Hi Ivan –
THREDDS uses a NcWMS (http://www.resc.rdg.ac.uk/trac/ncWMS/) plugin as the WMS
server. Code has been written to generate the ‘barb’ plots you are speaking
about in NcWMS, but it has not found its way back into the NcWMS codebase and
from there into a THREDDS release.
If you are comfortable installing NcWMS outside of THREDDS, you can use this
WAR file (rename to ncwms.war before deploying) to get additional vector and
You can also wait out the integration back into THREDDS if you don’t have an
immediate need for the styles. I believe the new styles will be available in
the first release of TDS 4.3.
If you have any questions please let me know,
Side note: There have been reports that the new vector and barb styles take
almost twice as long to generate than the original styles.
[mailto:thredds-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Ivan Price
Sent: Wednesday, September 26, 2012 5:13 AM
Subject: [thredds] thredds WMS vector wind layer alone without velocity image
We are using the excellent wind direction auto-variable feature of THREDDS,
whereby after defining our ‘eastward_wind’ and ‘northward_wind’ we are able to
get the direction and strength map via the layer ‘wind’.
my question: we have seen we can ask for the map in various styles, affecting
the colour palette and scale of the underlying wind velocity image. we would
like to know if it is possible to remove altogether the underlying image,
leaving only the wind direction arrows. I have thought about defining a palette
with only a single transparent colour, but I’m not sure if that is possible as
the palettes don’t seem to support alpha values.
And perhaps in the same question if anyone has ever investigated having the
arrows to reflect the wind velocity in the typical ‘quiver’ type way.. this has
probably been discussed before but I can’t find any reference.
thanks and regards