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Re: 20040226:valtime_offset problems gribtonc
- Subject: Re: 20040226:valtime_offset problems gribtonc
- Date: Mon, 1 Mar 2004 10:03:45 -0700 (MST)
Lori,
I received the grib file and created a cdl file for your isabel data.
The cdl from gribtocdl had to be modified a litte because it had
valtime offsets of 0 and 6 because the PRECIP var is actually a time
range and gribtocdl doesn't handle that well. ie
From gribdump:
Time Range Indicator : Accumulation from P1 to P2
Time 1 (P1) : 0
Time 2 (P2) : 6
other vars were similar too:
Time Range Indicator : Reference Time + P1
Time 1 (P1) : 6
When gribtonc ran on the data, it only created one record for the 6 hr data.
The cdl is a attached.
Robb...
On Thu, 26 Feb 2004, Robb Kambic wrote:
> On Thu, 26 Feb 2004, Unidata Support wrote:
>
> >
> > ------- Forwarded Message
> >
> > >To: address@hidden
> > >From: Lori Thompson <address@hidden>
> > >Subject: valtime_offset problems
> > >Organization: UCAR/Unidata
> > >Keywords: 200402261855.i1QItjrV024503
> >
> > We recently upgraded to the decoders version 3.0.2. I am converting a
> > dataset from grib to NetCDF. During the conversion, each snapshot file was
> > concatenated using nccatm to produce a time series file. I seem to be
> > running into problems with this newer version where additional points are
> > added to the record dimension during gribtonc, creating additional
> > 9actually doubling) blank frames in the time series. I have made several
> > attempts to manipulate the CDL file so that the record dimension will only
> > have 1 value per file but these efforts failed. Is there a new feature
> > with the upgrade that is causing this, or am I doing something wrong?
>
>
> Lori,
>
> I am not quite sure that what your question is?
>
> The valtime_offsets are extracted from the data files. The
> offsets must be in the raw grib data you used to make the cdl. You could
> use use the gribdump utility to check your grib input file. ie
>
> % gribdump <rawgrib> | less
> ...
> Time Range Indicator : Reference Time + Long P1
> Time 1 (P1) : 0
> Time 2 (P2) : 12
> ...
>
> This would result in a valtime_offset of 12. You could edit the cdl file
> in the data section. Removing some of the values for the
> valtime_offset, only used the offsets in the data that you are decoding.
>
> I don't know what the result would be if the variable valtime_offset was
> removed from the data section. You would get some errors but not fatal
> errors.
>
>
> If none of the above ideas work, you might want to use the old version of
> the decoder and modify the gribtocdl file section to look like lines
> 1882-1937 in the latest gribtocdl. I think that the actual changes might
> be only a couple lines in that section. A simple recompile might solve
> your problem.
>
> Let me know your findings. If you are still having problems, send me your
> cdl an a sample grib file.
>
> Robb....
>
>
> >
> > Thanks,
> > Lori
> >
> > --
> > ----------------------------------------------------
> > Lori A. Thompson
> > Applications Programmer/RS Information Systems, Inc.
> > Geophysical Fluid Dynamics Laboratory/NOAA
> > Princeton University Forrestal Campus/Route 1
> > PO Box 308
> > Princeton, NJ 08542
> > Phone: 609-452-6563
> > Fax: 609-987-5063
> > http://www.gfdl.noaa.gov/~lat
> >
> > --
> > NOTE: All email exchanges with Unidata User Support are recorded in the
> > Unidata inquiry tracking system and then made publically available
> > through the web. If you do not want to have your interactions made
> > available in this way, you must let us know in each email you send to us.
