Hi All,
I have netcdf files that are not seen as grided by either netcdf tools ui 4.2
or my thredds 4.2 server
(http://odin.meteo.mcgill.ca:8080/thredds/catalog/testAll/catalog.html). The
data file
http://odin.meteo.mcgill.ca:8080/thredds/catalog/testAll/catalog.html?dataset=testDatasetScan/MRCC.4.2.0_amno_adj_alsi_ps_196012_r%28cf-1-4%29.nc
is representative of many terabytes of netcdf files that we are to make
available to public BUT do not fully comply to geogrid specifications
CF-1.0/COARDS (I think our files are close to be complying but something is
missing in our polar stereographic netcdf headers).
For modifying netcdf variables, I am planning on using NcML (as shown
http://www.unidata.ucar.edu/projects/THREDDS/tech/tds4.2/tutorial/NcML.htm) BUT
I don't exactly know what parameters are missing in order to connect the
polar_stereographic netcdf header information to our x and y axis.
Here attached, I have included the 2 differents types of netcdf header we use,
a netcdf dump of lat lon UTM data (which works fine with all enabled thredds
services) and a netcdf dump for polar stereographic data (which is not
perceived as gridded data just yet, see file
2010aug16_polar-stereo-netcdf_ccrm-sample.txt).
Must grid_mapping_name = polar_stereographic be specified somewhere within our
header? Do we properly link the polar_stereographic structure to the x and y
axis (xc,yc structures)?
Regards,
Stephane
--------------------------------------------------------------------
Stephane Poirier, M.Sc. Optical Physics
Remote Sensing Application Software Developer
Geography Department, Burnside Hall
McGill University, Montreal, QC, Canada
http://geog.mcgill.ca
Stephane.Poirier2@xxxxxxxxx
Cell. (514) 994-3532
Fax: (514) 509-8833
--------------------------------------------------------------------
Stephane Poirier, M.Sc. Optical Physics
Remote Sensing Application Software Developer
3532 rue Sainte-Famille, Apt. 4
Montreal, QC, H2X 2L1, Canada
http://www.oifii.org
stephane.poirier@xxxxxxxxx
Tel.: (514) 509-8833
Fax: (514) 509-8833
--------------------------------------------------------------------
>> nc_dump('http://odin.meteo.mcgill.ca:8080/thredds/dodsC/testAll/MRCC.4.2.0_amno_adj_alsi_ps_196012_r(cf-1-4).nc');
URL
http://odin.meteo.mcgill.ca:8080/thredds/dodsC/testAll/MRCC.4.2.0_amno_adj_alsi_ps_196012_r(cf-1-4).nc
{
dimensions:
yc = 174 ;
xc = 182 ;
time = UNLIMITED ; (124 currently)
variables:
// Preference 'PRESERVE_FVD': false,
// dimensions consistent with ncBrowse, not with native MATLAB netcdf
package.
single yc(yc), shape = [174]
yc:units = "m"
yc:long_name = "y-coordinate of polar-stereographic projection"
yc:standard_name = "projection_y_coordinate"
yc:axis = "y"
yc:coordinate_defines = "point"
yc:actual_range = 22500.000000 7807500.000000 f
single xc(xc), shape = [182]
xc:units = "m"
xc:long_name = "x-coordinate of polar-stereographic projection"
xc:standard_name = "projection_x_coordinate"
xc:axis = "x"
xc:coordinate_defines = "point"
xc:actual_range = 22500.000000 8167500.000000 f
double time(time), shape = [124]
time:long_name = "time"
time:standard_name = "time"
time:axis = "T"
time:units = "hours since 1958-01-01 00:00:0.0"
time:delta_t = "0000-00-00 06:00:00"
time:coordinate_defines = "point"
time:actual_range = 25536.000000 26274.000000 f
char polar_stereographic([]), shape = [1]
polar_stereographic:straight_vertical_longitude_from_pole =
245.000000 f
polar_stereographic:standard_parallel = 60.000000 f
polar_stereographic:false_easting = -6452999.500000 f
polar_stereographic:false_northing = -256499.984375 f
polar_stereographic:hemisphere_of_standard_parallel = 1.000000 f
polar_stereographic:resolution_at_standard_parallel =
45000.000000 f
single lon(yc,xc), shape = [174 182]
lon:_CoordinateAxes = "yc xc "
lon:units = "degrees_east"
lon:long_name = "longitude"
lon:standard_name = "longitude"
lon:actual_range = 0.041580 359.956024 f
single lat(yc,xc), shape = [174 182]
lat:_CoordinateAxes = "yc xc "
lat:units = "degrees_north"
lat:long_name = "latitude"
lat:standard_name = "latitude"
lat:actual_range = 10.295872 89.905121 f
int16 alsi(time,yc,xc), shape = [124 174 182]
alsi:_CoordinateAxes = "time yc xc "
alsi:long_name = "Near IR surface albedo"
alsi:units = "1"
alsi:actual_range = 0.000000 0.720000 f
alsi:add_offset = 0.000000 f
alsi:scale_factor = 0.000022 f
alsi:coordinate = "lon lat"
alsi:grid_mapping_name = "polar-stereographic"
alsi:level_desc = "Surface"
alsi:grid_desc = "polar-stereographic"
//global attributes:
:Conventions = "CF-1.0"
:title = "Donnees MRCC"
:description = "Donnees de sorties MRCC archivees aux 6 heures"
:run = "adj MRCC 4.2.0"
:run_baseline = "19601201 to 19901231"
:atmospheric_nesting_data = "CGCM3 mc_abv aux 6 heures"
:atmospheric_nesting_technic = "large scale nudging (config
PS1)"
:prescribed_ocean_data = "CGCM3 mc_abv daily SST and sea-ice"
:ghg_scenario = "OBSERVED till 20001231 then IPCC SRES A2"
:spinup_period = "from 19580101 to 19601130 removed"
:mrcc_domain = "AMNO 201x193 polar stereo 45km grid real at
60deg.N"
:nesting_relaxation_zone = "surrounding 9 grid points removed"
:history = "22-Jul-2010 15:37:06: CF1.4 revision by SP,
2010july22.
