GSD Sounding Format Description

                          GSD Sounding data format

The official GSD data format is similar to the format used by the National
Severe Storms Forecast Center (NSSFC) in Kansas City.  The first 4 lines of 
the sounding are identification and information lines. All additional lines 
are data lines.  An entry of 32767 (original format) or 99999 (new format) 
indicates that the information is either missing, not reported, or not 

NOTE: For AMDAR data, there is an additional line at the top of each
sounding that looks something like this:

A:  DEN AC#  533 U/D -1 N: 29 B: 125 R:  150 Secs 931472580 DT: 2

"A:" identifies this as an AMDAR sounding.
"DEN" is the airport.
"AC# 533" is the Aircraft Number (GSD's own aircraft ID scheme)
"U/D -1" indicates this is a descent sounding (1 for ascent);
"N: 29" indicates there are 29 levels in the sounding
"B: 125 R: 150" indicates that the highest data point had a bearing
                and range from the airport of 125 degrees and 150
                nautical miles.
"Secs 931472580" indicates that this sounding left (or reached) the
                 ground this many seconds after 0000 UTC on  1/1/70.
"DT: 2" indicates the "data type" pf the aircraft, as follows
        0 - measures wind and temperature only
	1 - measures vertical acceleration, wind and temperature
	2 - measures eddy dissipation rate, wind and temperature
	3 - measures dewpoint, wind, and temperature

In addition, for AMDAR and RAOB data lines, there are 3 additional columns (8-10)
that display hour/minute, bearing, and range from the airport or launch site. 

                            ---COLUMN NUMBER---

      1          2          3          4          5          6           7      8       9    10
                                header lines
   TYPE        HOUR        DAY      MONTH       YEAR    (blank)     (blank)
      1       WBAN#       WMO#        LAT        LON       ELEV       RTIME
      2       HYDRO       MXWD      TROPL      LINES     TINDEX      SOURCE
      3     (blank)      STAID    (blank)    (blank)      SONDE     WSUNITS
                                data lines


LINTYP: type of identification line
       TYPE = indicates the type of sounding
		RAOB, Model-name, ACARS, RADIO, etc.
          1 = station identification line 
          2 = sounding checks line
          3 = station identifier and other indicators line
          4 = mandatory level 
          5 = significant level
          6 = wind level (PPBB) (GTS or merged data) 
          7 = tropopause level (GTS or merged data)
          8 = maximum wind level (GTS or merged data)
          9 = surface level

HOUR:   time of report in UTC
LAT:    latitude in degrees and hundredths
LON:    longitude in degrees and hundredths
ELEV:   elevation from station history in meters
RTIME:  is the actual release time of radiosonde from TTBB. Appears in GTS data
HYDRO:  the pressure of the level to where the sounding passes the hydrostatic
        check (see section 4.3).**
MXWD:   the pressure of the level having the maximum wind in the sounding.  If
        within the body of the sounding there is no "8" level then
        MXWN is estimated (see section 3.2).
TROPL:  the pressure of the level containing the tropopause. If within the
        body of the sounding there is no "7" level, then TROPL is estimated
        (see section 3.3)** 
LINES:  number of levels in the sounding, including the 4 identification lines.
TINDEX: indicator for estimated tropopause. A "7" indicates that sufficient
        data was available to attempt the estimation; 11 indicates that data
        terminated and that tropopause is a "suspected" tropopause.
SOURCE: 0 = National Climatic Data Center (NCDC)
        1 = Atmospheric Environment Service (AES), Canada
        2 = National Severe Storms Forecast Center (NSSFC)
        3 = GTS or GSD GTS data only
        4 = merge of NCDC and GTS data (sources 2,3 merged into sources 0,1)
SONDE:  type of radiosonde code from TTBB. Only reported with GTS data
        10 = VIZ "A" type radiosonde
        11 = VIZ "B" type radiosonde
        12 = Space data corp.(SDC) radiosonde.
WSUNITS:wind speed units (selected upon output)
        ms = tenths of meters per second
        kt = knots

PRESSURE: in whole millibars (original format)
          in tenths of millibars (new format)
HEIGHT:   height in meters (m)
TEMP:     temperature in tenths of degrees Celsius
DEWPT:    dew point temperature in tenths of a degree Celsius
WIND DIR: wind direction in degrees
WIND SPD: wind speed in knots
HHMM:     hour and minute (UTC) that this data line was taken
          (for RAOBS, estimated by assuming a 5 m/s ascent rate).
BEARING: Bearing from the ground point for this level
RANGE:   Range (nautical miles) from the ground point for this level.

An example of fortran format statements necessary to read output rawinsonde
data, according to LINTYP, is as follows:

                       254    (3i7,6x,a4,i7)
                         1    (3i7,2f7.2,2i7)
                         2    (7i7)
                         3    (i7,10x,a4,14x,i7,5x,a2)
               4,5,6,7,8,9    (10i7) 

**- section of noaa tech memo on the data base (in print)

 TECHNICAL INFORMATION: Schwartz, B.E., and M. Govett, 1992: "A hydrostatically
  consistent North American Radiosonde Data Base at the forecast Systems
  Laboratory, 1946-present." NOAA Technical Memorandum ERL FSL-4. Available
  from NOAA/ERL/FSL 325 Broadway, Boulder, CO 80303.

Prepared by Mark Govett, and Bill Moninger
Last modified: Thu Aug 16 13:29:06 DST 2007