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20000525: Creating GEMPAK sounding files from sounding files in an ascii format

Darren,

The default maximum number of levels for a sounding LLMXLV is
defined in the $GEMPAKHOME/include/gemprm.xxx files as 500 as
a compile time setting. So, at present, you can't stick in 2000 to 6000
levels unless you completely recompile GEMPAK.

Since the primary vertical coordinate is pressure, your duplicates
(eg 1011.7mb for the first 2 levels) should be filtered out as well
(even though they have different altitudes). Generally, you might 
be able to pare the data down using values every 1 mb below 850mb and
every 2 millibars above 850 (if you have data in the 1020mb to 200mb range).

Input text files for snedit can have multiple times and stations
in the same file, and the resulting GEMPAK file can have the same-
so long as the same station ID only has 1 sounding per sounding time.
If you have multiple soundings for the same location and time, then you should
assign them different station IDs.

You can mix in WMO soundings, and create a station table with both
existing and bogus field site ids for use with sncfil. 


Let me know if you need more information.

Steve Chiswell
Unidata User Support



>From: Darren Gallant <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200005251902.e4PJ2hT13055

>Dear Unidata Support,
>
>I want to create GEMPAK sounding files from soundings in an ascii format.
>First the files represent high resolution rawindsonde with data in the
>vertical every few seconds. Below is an example portion of the files I
>wish to convert to the GEMPAK sounding format.
>
>Data Type:                         High Resolution Sounding
>Project ID:                        INDOEX
>Release Site Type/Site ID:         Kaashidhoo KAA
>Release Location (lon,lat,alt):     73 27.96'E,  4 57.90'N,   73.47,
>4.96,     1.0
>UTC Release Time (y,m,d,h,m,s):    1999, 02, 26, 06:30:90
>Sonde Type/ID/Sensor ID/Tx Freq:   VAISALA RS80-15GH 902701002, 0, 402.800
>Met Processor/Met Smoothing:       NCAR RS80 Processor, 10SECONDS
>Winds Type/Processor/Smoothing:    GPS, Vaisala MWG201, 40SECONDS
>System Operator/Comments:          ackerman, hot and hazy
>Input File:                        y2260627.kaa
>/
>Nominal Release Time (y,m,d,h,m,s):1999, 02, 26, 06:30:90
> Time  Press  Temp  Dewpt  RH    Ucmp   Vcmp   spd   dir   Wcmp     Lon
>Lat   Ele   Azim   Alt    Qp   Qt   Qrh  Qu   Qv   QdZ
>  sec    mb     C     C     %     m/s    m/s   m/s   deg   m/s      deg
>deg   deg   deg     m    code code code code code code
>------ ------ ----- ----- ----- ------ ------ ----- ----- ----- --------
>------- ----- ----- ------- ---- ---- ---- ---- ---- ----
>  -1.0 1011.7  30.8  25.0  70.7   -0.2   -1.4   1.4   8.0 999.0 9999.000
>999.000 999.0 999.0     1.0 99.0 99.0 99.0 99.0 99.0  9.0
>   0.0 1011.7  30.7  24.8  70.2   -0.2   -1.4   1.4   7.6 999.0   73.466
>4.965 999.0 999.0     1.0  3.0  3.0  3.0 99.0 99.0  9.0
>   1.0 1010.5  30.3  24.4  70.3 9999.0 9999.0 999.0 999.0  10.6   73.466
>4.965 999.0 999.0    11.6  3.0  3.0  3.0  9.0  9.0 99.0
>   2.0 1010.0  29.8  24.0  70.5 9999.0 9999.0 999.0 999.0   4.7   73.466
>4.965 999.0 999.0    16.3  3.0  3.0  3.0  9.0  9.0 99.0
>   3.0 1009.5  29.2  23.6  71.0 9999.0 9999.0 999.0 999.0   4.6   73.466
>4.965 999.0 999.0    20.9  3.0  3.0  3.0  9.0  9.0 99.0
>   4.0 1008.8  28.7  23.2  71.7   -0.2   -1.2   1.2  12.0   5.5   73.466
>4.965 999.0 999.0    26.4  3.0  3.0  3.0 99.0 99.0 99.0
>   5.0 1008.2  28.3  23.0  72.6 9999.0 9999.0 999.0 999.0   5.9   73.466
>4.965 999.0 999.0    32.3  3.0  3.0  3.0  9.0  9.0 99.0
>   6.0 1007.4  28.0  23.0  73.6 9999.0 9999.0 999.0 999.0   6.7   73.466
>4.965 999.0 999.0    39.0  3.0  3.0  3.0  9.0  9.0 99.0
>   7.0 1006.5  27.8  23.0  74.7 9999.0 9999.0 999.0 999.0   8.0   73.466
>4.965 999.0 999.0    47.0  2.0  2.0  2.0  9.0  9.0 99.0
>
>Unfortunately the lines wrap around. Of course the header section wouldn't
>be included in the GEMPAK files. In the data section, I only want to
>encode the typical parameters: pressure, dry bulb temp, relative humidity,
>dew point, total wind speed and direction, altitude.   
>
>Is there a limit to the number of levels contained in a GEMAPK sounding
>file? Our soundings typically have between 2000 to 6000 levels
>
>Can a GEMPAK sounding file contail multiple soundings from the same site
>and/or many soundings from different sites?
>
>If my rawindsonde sites include NWS and other WMO recognized upper air
>stations can I use snstns.tbl? I'm sure I can add stations to it if
>needed.
> 
>Thanks
>
>
>Darren R. Gallant              UCAR/JOSS
>Programmer/Technician           Joint OfFice Of Science Support
>303-497-2634                    P.O. Box 3000
>address@hidden                Boulder,CO 80307-30000
>
>