks into Google Earth or basecamp...


    thanks!
    #1
  2. mcnut

    mcnut Long timer

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    I think you can do what you are wanting but not as directly and possibly not with the desired outcome.

    Never have seen where .pdf can be imported but some mapping software (BaseCamp, GPSUtillity, and others) can import .jpeg, .jpg files. Not a expert but you might be able to convert the .pdf to a .jpeg with free image software such as IrfanView or by scanning a hard copy.

    The next step is a little harder as the .jpeg image needs to be scaled and located in the real world, this is called georeferencing and involves using at least 3 known locations (you need to provide Lat & Lon, maybe Alt) on the image (peaks or summits work well) which are spread out and form a triangle. Once done the map image now has a place in the world. It should be noted that while similar, geotagging a photo is different as it is only a point location.

    Once a map image is georeferenced it can be displayed by some software and even by some GPS units but the maps are an image and will not contain some of the function we have become accustom to like a POI database and auto-routing.

    Fairly sure MapSource can not do georeferencing, not sure about BaseCamp. I do know GPSUtillity and OzyExplorer can but they don't do Garmin Maps like CN or Topo.

    Bruce
    #2
  3. dieselcruiserhead

    dieselcruiserhead Long timer

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    That is what I've been doing (converting the PDFs into JPGs) but it is a F'g bitch and is taking forever and is very hard to get 3 points correct based on my knowledge or ability. Some are very close to lining up but some images where there are not strong geograpic points such as river to line up are not working so well.


    When you physically load the PDFs (I mentioned it before) but the trails load first, and then the background mapping. I know there has got to be some software that uses or imports this but I don't have it and it may be professional grade and out of my budget. That said I was over at a friend's house who is a professional GIS mapper and he didn't have a solution.

    I could make some calls to the Ranger station and see if I could get the trail maps in GPX or KMZ format but it would require someone really helpful and we leave tomorrow so I think for this section we're limited to what I drew with the JPGs and I'll just map it, old school style. Unless someone has a plugin or some other advice on getting the PDF into Google Earth or Basecamp or some other reasonably priced software. I do have a full version of Acrobat, as I mentioned. Maybe I'll experiment with this and see if it can maybe do a layered export...

    thanks
    #3
  4. wbbnm

    wbbnm Long timer

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    We have been putting BLM files into BaseCamp for New Mexico. I haven't done one for a couple of months, but here is what I sort of remember I did.

    Open the map and display it as a pdf in an Explorer window
    I usually only display about half or so of the original in order to get adequate resolution
    Then do a screen dump (control-Print Screen) to a bmp file,
    I use Paint to convert the bmp to a jpg and crop out non-map stuff,
    Then load the jpg into Google Earth. GE has tools for georeferencing the file, i.e. sizing and locating it such that the jpeg file correctly overlays the real world. You have to pick roads and/or boundaries to get it right. As noted above it can be tedious.
    Then use GE to create a KMZ file.
    You can import the KMZ into BaseCamp.
    Then when you are creating a route or track you can move the BLM map into and out of your work area.
    #4
  5. HogWild

    HogWild Scott Whitney

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    That's pretty much the way I do it too. But I don't use MapSource or Basecamp. Once I have the image positioned in Google Earth (or before), I make it semi-transparent, then draw GE "paths" over the roads I see in GE that line up closely with the lines on the overlay map. Often the map can't be lined up perfectly across the area, so I have to adjust its position a few times as I'm drawing the paths. Once I've drawn the paths, I save the paths to KML and convert to GPX. Then I open that in MapSource and change the colors of the tracks to what I want.

    I don't know of any tool that can pull the line data out of a PDF to form tracks. Best bet is to get the original data from BLM that they used to create that map. Someone there probably has it all in some form of GPS file. They should publish that file right along with the map image!
    #5
  6. FixerDave

    FixerDave KLR650 - XR200R

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    In the linux word, there are things like PDFedit, but even if you could isolate the tracks, then what? I don't know of anything that could convert them to any kind of standard mapping format. Yes, the best bet is to get the original vector data... the PDFs are for people that don't know what to do with vector. Canada has a website that goes to scanned PDF maps and other sites that go to online mapping resources that allow you to to see vector data of your choice overlayed in various ways. But, if you dig, you can find the CanVec maps, which are the source of all of this. Pure vector data, free. Your BLM probably offers something similar, if you know where to look (no, I don't).

    Other than that, have you looked at Open Street Map (OSM)? Now, once you get into that ecosystem, there are amazing options for vector or raster output. Around my area, OSM has all the CanVec data, and a lot more that's been entered by people just mapping for fun. I just did my first upload the other day, added in a route over a mountain that I rode last year and that was missing from the mapping data. The next day, there it was for everyone. OSM is the way forward. It is possible now to generate Garmin maps from OSM data, though - as far as I know - it's still technically challenging. I would not be the least bit surprised to see OSM->Garmin one-click tools within a year. Tools that anyone can easily use.

    Even though it's actually fairly easy to render a PDF to an image (use GIMP instead of screencaps - more here: http://gpsdave.blogspot.ca/2010/02/geo-referencing-pdf-maps.html), georeference them in Google Earth, and then trace out the tracks you want, I recommend you go the OSM route instead. Long-term, you will be farther ahead.

    David...
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  7. abhibeckert

    abhibeckert Long timer

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    This doesn't sound like it could ever work well, unless the pdf happens to be in the exact same map projection as google earth or basecamp (what projection does basecamp use anyway?).

    There are (literally) hundreds of techniques for taking a planet shaped area (the earth, which is not actually a sphere even if you ignore mountains and valleys) and projecting it on something flat like an LCD monitor or a sheet of paper.

    Every single one of these projection methods is bad for one reason or another (for example, google maps distorts so bad the further away from the equator you get, it makes antarctica look like it's twenty times bigger than australia, when australia is actually the larger continent - depending how you classify the glaciers).

    If your pdf or jpeg doesn't use the same projection as the map, you can pretty much forget about overlaying it onto another map in any meaningful way. You can get one single point of the pdf in the right spot, but every other part of the pdf will be wrong.
    #7
  8. dlh62c

    dlh62c Long timer

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  9. dieselcruiserhead

    dieselcruiserhead Long timer

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    OK, I guess it's mostly bad news but good news on GIMP as a tool to convert it. I was attempting to use a screengrab tool and it was having issues converting PDFs into a large single image. In hindsight perhaps I should have tried photoshop.

    Anyway, thanks.

    I did check some of my hand drawn tracks from the overlays this last weekend and I was off in quite a few places.

    So it is definitely difficult and time consuming, particularly considering someone already charted the exact GPS coordinates into the PDF.

    thanks
    #9
  10. OneEffinName

    OneEffinName Been here awhile

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    Yeah what he said. Do it once and it will become very fast. Works quickly and with anything. I use it ALL the time.
    #10
  11. MrMac

    MrMac Been here awhile

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    GlobalMapper (http://www.bluemarblegeo.com/global-mapper/index.php , ~$400 retail) has the capability to convert GeoPDFs to GeoTiff (and other) images which should be directly importable to about any mapping software. Although the PDFs from BLM are supposedly GeoPDF, I have not been successful in using them with the free Terrago GeoPDF toolbar (http://www.terragotech.com/) or my older version of Globablmapper, so I'm not sure what the problem is. I need to do some more testing when I can get to another computer with current software..

    There is also G-Raster: http://moagu.com/?page_id=155 which I have not tried yet, but will look into it soon..!

    Just an FYI, all current and historical USGS quad maps are now available free to download as GeoPDF from http://store.usgs.gov.
    #11