On Thu, 20 Aug 2009, Robb Kambic wrote:
On Thu, 20 Aug 2009, Tor Christian Bekkvik wrote:
Hi,
I am using NetCDF to read GRIB/GRIB2 files. Almost everything works fine,
but
some GRIB parameters seems to be unavailable via the NetCDF API. I this
case,
I could not find
"RESOLUTION AND COMPONENT FLAGS (GDS OCTET 17)" from the GRIB file.
, at least not in the NetCDF attributes..
(Details: This GDS parameter from the GRIB file tells how to interpret
direction from combined U- and V- components. (In my case, current vectors
from
weather data)
Text from GRIB standards documentation:
TABLE 7 - RESOLUTION AND COMPONENT FLAGS (GDS OCTET 17):
Bit 5:
0 u- and v-components of vector quantities resolved relative
to easterly and northerly directions
1 u and v components of vector quantities resolved relative
to the defined grid in the direction of increasing x and y
(or i and j) coordinates respectively
)
- How could we get this GRIB parameter ?
Tor,
The information is available in the CDM stack, ie
GridIndex index;
List<GridDefRecord> hcsList = index.getHorizCoordSys();
for (GridDefRecord gds : hcsList) {
String windflag = gds.getParam(GridDefRecord.WIND_FLAG)
}
In my first response it was a mistake to move the discussion from the
netCDF-Java library to the lower level GRIB library without an
explanation. The purpose was to show you the code snipet of how
the value was obtained. Hopefully I didn't confuse you.
Robb...
Thanks,
Tor Chr Bekkvik
===============================================================================
Robb Kambic Unidata Program Center
Software Engineer III Univ. Corp for Atmospheric
Research
rkambic@xxxxxxxxxxxxxxxx WWW: http://www.unidata.ucar.edu/
===============================================================================
===============================================================================
Robb Kambic Unidata Program Center
Software Engineer III Univ. Corp for Atmospheric Research
rkambic@xxxxxxxxxxxxxxxx WWW: http://www.unidata.ucar.edu/
===============================================================================
