[aprssig] Re: [Xastir-dev] Re: Getting Tiger2000 data?

[Curt Mills, WE7U]

On Thu, 29 Aug 2002, Ken Koster wrote:

> the ALL_COUNTIES could
> be soft links to save space.

Nope.  You'd archive all of the separate counties into a new archive
by layer, so that you would only have to download that one file to
get, say, roads for the entire state.

You'd need double the storage in order to use this technique.  You
could alternately use one of the FTP servers that archives
on-the-spot, but because of the size of the data you might just want
to archive it once and then have the files available instead.
Again, double the storage space this way.


> Yup, just which of these do we want, and if we don't put them them on our
> site, how do we give our users the ability to add their own catagories?

I'd have pointers off to where to get the rest (README or INDEX.HTML
file), in case the user wanted more.  I'd just snag the ones that
make sense for APRS and forget the rest.


> Another question, xastir specific this time, if we modify the xastir map
> chooser to allow the selection of tigermaps by layer, do we want it to
> continue to do this alphabetically or should it understand something of
> the directory structure?  And if so, how?  hard-coded? A config file?

I vote for understanding the dir structure.  Of course that brings
up more questions.  Actually, instead of that, if we just assign
each map to a layer (perhaps named _and_ numbered, like layer2 =
lakes), then we can turn on and off individual layers at will.


> Or should we have a structure for the archive, but then just use that to
> populate a GIS aware database that xastir uses?

The database would work well for vectors, but probably not so well
for rasters.  Not sure on this one.


> And how  do we want the tigermaps to integrate with other maps.  Tigermaps
> are US only and while we could add shapefile maps for other countries we
> don't have them right now.  I want my xastir to display Tigermaps(shapefiles)
> where available and other maps where they aren't.

Well, if we get the layering set up right (8 to 256 separate
layers?) then we can assign each map to a layer within Xastir.
After that, turn on automaps and Xastir will combine the maps
together.  The tricky bits are the raster images, as they will
overwrite anything written to a layer below them.  Might want to
assign all of them to layer 1, with layer 0 being the background
color.  All vectors would get written to layer 2 or above.

Xastir will overlay any type of map on top of any other type of map,
so mixing and matching lots of maps is not a problem.  :-)

Curt Mills, WE7U                         hacker.NO_*SPAM at tc.fluke.com
Senior Methods Engineer/SysAdmin
"Lotto:    A tax on people who are bad at math." -- unknown
"Windows:  Microsoft's tax on computer illiterates." -- WE7U