| Subject: | Unable to read NCEP-Gribs spanning whole world with lon = 0..-1 |
| Date: | Thu, 14 Apr 2011 12:17:59 +0200 |
| To: | bug-Geo-ReadGRIB [...] rt.cpan.org |
| From: | Stephan Weinberger <sweinberger [...] ubimet.com> |
Geo::ReadGrib 1.4 seems to incorrectly read longitude values when they span
from 0 to -1 (360° 'wrapped around') like in NCEP worldwide gribs.
Following is the output on a grib consisting of 0-180hr fcst records
downloaded from
http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.YYYYMMDDHH/gfs.tHHz.pgrbf*
and combined (via cat) into one file:
$grib->show():
---------------------------------------------------------
Locations:
lat: 90 to -90
long: 0 to -1
Times:
Wed Apr 13 18:00:00 2011 (1302717600) to Fri May 20 00:00:00 2016
(1463702400)
Types:
4LFTX: Best (4-layer) lifted index [K]
ACPCP: Convective precipitation [kg/m^2]
APCP: Total precipitation [kg/m^2]
CSNOW: Categorical snow [yes=1;no=0]
PRMSL: Pressure reduced to MSL [Pa]
RH: Relative humidity [%]
TCDC: Total cloud cover [%]
TMAX: Max. temp. [K]
TMIN: Min. temp. [K]
TMP: Temp. [K]
UGRD: u wind [m/s]
VGRD: v wind [m/s]
---------------------------------------------------------
grib->extract('TMAX', 0.5, 0.5):
---------------------------------------------------------
extract(): LONG: >0.5< out of range 0 to -1
---------------------------------------------------------
grib->extract('TMAX', 0.5, -0.5):
---------------------------------------------------------
extract(): LONG: >-0.5< out of range 0 to -1
---------------------------------------------------------
wgrib -V:
---------------------------------------------------------
[...]
rec 4:260890:date 2011041312 TMAX kpds5=15 kpds6=105 kpds7=2 levels=(0,2)
grid=3 2 m above gnd valid 0-6hr:
TMAX=Max. temp. [K]
timerange 2 P1 0 P2 6 TimeU 1 nx 360 ny 181 GDS grid 0 num_in_ave 0 missing
0
center 7 subcenter 0 process 96 Table 2
latlon: lat 90.000000 to -90.000000 by 1.000000 nxny 65160
long 0.000000 to -1.000000 by 1.000000, (360 x 181) scan 0 mode 128
bdsgrid 1
min/max data 210.2 322.5 num bits 11 BDS_Ref 2102 DecScale 1 BinScale 0
[...]
rec 439:36428326:date 2011041312 TMAX kpds5=15 kpds6=105 kpds7=2 levels=(0,2)
gr
id=3 2 m above gnd valid 174-180hr:
TMAX=Max. temp. [K]
timerange 2 P1 174 P2 180 TimeU 1 nx 360 ny 181 GDS grid 0 num_in_ave 0
missi
ng 0
center 7 subcenter 0 process 96 Table 2
latlon: lat 90.000000 to -90.000000 by 1.000000 nxny 65160
long 0.000000 to -1.000000 by 1.000000, (360 x 181) scan 0 mode 128
bd
sgrid 1
min/max data 210 320.1 num bits 11 BDS_Ref 2100 DecScale 1 BinScale 0
[...]
---------------------------------------------------------
--
Stephan Weinberger, BSc
IT
UBIMET GmbH
Dresdner Straße 82
A 1200 Wien
Tel +43 1 99 71 004 - 38
Fax +43 1 99 71 004 - 20
sweinberger@ubimet.com
www.unwetterzentrale.at
www.ubimet.com