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Map coordinates to GPS

Discussion in 'GPS Stuff' started by hardman, Jan 21, 2012.

  1. hardman

    hardman ODSC-OFTR Member

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    I use the "Backroad Mapbooks" up in crown land regions for riding (Algonquin area). The new editions are now to scale in topo UTM.
    Many of the logging routes shown in here have no road names, so if I'm traveling these roads I don't want to miss a turn or intersection.

    If I use mapping tools to find the coordinates on the map and punch them into my Garmin, while riding the Garmin should than let me know this is the proper intersection to turn.

    Is this the correct way to do this or is there an easier way? :?

    Thanks
  2. Canadaler

    Canadaler ODSC-OFTR Member

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    Sounds reasonable.

    You can do the same for marine navigation. As long as your map measurements and calculations are correct you shouldn't have any problem.

    The other thing you can do is use Google Maps (satellite view) or Google earth in conjunction with your back roads map to identify feature/trails/intersections on the computer then just read out the Lat/Long coordinates.
  3. DualSport

    DualSport Ride Organizer

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    One way to do this is to scan your paper map to a JPG file. Load the jpg into Google Earth, change to UTM coords, then stretch/rotate the jpg until it matches Google Earth. At this point you can then just create waypoints at intersections, etc and export them to your GPS. If you have a Garmin 62 or 78, an Oregon or a Montana you can actually load the geo-coded JPG into your GPS as an overlay map. (I demo'd this at the Mohawk on Wed).

    Another way is to use the scanned map JPG, and load it to TrackMaker (free download). Calibrate the image with 2 known waypoints and then Trackmaker treats it as a GPS map and allows you to make waypoints, routes and tracks. It also interfaces with all the common brands of GPS to transfer the data (but NOT the map).

    Bob
  4. Randy_K

    Randy_K Limited User

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  5. DualSport

    DualSport Ride Organizer

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    It would but they are VERY expensive and are locked to one GPS.
  6. Randy_K

    Randy_K Limited User

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    I have a GPS on both bikes, they want me to buy a copy for each bike ? Are they nuts ?
  7. hardman

    hardman ODSC-OFTR Member

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    Great info here.

    I like the idea of using Google Earth with the Backroads Mapbook to find the coordinates. Not sure about actually loading up the jpeg, that seems kind of complicated but will check out TrackMaker .

    Some good ideas, many thanks. :D

    Hardy
  8. DualSport

    DualSport Ride Organizer

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    It's not as complicated as it sounds. I did it by following the instructions on the Garmin website when I tried it out on Ross's Garmin 62S GPS.

    http://www.garmin.com/us/products/onthetrail/custommaps

    Bob
  9. dean.f

    dean.f ODSC-OFTR Member

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    I also followed the instructions on the garmin website for my 62 but find it very difficult to align the image correctly is there some trick to doing this? its almost as if the scale is different from the google map to the backroad mapbooks image.
  10. hardman

    hardman ODSC-OFTR Member

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    I just reviewed Garmin's website re loading custom maps into the units, unfortunately my unit the eTrex LegendĀ® HCx is not compatible.

    What a bummer! :(

    Now I find out what I can't do with my unit, ha!
  11. MikeF

    MikeF ODSC-OFTR Member

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    Same here... I found it impossible to align the image to the map, even using major roads and intersections as alignment points. I eventually gave up. (FWIW, I was trying to overlay Pennsylvania State Forest maps)
  12. DualSport

    DualSport Ride Organizer

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    I don't have the Backroads mapbook but I think Hardy mentioned that they use the UTM datum. Most GPS, and the default on Google Earth, use WGS 84 so I'd set GE to UTM (Tools/Options/Show Lat-Lon=UTM).

    Aligning the JPG and GE is difficult if there aren't any prominent fetures in that area, especially if it's heavily wooded and the roads aren't very visible from the satellites. A trick I use, is to create a few waypoints for a few intersections near the corners of your paper map, and save them to a GPX file. Load them in GE as well as your JPG. It's then quite easy to drag the JPG to align with the waypoints.

