USGS National Map WMSAs explained in the previous posting in August, the new USGS National Map WMS hosts the scanned topo maps 1:24k. It can been seen as an alternative to MS Research Maps WMS.
http://raster.nationalmap.gov/arcgis/services/DRG/TNM_Digital_Raster_Graphics/MapServer/WMSServer WMS only!Unfortunately, using default methods of access, the USGS WMS only works for UTM zones 17 and up (East Coast). This can be blamed to an erroneous list of coordinate systems supported in the capabilities metadata, it's not a problem of the service itself. However, this error has not yet been corrected.
In TransDEM 2.2. I have added an override parameter. It allows you to bypass restrictions on coordinate systems. TransDEM will send any coordinate system to the server that has been selected in the WMS client, ignoring the server list. Internally, it's a bit more complicated because sometimes there are several codes or code families for a particular system. TransDEM must find a suitable code, a code it expects to be understood by the server, taking into account the (faulty) list of codes the server has provided.
This new parameter can be found in the extra settings for a WMS server. It must be enabled for the USGS WMS to access zones 10 to 16. Set the coordinate system to UTM/WGS84. The server will also reply to UTM/NAD27, but this involves additional transformation overhead in TransDEM.
You can also install the latest WMS sample configuration from my website which already includes this setup.