> >
> > ------- End of Forwarded Message
> >
>
> ===============================================================================
> Robb Kambic Unidata Program Center
> Software Engineer III Univ. Corp for Atmospheric Research
> address@hidden WWW: http://www.unidata.ucar.edu/
> ===============================================================================
>
===============================================================================
Robb Kambic Unidata Program Center
Software Engineer III Univ. Corp for Atmospheric Research
address@hidden WWW: http://www.unidata.ucar.edu/
===============================================================================netcdf Replace_with_model_name{
dimensions:
record = UNLIMITED ; // (reference time, forecast time)
lat = 225 ; // latitude
lon = 225 ; // longitude
fhg = 1 ; // fixed height above ground
bls = 1 ; // depth below land surface
level = 21 ; // isobaric levels
time_len = 21 ; // string length for datetime strings
valtime_offset = 1 ; // number of offset times
nmodels = 1 ; // number of models
ngrids = 1 ; // number of grids
nav = 1 ; // for navigation
nav_len = 100 ; // max string length for navigation strings
variables:
double reftime(record) ; // reference time of the model
reftime:long_name = "reference time" ;
reftime:units = "hours since 1992-1-1" ;
double valtime(record) ; // forecast time ("valid" time)
valtime:long_name = "valid time" ;
valtime:units = "hours since 1992-1-1" ;
:record = "reftime, valtime" ; // "dimension attribute" -- means
// (reftime, valtime) uniquely
// determine record
char datetime(record, time_len) ; // derived from reftime
datetime:long_name = "reference date and time" ;
// units YYYY-MM-DD hh:mm:ssZ (ISO 8601)
double valtime_offset(valtime_offset) ; // valtime - reftime
valtime_offset:long_name = "hours from reference time" ;
valtime_offset:units = "hours" ;
char forecasttime(record, time_len) ; // derived from valtime
forecasttime:long_name = "forecast date and time" ;
// units YYYY-MM-DD hh:mm:ssZ (ISO 8601)
float fhg(fhg) ;
fhg:long_name = "fixed height above ground" ;
fhg:units = "meters" ;
float bls(bls) ;
bls:long_name = "depth below land surface" ;
bls:units = "cm" ;
float level(level) ;
level:long_name = "isobaric level" ;
level:units = "hectopascals" ;
// The following lat and lon coordinate variables are redundant,
// since the navigation variables provide the necessary information.
// The extra information is included here for human readability.
float lat(lat) ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
float lon(lon) ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
long model_id(nmodels) ;
model_id:long_name = "generating process ID number" ;
// navigation variables all use nav dimension
char nav_model(nav, nav_len) ; // navigation parameterization
nav_model:long_name = "navigation model name" ;
int grid_type_code(nav) ;
grid_type_code:long_name = "GRIB-1 GDS data representation type"
;
char grid_type(nav, nav_len) ;
grid_type:long_name = "GRIB-1 grid type" ;
char grid_name(nav, nav_len) ;
grid_name:long_name = "grid name" ;
int grid_center(nav) ;
grid_center:long_name = "GRIB-1 originating center ID" ;
int grid_number(nav, ngrids) ;
grid_number:long_name = "GRIB-1 catalogued grid numbers" ;
grid_number:_FillValue = -9999 ;
char i_dim(nav, nav_len) ;
i_dim:long_name = "longitude dimension name" ;
char j_dim(nav, nav_len) ;
j_dim:long_name = "latitude dimension name" ;
int Ni(nav) ;
Ni:long_name = "number of points along a latitude circle" ;
int Nj(nav) ;
Nj:long_name = "number of points along a longitude circle" ;
