Other databases

[dahemac]

This must be covered elsewhere, but I cannot find it.
A list of available datasets and a list of sources of additional datasets would be much appreciated. Detailed shp files outside North America and the USA would be great.

[daan]

Here’s a list of datasets that ship with Geocart:
http://www.mapthematics.com/FAQs.php#databases

We are always on the lookout for good data that does not require our users to enter into a license with the supplier. (We think it’s best if we just stay out of the way in the case of licensed data.)

Happy mapping!
— daan

[dahemac]

Ah, so how would I find the licensed data?

[daan]

We don’t keep lists of third-party data, though now would be a good time to start. Anyone, feel free to chime in if you know of high quality Shapefile data available for licensing, particularly at medium scales.

— daan

[dahemac]

Every bit of data makes Geocart more useful.

[PJPugliese]

How can I use Aster Land Data files in Geocart. What other high resolution terrain data bases are available to use with Geocart?

[daan]

Hi, Paul. I would love to give you an easy answer, but I’m not coming up with one. I examined ASTER GeoTIFF files. The images are rotated with respect to the projected coordinate system they claim to be in (UTM). The claimed east/west/north/south boundaries do not coincide with the image boundaries, so there are translations and rotations required in order to interpret each image. Geocart can do those things, but it does not read the GeoTIFF metadata. That means the human (you) would have to figure out how the image relates to the coordinate system.

The relevant GeoTIFF tags are jumbled up in an immense amount of metadata concerning all aspects of the imagery, including things like camera angles and sensor configurations.

• •MAPORIENTATIONANGLE—This is how much the projection must get rotated with respect to the image.
  •UPPERLEFT, UPPERRIGHT, LOWERLEFT, LOWERRIGHT—These are the absolute coordinates of the parallelogram corners of the satellite imagery, excluding the black padding around it that forms the remainder of the TIFF image rectangle.
  •WESTBOUNDINGCOORDINATE, NORTHBOUNDINGCOORDINATE, EASTBOUNDINGCOORDINATE, SOUTHBOUNDINGCOORDINATE—These appear to specify the smallest north/south/east/west bounding rectangle that can contain the satellite imagery, so it is a reasonable boundary specification for georeferencing withing Geocart.
  •UTMZONECODE—There seem to be several of these with digits appended to the UTMZONECODE keyword. The east/west zone designation coincides with Geocart’s, but the northsouth is some other convention.

I was not able to make complete sense of what I see; even with those parameters above, the fit was poor. There is some other transformation I have not yet found. Perhaps the TIFF image is not 1:1 aspect ratio for pixels.

We would like Geocart to read GeoTIFF and will probably add some capability for it, but it’s also true that the quality of GeoTIFF files varies drastically, including how writers and readers interpret them. The can of worms it opens up is immense, and so far Geocart clients have not been clamoring for it.

Thanks, and good luck.
— daan