DoctorWhy
Full Member
Others have probably had this same desire and have already figured out how to load images of old and historic maps onto a hand-held GPS. But I just figured out how, couple of days ago.
I have several hi-res digital copies of local maps (found on-line at sources like the National Archives, USGS, and Smithsonian websites). These maps go back to the mid-1700's, late 1800's, and early/mid-1900's.
All of us probably find this kind of map valuable for locating old sites for metal detector hunting. Taking a paper copy of these maps can be helpful in the field, but in the 'deep woods' it is difficult to precisely navigate to specific sites -- just using those maps and compass -- or even a GPS with 'modern' map imagery.
I stumbled onto a website: www.maptiler.com
They have free and for-pay software that you can use to take a digital image of any map and convert it into a "Custom Map" that can be easily downloaded to a "Garmin" GPS. One of their processes involves graphically, spatially 'registering' features on your digital map to a modern map image (or GoogleEarth image). Basically, I matched 32 cross-road intersections that appear on both the modern and the historic map (in my case, a highly accurate and detailed USCGS 1881 map of Penobscot Bay). The software then uses these common 'tie points' to resolve the historic map to GPS positions. The more 'tie points' you create, the more spatially accurate the map. MapTiler's free version of the software is limited to converting a 10,000 x 10,000 pixel digital map to a 'Custom Map' for the Garmin hand-held (e.g., Garmin Montana). That pixel limit allowed me to create a GPS overlay that had reasonable resolution for the 9mi x 6mi island on which I live. After following the website's on-line instructions and downloading the newly created map to my Garmin Montana, I took it on a test drive around the island. The GPS route mapped extremely well compared with the driven route.
The greater the spatial accuracy of your historic map and the amount of effort you put into creating numerous 'tie points', the greater the GPS position/graphical position accuracy will be.
Now I can't wait to get out in the woods and see how closely I can locate those long-forgotten woods roads, stone walls and cellar holes.
Happy Holidays and Happy Hunting,
--Bert
I have several hi-res digital copies of local maps (found on-line at sources like the National Archives, USGS, and Smithsonian websites). These maps go back to the mid-1700's, late 1800's, and early/mid-1900's.
All of us probably find this kind of map valuable for locating old sites for metal detector hunting. Taking a paper copy of these maps can be helpful in the field, but in the 'deep woods' it is difficult to precisely navigate to specific sites -- just using those maps and compass -- or even a GPS with 'modern' map imagery.
I stumbled onto a website: www.maptiler.com
They have free and for-pay software that you can use to take a digital image of any map and convert it into a "Custom Map" that can be easily downloaded to a "Garmin" GPS. One of their processes involves graphically, spatially 'registering' features on your digital map to a modern map image (or GoogleEarth image). Basically, I matched 32 cross-road intersections that appear on both the modern and the historic map (in my case, a highly accurate and detailed USCGS 1881 map of Penobscot Bay). The software then uses these common 'tie points' to resolve the historic map to GPS positions. The more 'tie points' you create, the more spatially accurate the map. MapTiler's free version of the software is limited to converting a 10,000 x 10,000 pixel digital map to a 'Custom Map' for the Garmin hand-held (e.g., Garmin Montana). That pixel limit allowed me to create a GPS overlay that had reasonable resolution for the 9mi x 6mi island on which I live. After following the website's on-line instructions and downloading the newly created map to my Garmin Montana, I took it on a test drive around the island. The GPS route mapped extremely well compared with the driven route.
The greater the spatial accuracy of your historic map and the amount of effort you put into creating numerous 'tie points', the greater the GPS position/graphical position accuracy will be.
Now I can't wait to get out in the woods and see how closely I can locate those long-forgotten woods roads, stone walls and cellar holes.
Happy Holidays and Happy Hunting,
--Bert
