How does zyGrib figure out datum of source grib?
Posted: 10 Feb 2017 00:46
I'm downloading a subsetted grib from the following location: http://nomads.ncep.noaa.gov/cgi-bin/fil ... 2017020912
This file renders perfectly in zyGrib, and I'm curious how zyGrib is able to correctly figure out the datum for this grib.
When I look at gdalinfo, the datum seems to be invalid (see below).
Can anyone tell me how zyGrib does its magic to resolve this unknown datum?
This file renders perfectly in zyGrib, and I'm curious how zyGrib is able to correctly figure out the datum for this grib.
When I look at gdalinfo, the datum seems to be invalid (see below).
Can anyone tell me how zyGrib does its magic to resolve this unknown datum?
Code: Select all
gdalinfo gfs.t12z.pgrb2.0p25.f001
Driver: GRIB/GRIdded Binary (.grb)
Files: gfs.t12z.pgrb2.0p25.f001
Size is 241, 105
Coordinate System is:
GEOGCS["Coordinate System imported from GRIB file",
DATUM["unknown",
SPHEROID["Sphere",6371229,0]],
PRIMEM["Greenwich",0],
UNIT["degree",0.0174532925199433]]
Origin = (233.875000000000000,50.125000000000000)
Pixel Size = (0.250000000000000,-0.250000000000000)
Corner Coordinates:
Upper Left ( 233.875, 50.125) (233d52'30.00"E, 50d 7'30.00"N)
Lower Left ( 233.875, 23.875) (233d52'30.00"E, 23d52'30.00"N)
Upper Right ( 294.125, 50.125) (294d 7'30.00"E, 50d 7'30.00"N)
Lower Right ( 294.125, 23.875) (294d 7'30.00"E, 23d52'30.00"N)
Center ( 264.000, 37.000) (264d 0' 0.00"E, 37d 0' 0.00"N)
Band 1 Block=241x1 Type=Float64, ColorInterp=Undefined
Description = 92500[Pa] ISBL="Isobaric surface"
Metadata:
GRIB_COMMENT=Relative Humidity [%]
GRIB_ELEMENT=RH
GRIB_FORECAST_SECONDS=3600 sec
GRIB_PDS_PDTN=0
GRIB_PDS_TEMPLATE_NUMBERS=1 1 2 0 96 0 0 0 1 0 0 0 1 100 0 0 1 105 84 255 0 0 0 0 0
GRIB_REF_TIME= 1486641600 sec UTC
GRIB_SHORT_NAME=92500-ISBL
GRIB_UNIT=[%]
GRIB_VALID_TIME= 1486645200 sec UTC