Hi All:
We have some questions (or possible suggestions) about the NetCDF subset
service.
1. Following the CF conventions, we have lat, lon, and time variables with
attributes as follows:
double time(time) ;
time:long_name = "reference time" ;
time:units = "days since 1998-01-01 " ;
time:bounds = "time_bnds" ;
time:_CoordinateAxisType = "Time" ;
float lat(lat) ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
lat:bounds = "lat_bnds" ;
lat:_CoordinateAxisType = "Lat" ;
lat:standard_name = "latitude" ;
float lon(lon) ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
lon:bounds = "lon_bnds" ;
lon:_CoordinateAxisType = "Lon" ;
lon:standard_name = "longitude" ;
Many CF complaint software use the "bounds" information in displaying the data.
When the data are subsetted using the subset service, the attributes are
carried along, but the variables themselves are not. This then causes display
programs to throw errors. I would suggest that like the coordinate system
itself, if the bounds exist they should be subsetted and brought along with the
file.
2. We have variables with the following in the original netcdf file:
float SSTTrimMean(time, lat, lon) ;
SSTTrimMean:long_name = "Trimmed 1-degree SST Monthly Mean" ;
SSTTrimMean:units = "degC" ;
SSTTrimMean:_FillValue = -9999.f ;
When the data are subsetted the returned netcdf file has the same attributes
but for the missing value now has "NaNf", which again causes a lot of heartburn
for some display programs.
Thanks,
-Roy
**********************
"The contents of this message do not reflect any position of the U.S.
Government or NOAA."
**********************
Roy Mendelssohn
Supervisory Operations Research Analyst
NOAA/NMFS
Environmental Research Division
Southwest Fisheries Science Center
1352 Lighthouse Avenue
Pacific Grove, CA 93950-2097
e-mail: Roy.Mendelssohn@xxxxxxxx (Note new e-mail address)
voice: (831)-648-9029
fax: (831)-648-8440
www: http://www.pfeg.noaa.gov/
"Old age and treachery will overcome youth and skill."
"From those who have been given much, much will be expected"
"the arc of the moral universe is long, but it bends toward justice" -MLK Jr.
