Jump to content

Invisible Overlays And Calibrating Maps


dhbaird

Recommended Posts

I am looking for some guidance from you map creator folk out there.

 

Here is the situation:

 

I have a collection of trail maps from my treks in place around the country that I have collected. These trail maps have been printed by various outing clubs and organizations like the Appalachian Outing Club, The Sierra Club, The Williams Outing Club, MIT and Harvard Outing Clubs etc... I also have some very custom maps given me by some mountaineering folk, like Brad Washburn of the Denaili area when we were doing some laser surveying for him during a climb in the early 70's.

 

I also have maps from some other old expeditions, adventures and treks. I used to be on the staff of Outward Bound, WILD and a couple of other East Coast based adventure training groups and have maps that are from 30+ years ago of treks in places like the Yukon, British Columbia, Colorado, The Tetons, Cascades, the Boundary Waters, Denali/Alaska/Mt Logan and a trek to some volcanos in Central and South America.

 

Many of these maps are on their last legs, deteriorating and getting ready to be re-cycled.

 

I want to begin a project of saving the information they hold. Digitizing the trails we took and transcribing some of the notes from my journals so I do not lose the information on them.

 

Has anybody done something like this? Is there any guide books on how to go about a project like this? Am I biting off something that is virtualy undoable?

 

I have read enough to conclude that probably the best way to do this is not to modify or create new base maps themselves in whatever program I am using but creating "invisible overlays"? Is that correct? How do you take a scan and turn it into an invisible layer?

 

Once you scan in a section of a map, how does one go about actually calibrating/synching the overlay to the underlying map? Do you need realtime GPS coordinates to do so?

 

Finally, with the above as my goal, is any current collection of digital Topo data lend itself to this kind of project more easily? Is there a map package I should avoid because it is too hard to do the overlays and store notes?

 

The likelyhood of my returning to all my old haunts in my approaching retirement is very slim... but I know that some of my routes and first ascents ought to be saved somehow for others who might like to follow behind.

Link to comment

You might contact someone at National geographic or Delorme, being they are in the business of creating maps someone there my know process you could use.

National geographics digital maps are made in San Francisco ( I misplaced there phone number in San Francisco), Delome maps are made back east I think in your area.

Link to comment

>>Has anybody done something like this? Is there any guide books on how to go about a project like this? Am I biting off something that is virtualy undoable?

 

Yes, read some turorials here

 

>I have read enough to conclude that probably the best way to do this is not to modify or create new base maps themselves in whatever program I am using but creating "invisible overlays"? Is that correct? How do you take a scan and turn it into an invisible layer?

 

See above. You want to creat your own maps and make them transparent.

 

>Once you scan in a section of a map, how does one go about actually calibrating/synching the overlay to the underlying map? Do you need realtime GPS coordinates to do so?

 

You need to calibrate the scanned image with something like Oziexplorer. There should be reference marks on the maps that you can use for calibration.

 

I would only look at getting the trail data into the maps. Topography, road and waterway data already exists in many products. Get one of those first to see what you might need to add,

Link to comment

If I understand your questions correctly...

 

I recommend scanning the maps and then importing them into OziExplorer and calibrating them there. You can calibrate on the basis of any known point of latitude/longitude. If these lines are not visible on the map, you can use peaks, benchmarks or road intersections. The actual coordinates can be found using any of the TerraServer based programs. TopoFusion and USAPhotoMaps are my favorites, and are much more user friendly than the TerraServer site.

 

Once you have the maps in Ozi and calibrated, you can trace the path you took, creating a track overlay. This track can then be easily transferred to other programs using various utilities or a GPS. Or you could view/print them in Ozi on a clean USGS quad. These are typically available free in electronic format (Digital Raster Graphics aka DRGs).

 

Full info on map calibration, DRGs and all the programs I mentioned can be found in my book.

 

Does this help? Sounds like a great winter project.

 

Rich Owings

http://www.MakeYourOwnMaps.com/

http://gpstracklog.typepad.com/

 

"We were desert mystics, my friends and I, poring over our maps as

others do their holy books." - Edward Abbey

Link to comment

My response focused on paper maps, not maps to go on your GPSr. If all you want is to display the track you took, it's easy to transfer these tracks to your GPS and have them show up on any map being displayed there.

 

Rich Owings

www.MakeYourOwnMaps.com

www.GPStracklog.com

 

"We were desert mystics, my friends and I, poring over our maps as others do their holy books." - Edward Abbey

Link to comment

Very Possible and fairly simple...you might need to purchase one software product like Oxiexplorer, in a nutshell...

 

Find a local source who does flatbed scanning to the size of your maps. If the maps are too big you can scan just the section with the "trail" you are interested in, making sure you have at leat three intersecting grid marks with a known Lt \Lon. 300 DPI resolution should be sufficient.

 

Once the map is scanned you have a digitized map image which is not georeferenced. Using Oziexplorer, you can import the digital map, find and mark the three calibration points entering the lat lon at the intersections, and Ozi will calibrate the map. From there, again in Oxi (or other software), you can manually click along the trail to create any number of track points you want. Then you save the track and you have a permanent record of the trail. Ozi tracks are PLT files but any one of a number of free software products can convert the track to other formats if necessary. I'm using the demo version, it's even possible the full version can do this conversion..you have to check.

 

From here you can use any map program like delorme or national geo and import, display and print your tracks (trails) on std USGS DRG or other map of your choice.

 

You could use the free drg map sources on the web, but then you get into a problem with trying to organize and manage the various map names and quads.....much simpler to decide on a good mapping program that would cover all the areas you are interested in, buy it, and use that as the source on which you lay the trails you have created. Odds are the original maps you were using were in fact USGS DRG 1:24K maps. National Geo State topo series would be the same, with some minor trail and update info added.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...