float La1(nav) ;
La1:long_name = "latitude of first grid point" ;
La1:units = "degrees_north" ;
float Lo1(nav) ;
Lo1:long_name = "longitude of first grid point" ;
Lo1:units = "degrees_east" ;
float La2(nav) ;
La2:long_name = "latitude of last grid point" ;
La2:units = "degrees_north" ;
float Lo2(nav) ;
Lo2:long_name = "longitude of last grid point" ;
Lo2:units = "degrees_east" ;
float Di(nav) ;
Di:long_name = "longitudinal direction increment" ;
Di:units = "degrees" ;
float Dj(nav) ;
Dj:long_name = "latitudinal direction increment" ;
Dj:units = "degrees" ;
byte ResCompFlag(nav) ;
ResCompFlag:long_name = "resolution and component flags" ;
// end of navigation variables
float P_msl(record,lat,lon) ;
P_msl:long_name = "Pressure reduced to MSL at mean sea level" ;
P_msl:GRIB_parameter_number = 2 ;
P_msl:GRIB_level_flag = 102 ;
P_msl:units = "Pa" ;
P_msl:_FillValue = -9999.f ;
P_msl:navigation = "nav" ;
float PRECIP(record,lat,lon) ;
PRECIP:long_name = "Total precipitation at surface of the earth"
;
PRECIP:GRIB_parameter_number = 61 ;
PRECIP:GRIB_level_flag = 1 ;
PRECIP:units = "kg/m2" ;
PRECIP:_FillValue = -9999.f ;
PRECIP:navigation = "nav" ;
float u_fhg(record,fhg,lat,lon) ;
u_fhg:long_name = "u-component of wind at fixed height above
ground" ;
u_fhg:GRIB_parameter_number = 33 ;
u_fhg:GRIB_level_flag = 105 ;
u_fhg:units = "m/s" ;
u_fhg:_FillValue = -9999.f ;
u_fhg:navigation = "nav" ;
float u(record,level,lat,lon) ;
u:long_name = "u-component of wind at isobaric levels" ;
u:GRIB_parameter_number = 33 ;
u:GRIB_level_flag = 100 ;
u:units = "m/s" ;
u:_FillValue = -9999.f ;
u:navigation = "nav" ;
float v_fhg(record,fhg,lat,lon) ;
v_fhg:long_name = "v-component of wind at fixed height above
ground" ;
v_fhg:GRIB_parameter_number = 34 ;
v_fhg:GRIB_level_flag = 105 ;
v_fhg:units = "m/s" ;
v_fhg:_FillValue = -9999.f ;
v_fhg:navigation = "nav" ;
float v(record,level,lat,lon) ;
v:long_name = "v-component of wind at isobaric levels" ;
v:GRIB_parameter_number = 34 ;
v:GRIB_level_flag = 100 ;
v:units = "m/s" ;
v:_FillValue = -9999.f ;
v:navigation = "nav" ;
float T_sfc(record,lat,lon) ;
T_sfc:long_name = "Temperature at surface of the earth" ;
T_sfc:GRIB_parameter_number = 11 ;
T_sfc:GRIB_level_flag = 1 ;
T_sfc:units = "degK" ;
T_sfc:_FillValue = -9999.f ;
T_sfc:navigation = "nav" ;
float T_bls(record,bls,lat,lon) ;
T_bls:long_name = "Temperature at depth below land surface" ;
T_bls:GRIB_parameter_number = 11 ;
T_bls:GRIB_level_flag = 111 ;
T_bls:units = "degK" ;
T_bls:_FillValue = -9999.f ;
T_bls:navigation = "nav" ;
float T(record,level,lat,lon) ;
T:long_name = "Temperature at isobaric levels" ;
T:GRIB_parameter_number = 11 ;
T:GRIB_level_flag = 100 ;
T:units = "degK" ;
T:_FillValue = -9999.f ;
T:navigation = "nav" ;
float RH(record,level,lat,lon) ;
RH:long_name = "Relative humidity at isobaric levels" ;
RH:GRIB_parameter_number = 52 ;
RH:GRIB_level_flag = 100 ;
RH:units = "percent" ;
RH:_FillValue = -9999.f ;
RH:navigation = "nav" ;
float Z(record,level,lat,lon) ;
Z:long_name = "Geopotential height at isobaric levels" ;
Z:GRIB_parameter_number = 7 ;
Z:GRIB_level_flag = 100 ;
Z:units = "gp m" ;
Z:_FillValue = -9999.f ;
Z:navigation = "nav" ;
// global attributes
:history = "2004-03-01 09:43:36 - created by gribtocdl" ;
:title = "Enter model definition here" ;
:Conventions = "NUWG" ;
:GRIB_reference = "Office Note 388 GRIB" ;
:GRIB_URL = "http://www.nco.ncep.noaa.gov/pmb/docs/on388/"; ;
:version = 0.0 ;
data:
fhg = 35.0 ;
bls = 50.0 ;
level = 1000.0, 950.0, 900.0, 850.0, 800.0, 750.0, 700.0, 650.0, 600.0, 550.0,
