Tilesets metadata

[LDWhite68]

Is there any chance that we could ever get access to basic metadata from the tilesets? For example, I'd like to be able to click on a point and find what date the aerial imagery was taken. Also for the official date on topo maps. That way I can make more intelligent choices about which tilesets to choose. I could also compare the Terraserver topos to USGS to see if there is a more recent map that I might want to go to the extra trouble to get from USGS (since Terraserver is getting kind of old and seems to have no hope for updates). I'm especially interested in how often the data for the public lands tileset are updated. I have seen minor differences between it versus the shapefiles and raster images available from the individual agencies, but can't tell which is the most current.

[ScottMorris]

There is some chance, yes.  Esp. for terraserver it should be possible.  Some of the other map types might be a little more difficult.  The Color aerial tileset, for example, varies and I do not know how to access that data in a programmatic way.

I am not sure about the land use layer, either.  I can dig out the link if you want to take a look.  I think somewhere on the site it lists the age of the data.

[LDWhite68]

I'd be happy to check out the land use link. But I'm not very optimistic. None of the agency websites I've downloaded from does a good job answering the question either, so I suspect that the only way to get a real answer may be to inquire directly to whoever the website caretaker is (if they can be found). Officially the answer is liable to be that updates are put in as soon as they are received from field offices. But the problem is to figure out how often they are actually provided by the agency field offices. Hopefully federal agencies send in current files at least once a year for accounting purposes, but it would be nice to know if they actually have a schedule or just send in whenever they feel like it.

[ScottMorris]

Here is a link to some info on the 'federal lands' layer:

http://www.geocommunicator.gov/GeoComm/fedland/home/fedland_about.shtm

I didn't see anything obvious about updates, only this paragraph:

The data represents the "best available" seamless source of the federal surface management agency boundaries. The most current data sets are acquired from the state or regional offices of the BLM, USFS, NPS, and other federal agencies. The data are processed into the NILS system to form a national seamless dataset. Data for the Eastern U.S. comes from the U.S. Geological Survey's National Atlas. Much of the BLM data has been snapped to the Public Land Survey System (township, range, and section) making it more accurate than previous versions of the data layers. Data is being maintain through the NILS system

Please let us know if you discover anything.