Problem in writing .ctl file for global GRIB file
Elif SERTEL
esertel at ENVSCI.RUTGERS.EDU
Mon Feb 4 10:16:56 EST 2008
Did you try grib2ctl?
http://www.cpc.ncep.noaa.gov/products/wesley/grib2ctl.html
Elif.
On Mon, February 4, 2008 3:54 am, PHUONG NGUYEN wrote:
> Dear GRADS users,
> I have a global GRIB file. I would like to write the
> .ctl file for plotting it.
>
> I use wgrib to see it structure. Based on the results
> I can write a . ctl file as the following :
>
> dset ^a01150000
> index ^a01150000.idx
> undef 9.999E+20
> title a01150000
> dtype grib 41
> xdef
> ydef
> tdef 1 linear 00Z15jan2008 1mo
> zdef 10 levels
> 850 700 600 500 400 300 250 200 150 100
> vars 10
> HGTprs 10 7,100,0 ** Geopotential height [gpm]
> HGTmwl 0 7,6,0 ** max wind level Geopotential height
> [gpm]
> HGTtrp 0 7,7,0 ** tropopause Geopotential height
> [gpm]
> RHprs 4 52,100,0 ** Relative humidity [%]
> TMPprs 10 11,100,0 ** Temp. [K]
> TMPtrp 0 11,7,0 ** tropopause Temp. [K]
> UGRDprs 10 33,100,0 ** u wind [m/s]
> UGRDmwl 0 33,6,0 ** max wind level u wind [m/s]
> VGRDprs 10 34,100,0 ** v wind [m/s]
> VGRDmwl 0 34,6,0 ** max wind level v wind [m/s]
> ENDVARS
>
> The problem is in writing xdef and ydef : it is global
> file :
>
> rec 1:41:date 2008011500 HGT kpds5=7 kpds6=100
> kpds7=850 levels=(3,82) grid=41 850 mb 6hr fcst:
> HGT=Geopotential height [gpm]
> timerange 0 P1 6 P2 0 TimeU 1 nx -1 ny 73 GDS grid
> 0 num_in_ave 0 missing 0
> center 74 subcenter 0 process 45 Table 2
> thinned latlon: lat -90.000000 to 0.000000 by
> 1.250000 nxny 3447
> long -30.000000 to 60.000000, 3447 grid pts
> (-1 x 73) scan 64 mode 128 bdsgrid 1
> 2 3 5 6 8 9 11 12 14 16
> 17 19 20 22 23
> 25 26 28 29 30 32 33 35 36 38
> 39 40 42 43 44
> 45 47 48 49 50 51 52 54 55 56
> 57 58 59 60 60
> 61 62 63 64 65 65 66 67 67 68
> 69 69 70 70 71
> 71 71 72 72 72 73 73 73 73 73
> 73 73 73
> min/max data 959.999 1580 num bits 10 BDS_Ref
> 959.999 DecScale 0 BinScale 0
>
> rec 2:4624:date 2008011500 HGT kpds5=7 kpds6=100
> kpds7=850 levels=(3,82) grid=42 850 mb 6hr fcst:
> HGT=Geopotential height [gpm]
> timerange 0 P1 6 P2 0 TimeU 1 nx -1 ny 73 GDS grid
> 0 num_in_ave 0 missing 0
> center 74 subcenter 0 process 45 Table 2
> thinned latlon: lat -90.000000 to 0.000000 by
> 1.250000 nxny 3447
> long 60.000000 to 150.000000, 3447 grid pts
> (-1 x 73) scan 64 mode 128 bdsgrid 1
> 2 3 5 6 8 9 11 12 14 16
> 17 19 20 22 23
> 25 26 28 29 30 32 33 35 36 38
> 39 40 42 43 44
> 45 47 48 49 50 51 52 54 55 56
> 57 58 59 60 60
> 61 62 63 64 65 65 66 67 67 68
> 69 69 70 70 71
> 71 71 72 72 72 73 73 73 73 73
> 73 73 73
> min/max data 1038 1571 num bits 10 BDS_Ref 1038
> DecScale 0 BinScale 0
>
> rec 3:9207:date 2008011500 HGT kpds5=7 kpds6=100
> kpds7=850 levels=(3,82) grid=43 850 mb 6hr fcst:
> HGT=Geopotential height [gpm]
> timerange 0 P1 6 P2 0 TimeU 1 nx -1 ny 73 GDS grid
> 0 num_in_ave 0 missing 0
> center 74 subcenter 0 process 45 Table 2
> thinned latlon: lat -90.000000 to 0.000000 by
> 1.250000 nxny 3447
> long 150.000000 to -120.000000, 3447 grid
> pts (-1 x 73) scan 64 mode 128 bdsgrid 1
> 2 3 5 6 8 9 11 12 14 16
> 17 19 20 22 23
> 25 26 28 29 30 32 33 35 36 38
> 39 40 42 43 44
> 45 47 48 49 50 51 52 54 55 56
> 57 58 59 60 60
> 61 62 63 64 65 65 66 67 67 68
> 69 69 70 70 71
> 71 71 72 72 72 73 73 73 73 73
> 73 73 73
> min/max data 929.963 1632.96 num bits 10 BDS_Ref
> 929.963 DecScale 0 BinScale 0
>
> rec 4:13790:date 2008011500 HGT kpds5=7 kpds6=100
> kpds7=850 levels=(3,82) grid=44 850 mb 6hr fcst:
> HGT=Geopotential height [gpm]
> timerange 0 P1 6 P2 0 TimeU 1 nx -1 ny 73 GDS grid
> 0 num_in_ave 0 missing 0
> center 74 subcenter 0 process 45 Table 2
> thinned latlon: lat -90.000000 to 0.000000 by
> 1.250000 nxny 3447
> long -120.000000 to -30.000000, 3447 grid
> pts (-1 x 73) scan 64 mode 128 bdsgrid 1
> 2 3 5 6 8 9 11 12 14 16
> 17 19 20 22 23
> 25 26 28 29 30 32 33 35 36 38
> 39 40 42 43 44
> 45 47 48 49 50 51 52 54 55 56
> 57 58 59 60 60
> 61 62 63 64 65 65 66 67 67 68
> 69 69 70 70 71
> 71 71 72 72 72 73 73 73 73 73
> 73 73 73
> min/max data 1023.33 1632.33 num bits 10 BDS_Ref
> 1023.33 DecScale 0 BinScale 0
>
>
> Above there are 4 first records : lat changes from -90
> to 0 by 1.25, lon changes in each record (for example,
> in rec 1 : lon -30 60, in rec 2 : lon 60 150, etc),
> and nx -1, ny 73, nxny 3447 grid pts.
>
> Then from rec 5 to rec 8 the lat changes from 0 to 90
> by 1.25, and the lon changes as in each rec above.
>
> So how to write the xdef and ydef in this case ???
> Please help me.
> Thank you very much.
> Phuong
>
>
> MS NGUYEN THI MINH PHUONG
> National Center for Hydrometeorological Forecasts
> Address: 4 DANG THAI THAN, HANOI, VIETNAM,
> Email : ntmphuong at hotmail.com, ntmphuong at yahoo.com.au
> ======
>
>
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--
Visiting Fulbright Researcher
Rutgers University
Department of Environmental Sciences
http://www.envsci.rutgers.edu/~esertel/
Res. and Teach. Assist. Elif SERTEL
Istanbul Technical University
Civil Engineering Faculty,
Remote Sensing Division
http://www.ins.itu.edu.tr/esertel/
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