    Bob
  13. DualSport

    DualSport Ride Organizer

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    Try it again with a smaller map. The PA State Forest maps (i.e. the PDFs from the PA DNR) are impossible to geo-calibrate, and I think it's because they cover too large an area. The actual land surface is obviously curved (the Earth is round, right?) but the PDF image is flat. I can get the top left section of the Tioga Forest map aligned on GE, but as I move across the map to the bottom right corner the errors increase. The solution is to break the map image into smaller sections and get a good calibration on each, and then load multiple sections.

    Another solution for your particular interest is to ask for a copy of my PA Forest Roads Map :wink: . It's a transparent overlay map of all the roads on the DNR maps which are designated as "Driveable Trail", and it loads on your GPS and shows over Navigator, Topo or whatever is your main map.

    Bob
  14. dean.f

    dean.f ODSC-OFTR Member

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    Thanks for the advice Bob I will give it another try.
  15. DualSport

    DualSport Ride Organizer

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    Here's an example of a practical application for converting paper maps to a GPS map. The OFTR hand out this paper map for the trails in the Madawaska area:



    I scanned a section of the map, geo-calibrated it in Google Earth and then saved it as a KMZ file. The KMZ file can be loaded in BaseCamp and on Garmin 62/78, Oregon and Montana GPS. Also, there is now an app for Android phones that has an impressive range of features including the ability to use these converted paper maps.

    Here's a screen shot in BaseCamp:



    Here it is on my HTC Sensation phone:



    Bob

    Attached Files:

  16. MikeF

    MikeF ODSC-OFTR Member

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    This makes perfect sense, thanks :) I tried Tioga first and then a small park second and both did cover a great area.

    I never thought to ask :)

    I rode a bunch of PA Forests when I was there in 2010 and I'd like to go back this season (assuming I get another bigger bike) and do it again.
  17. hardman

    hardman ODSC-OFTR Member

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    I guess in the long run since I can still load the paper maps into GE or TrackMaker, I can find out the coordinates of where I need to turn, label them and upload them into my unit. This way as I'm riding my Garmin will let me know when a turn or intersection is coming.

    I did this previously with an old Garmin I have, but actually used mapping tools with the correct scale to get the coordinates directly off the map. Never had any idea you can scan a paper map into GE to find coordinates.

    Thanks again for all your help. :)

    Hardy
  18. DualSport

    DualSport Ride Organizer

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    Not sure if I'm following you here. What do you mean by " used mapping tools with the correct scale to get the coordinates directly off the map"?

    If your problem is that this map has a UTM scale and your GPS is in Deg Min Sec, then you can set your GPS to UTM and enter coords directly. I'm not familiar with UTM - seems to be mainly used on hiking maps - but there's a good document available from Garmin on how to work with UTM and your GPS.

    If this is your issue, check this out: http://www8.garmin.com/manuals/UsingaGarminGPSwithPaperLandMaps_Manual.pdf

    Bob
  19. hardman

    hardman ODSC-OFTR Member

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    Map tools are clear plastic squares with usually a variety of various map scales. You select the scale to match the map you are using and overlay the tool directly on top of the topo section for the coordinates you want to find. It gives you fairly accurate coordinates which I have manually punched into my older Garmin.

    Map tools are actually used out in the field with topo maps (UTM only). The disadvantage is that they are time consuming to use, but it was what the US military used. After all it was the US military who developed UTM as it is much more accurate than degrees, minutes and seconds when traveling on the ground by foot. UTM was developed because its coordinates can bring you within a few feet of your destination.

    If you want to have a look at the tool I have, you will find it here at this link. http://www.maptools.com/products/CornerRules.html

    I enjoy using it, but it does take time.

    Hardy
  20. DualSport

    DualSport Ride Organizer

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    OK, I understand the UTM sysytem a little better now. There's some good tutorials on that website. Thanks.

    Bob