google maps tool
Posted: Thu Sep 10, 2009 2:23 am
The ability to overlay multiple map types with varying transparency has existed with Google Maps for some time now, but the only applications I've seen have been to drop the opacity of the background layer to make a poly shape - like a gps track - stand out better.
I created a page at
http://mattj.net/overlaymap.html
that allows you to mix and match two different layers with variable opacity. As you scroll, zoom or change layers, the URL is constantly updated, so at any point you can bookmark the URL, cut and paste it into an email, etc. It's a fun toy to play with but viewing satellite and topo imagery on top of each other or relief-shaded satellite images also has practical applications. Check out the following examples:
bay area, satellite w/ shaded relief:
http://mattj.net/overlaymap.html#center=37.82497195707114,-122.288818359375&zoom=9&base=Ter&overlay=Sat&opacity=0.5
regional park trails w/ shaded relief:
http://mattj.net/overlaymap.html#center=37.82314142578527,-122.17650890350342&zoom=15&base=Ter&overlay=OpenStreetMap&opacity=0.5
rainier, shaded relief satellite:
http://mattj.net/overlaymap.html#center=46.864885961378874,-121.77177429199219&zoom=11&base=Ter&overlay=Sat&opacity=0.5
yosemite valley topo w/ satellite
http://mattj.net/overlaymap.html#center=37.74173863896063,-119.57588195800781&zoom=14&base=MyTopo&overlay=Sat&opacity=0.5
Even though the URL updates, it's a standalone webpage with no server-side component, so you can save the HTML file locally and run it that way as well.
I'm sure this has been done before but I couldn't find any examples of it. Enjoy!
I created a page at
http://mattj.net/overlaymap.html
that allows you to mix and match two different layers with variable opacity. As you scroll, zoom or change layers, the URL is constantly updated, so at any point you can bookmark the URL, cut and paste it into an email, etc. It's a fun toy to play with but viewing satellite and topo imagery on top of each other or relief-shaded satellite images also has practical applications. Check out the following examples:
bay area, satellite w/ shaded relief:
http://mattj.net/overlaymap.html#center=37.82497195707114,-122.288818359375&zoom=9&base=Ter&overlay=Sat&opacity=0.5
regional park trails w/ shaded relief:
http://mattj.net/overlaymap.html#center=37.82314142578527,-122.17650890350342&zoom=15&base=Ter&overlay=OpenStreetMap&opacity=0.5
rainier, shaded relief satellite:
http://mattj.net/overlaymap.html#center=46.864885961378874,-121.77177429199219&zoom=11&base=Ter&overlay=Sat&opacity=0.5
yosemite valley topo w/ satellite
http://mattj.net/overlaymap.html#center=37.74173863896063,-119.57588195800781&zoom=14&base=MyTopo&overlay=Sat&opacity=0.5
Even though the URL updates, it's a standalone webpage with no server-side component, so you can save the HTML file locally and run it that way as well.
I'm sure this has been done before but I couldn't find any examples of it. Enjoy!