created 13/02/2007 by Helene Cote"
:format_conversion = "cdf2ccc 1.5 using netcdf-3.6.1"
:institution = "Ouranos/Equipe Simulations Climatiques"
:reference = "http://www.ouranos.ca";
}>> nc_dump('C:\oifii-org\do-org\doa\adj_st_lat20.0_50.0_lon-90.0_-20.0_196012(smaller)
>> (1).nc');
netCDF
C:\oifii-org\do-org\doa\adj_st_lat20.0_50.0_lon-90.0_-20.0_196012(smaller)
(1).nc {
dimensions:
time = UNLIMITED ; (44 currently)
level = 1 ;
lat = 61 ;
lon = 141 ;
variables:
// Preference 'PRESERVE_FVD': false,
// dimensions consistent with ncBrowse, not with native MATLAB netcdf
package.
int16 st(time,level,lat,lon), shape = [44 1 61 141]
st:long_name = "2 meter screen temperature"
st:units = "K"
st:statistic = "6 hourly mean"
st:standard_name = "screen_temperature"
st:actual_range = 239.726929 312.565887 f
st:add_offset = 239.726929 f
st:scale_factor = 0.002223 f
st:level_desc = "2 m"
st:grid_desc = "lon/lat regional"
st:coordinates = "time level lat lon lat lon"
double time(time), shape = [44]
time:long_name = "time"
time:standard_name = "time"
time:axis = "t"
time:units = "hours since 1958-01-02 00:00:0.0"
time:delta_t = "0000-00-00 06:00:00"
time:coordinate_defines = "point"
time:actual_range = 25536.000000 26274.000000 f
time:_CoordinateAxisType = "Time"
single level(level), shape = [1]
level:units = "m"
level:long_name = "2 m"
level:axis = "z"
level:positive = "up"
level:coordinate_defines = "point"
level:actual_range = 2.000000 2.000000 f
level:_CoordinateAxisType = "Height"
level:_CoordinateZisPositive = "up"
single lat(lat), shape = [61]
lat:units = "degrees_north"
lat:long_name = "latitude"
lat:standard_name = "latitude"
lat:axis = "y"
lat:coordinate_defines = "point"
lat:actual_range = 20.000000 50.000000 f
lat:_CoordinateAxisType = "Lat"
single lon(lon), shape = [141]
lon:units = "degrees_east"
lon:long_name = "longitude"
lon:standard_name = "longitude"
lon:axis = "x"
lon:coordinate_defines = "point"
lon:actual_range = 270.000000 340.000000 f
lon:_CoordinateAxisType = "Lon"
//global attributes:
:Conventions = "CF-1.0"
:title = "Donnees MRCC"
:description = "Donnees de sorties MRCC archivees aux 6 heures"
:run = "adj MRCC 4.2.0"
:run_baseline = "19601201 to 19901231"
:atmospheric_nesting_data = "CGCM3 mc_abv aux 6 heures"
:atmospheric_nesting_technic = "large scale nudging (config
PS1)"
:prescribed_ocean_data = "CGCM3 mc_abv daily SST and sea-ice"
:ghg_scenario = "OBSERVED till 20001231 then IPCC SRES A2"
:spinup_period = "from 19580101 to 19601130 removed"
:mrcc_domain = "AMNO 201x193 polar stereo 45km grid real at
60deg.N"
:nesting_relaxation_zone = "surrounding 9 grid points removed"
:history = "created 13/02/2007 by Helene Cote"
:format_conversion = "cdf2ccc 1.5 using netcdf-3.6.1"
:institution = "Ouranos/Equipe Simulations Climatiques"
:reference = "http://www.ouranos.ca";
:History = "Translated to CF-1.0 Conventions by Netcdf-Java CDM
(NetcdfCFWriter)
Original Dataset =
/opt/apache-tomcat-6.0.16/content/thredds/public/testdata/adj_st_lat20.0_50.0_lon-90.0_-20.0_196012(smaller).nc;
Translation Date = Sat Aug 14 09:05:11 EDT 2010"
}