500.0, 450.0, 400.0, 350.0, 300.0, 250.0, 200.0, 150.0, 100.0, 50.0,
10.0 ;
model_id = 70 ;
valtime_offset = 6 ;
// Navigation
nav_model = "GRIB1" ;
grid_type_code = 0 ;
grid_type = "Latitude/Longitude" ;
grid_name = " " ;
grid_center = 7 ;
grid_number = 255 ;
i_dim = "lon" ;
j_dim = "lat" ;
Ni = 225 ;
Nj = 225 ;
La1 = -14.833000 ;
Lo1 = -104.833000 ;
La2 = 59.833000 ;
Lo2 = -30.167000 ;
Di = 0.333000 ;
Dj = 0.333000 ;
ResCompFlag = 128 ;
lon =-104.83,-104.50,-104.17,-103.83,-103.50,-103.17,-102.83,-102.50,
-102.17,-101.84,-101.50,-101.17,-100.84,-100.50,-100.17,-99.84,
-99.50,-99.17,-98.84,-98.51,-98.17,-97.84,-97.51,-97.17,
-96.84,-96.51,-96.17,-95.84,-95.51,-95.18,-94.84,-94.51,
-94.18,-93.84,-93.51,-93.18,-92.84,-92.51,-92.18,-91.85,
-91.51,-91.18,-90.85,-90.51,-90.18,-89.85,-89.51,-89.18,
-88.85,-88.52,-88.18,-87.85,-87.52,-87.18,-86.85,-86.52,
-86.18,-85.85,-85.52,-85.19,-84.85,-84.52,-84.19,-83.85,
-83.52,-83.19,-82.85,-82.52,-82.19,-81.86,-81.52,-81.19,
-80.86,-80.52,-80.19,-79.86,-79.52,-79.19,-78.86,-78.53,
-78.19,-77.86,-77.53,-77.19,-76.86,-76.53,-76.19,-75.86,
-75.53,-75.20,-74.86,-74.53,-74.20,-73.86,-73.53,-73.20,
-72.86,-72.53,-72.20,-71.87,-71.53,-71.20,-70.87,-70.53,
-70.20,-69.87,-69.53,-69.20,-68.87,-68.54,-68.20,-67.87,
-67.54,-67.20,-66.87,-66.54,-66.20,-65.87,-65.54,-65.21,
-64.87,-64.54,-64.21,-63.87,-63.54,-63.21,-62.87,-62.54,
-62.21,-61.88,-61.54,-61.21,-60.88,-60.54,-60.21,-59.88,
-59.54,-59.21,-58.88,-58.55,-58.21,-57.88,-57.55,-57.21,
-56.88,-56.55,-56.21,-55.88,-55.55,-55.22,-54.88,-54.55,
-54.22,-53.88,-53.55,-53.22,-52.88,-52.55,-52.22,-51.89,
-51.55,-51.22,-50.89,-50.55,-50.22,-49.89,-49.55,-49.22,
-48.89,-48.56,-48.22,-47.89,-47.56,-47.22,-46.89,-46.56,
-46.22,-45.89,-45.56,-45.23,-44.89,-44.56,-44.23,-43.89,
-43.56,-43.23,-42.89,-42.56,-42.23,-41.90,-41.56,-41.23,
-40.90,-40.56,-40.23,-39.90,-39.56,-39.23,-38.90,-38.57,
-38.23,-37.90,-37.57,-37.23,-36.90,-36.57,-36.23,-35.90,
-35.57,-35.24,-34.90,-34.57,-34.24,-33.90,-33.57,-33.24,
-32.90,-32.57,-32.24,-31.91,-31.57,-31.24,-30.91,-30.57,
-30.24 ;
lat =-14.83,-14.50,-14.17,-13.83,-13.50,-13.17,-12.83,-12.50,
-12.17,-11.84,-11.50,-11.17,-10.84,-10.50,-10.17, -9.84,
-9.50, -9.17, -8.84, -8.51, -8.17, -7.84, -7.51, -7.17,
-6.84, -6.51, -6.17, -5.84, -5.51, -5.18, -4.84, -4.51,
-4.18, -3.84, -3.51, -3.18, -2.84, -2.51, -2.18, -1.85,
-1.51, -1.18, -0.85, -0.51, -0.18, 0.15, 0.49, 0.82,
1.15, 1.48, 1.82, 2.15, 2.48, 2.82, 3.15, 3.48,
3.82, 4.15, 4.48, 4.81, 5.15, 5.48, 5.81, 6.15,
6.48, 6.81, 7.15, 7.48, 7.81, 8.14, 8.48, 8.81,
9.14, 9.48, 9.81, 10.14, 10.48, 10.81, 11.14, 11.47,
11.81, 12.14, 12.47, 12.81, 13.14, 13.47, 13.81, 14.14,
14.47, 14.80, 15.14, 15.47, 15.80, 16.14, 16.47, 16.80,
17.14, 17.47, 17.80, 18.13, 18.47, 18.80, 19.13, 19.47,
19.80, 20.13, 20.47, 20.80, 21.13, 21.46, 21.80, 22.13,
22.46, 22.80, 23.13, 23.46, 23.80, 24.13, 24.46, 24.79,
25.13, 25.46, 25.79, 26.13, 26.46, 26.79, 27.13, 27.46,
27.79, 28.12, 28.46, 28.79, 29.12, 29.46, 29.79, 30.12,
30.46, 30.79, 31.12, 31.45, 31.79, 32.12, 32.45, 32.79,
33.12, 33.45, 33.79, 34.12, 34.45, 34.78, 35.12, 35.45,
35.78, 36.12, 36.45, 36.78, 37.12, 37.45, 37.78, 38.11,
38.45, 38.78, 39.11, 39.45, 39.78, 40.11, 40.45, 40.78,
41.11, 41.44, 41.78, 42.11, 42.44, 42.78, 43.11, 43.44,
43.78, 44.11, 44.44, 44.77, 45.11, 45.44, 45.77, 46.11,
46.44, 46.77, 47.11, 47.44, 47.77, 48.10, 48.44, 48.77,
49.10, 49.44, 49.77, 50.10, 50.44, 50.77, 51.10, 51.43,
51.77, 52.10, 52.43, 52.77, 53.10, 53.43, 53.77, 54.10,
54.43, 54.76, 55.10, 55.43, 55.76, 56.10, 56.43, 56.76,
57.10, 57.43, 57.76, 58.09, 58.43, 58.76, 59.09, 59.43,
59.76 ;
}