Map Overlay Software

[Hardscrabble]

Hope someone can offer some suggestions...

I am searching for a map overlay application (similar in performance to google earth's overlay). I need it to be simple (like google earth's). I want to be able to overlay any pair of maps that I choose. So, I might take a tax plat map and overlay it on an old or current topo, google earth, google maps, or satellite image.

I like the simplicity of the google earth overlay. Problem is, it only works for google earth. If I want to take a historical map and overlay it on a current USGS topo or my Delorme topo, it does me no good. Has anyone downloaded something like the above?

Thanks.

[artyfacts]

One technique you could use if all is lost. Make a ruler using there scale on the map (I use the same transparency film in the next step and include your own half and quarter mile marks). Find two key points (if available) on the map in question and take a measurement. Take a piece of transparency film available at your office supply stores and transpose or trace the map area that you want on the film with a small tipped sharpie. Using Google Earth acquire the same area in question (the one on the map). Using the ruler icon in GE measure the same points you chose on your map and get the distance by zooming in or out as close as possible. Also note North on your overlay. Now place the overlay right up against your monitor screen and adjust your points so they match up. This works most of the time but remember some sections of roads can be as much as a mile off, try using key features that are harder to change, lakes, mountains, key intersections, historical points of interest. Arty

[Hardscrabble]

Arty... thank you. I will give it a shot. Should be software out there though.

[artyfacts]

I totally agree, I have the PN40. I use this technique often with great success. You can change the GE to match the DeLormes longitude and latitude. You can check this by turning on your GPS go to a easy to see point on both your hand held and Google Earth (GE) and match the lat and long numbers. This helps me downloading my waypoints that I find on Earth and gets me on the spot. Arty

[Hardscrabble]

arty...

I have used the overlay feature on Google Earth several times when using old historical topos. Of course, if you want to overlay your 1900 USGS topo over a current topo, or if you have a tax plat map you want to overlay over a modern topo you're out of luck with GE. GE only overlays maps onto GE satellite imagery.

On the other hand, I have used the above technique to locate buildings long gone. In a few cases the foundations (or outlines of foundations), were still visible on aerial photographs. Sometimes, google earth imagery also shows the foundations, etc. Oh, well... maybe something will come up. Thanks again.

[artyfacts]

Your very welcome. Another great tool that can help find foundations etc. in Earth is the time tool, different scans by Earth through the years. By using this tool you can go to a time where there is no foliage on the trees, opening up house areas and trails that are just not visible otherwise. Also using the same function and going back to the black and white (early 90s) scans can help unlock trails that are almost invisible. This has just unlocked a puzzle looking for a lost tavern. Earth cannot always be believed when dealing with roads or trails long forgotten and then mislabeled with another name at a later time. Have fun mapping. Arty

[nforest]

you may also want to spend some time getting good at photoshop, as it will do everything that you want to do but will take time to learn.

Basically you can save your maps as layers and change the transparency and adjust sizes, its not that hard, it just takes the effort to learn.

If you don't want to pay for photoshop, look up "GIMP photo program"

its an open source program similar to Photoshop.

[Hardscrabble]

nforest...

Thanks. I am pretty much sold on the utility of overlays. I'll try the GIMP version.