I'm currently working on developing a Google Maps API implementation that overlays topographic data from USGS Terra Server. I think I have it pretty much under hand except that I can't figure out how to determine the name of the quad, name, & scale for the current tile being served from Terra Server. If you check out this site and zoom into the map that information is being displayed so it must be possible:
http://www.trails.com/topomap.aspx?trailid=fgu003-087
Here are links to some articles which explains more how the images are named by Terra Server:
STANDARDIZED DATA SET NAMES FOR DRG PRODUCTS
I'm hoping that some geoloc expert out there has already done this and can point me in the right direction. I'd appreciate if you could give me any clues how I might determine this information from the current map view when overlaying the USGS topo data over Google Maps to produce a user experience much like that of the example map about.
Thanks in advance for your help!