Can WMS be used to get a local copy of raster data?

Question

I have tried reading up on WMS on wiki and other sources but haven't managed to get my head around a couple of points.

1) Using WMS is it possible to get a local copy of the raster data (say a tiff image tile). The reason, I ask is, I need to use his raster data in a secondary process that needs a local copy of the file.

2) I am primarily interested in allowing users the option of downloading orthoimagery and elevation from the USGS repository. I've tried using the Seamless viewer but I am thinking more along the lines of user specifying a coordinate (or four corner coords) and getting the orthoimage and elevation data corresponding to that. I thought WMS (Geoserver being my first option) is the way to go for this, but not certain. So wanted to get your advice.

Thanks in advance.

Sincerely, ST.

Answer 1

If you want to provide more than a picture of the data then you probably want to consider using WCS (http://www.opengeospatial.org/standards/wcs) which allows the actual imagery to be downloaded. It is the raster equivalent of a WFS service for vector data.

Answer 2

For 1) GDAL allows you to grab a WMS and generate a tiff out of it http://www.gdal.org/frmt_wms.html

For 2), I am not sure I understand. Do you want to create a tool to extract data from seamless? If so, you may want to check out the answer by Matt (it was not the "chosen one"). He had a very clever way of extracting data from seamless.