Processed Dropwindsonde Observations in FRD Format

HRD's Full-Resolution Data (FRD) files are the output from the data received from HRD's Editsonde program as used either on our onboard computer during a flight or, more likely, in post-flight quality control processing. It is in a standardized ASCII format. Each file begins with a header identifying the sonde, the date and time the sonde was processed. There follows several lines identifying the processing parameters, such as filters and bias corrections that have been applied as well as processor comments. The next block contains the launch information, such as time and location of launch and flight level temperature, pressure and geopential altitude at the aircraft at time of launch. The main body of data follows begining with a header line listing each column parameter and units. Each line of data will contain the observation sequential number, elapsed time, the meteorological observations, as well as the latitude, longitude, and altitude as determined by the sonde's GPS navigation chip. The usual time interval between observations is one half second.

Example

 ===========================================================================
 DROPWINDSONDE PROCESSING RECORD                            Sonde: 053716110
 PDS file written Sep 21, 2007.                             Format:    V6.05
 Aircraft: N42RF                             Date: 070921   Time: 183312 UTC
 ---------------------------------------------------------------------------
 Bias corrections:  PR =    .0 mb  TE =    .0 C  RH =    .0 %  PRB =   .4 mb
 Filters (LPF):     PTH =  10 s    WIND =  10 s       Hyd anchor =       SFC
 Dyn RH correction =  N     WSHR COR =      Y         Splash PR  = 1008.6 mb
 Estimated PR used =  N     GPS VERR =    .15 m/s     HYD SFCP   = 1010.3 mb
 Dyn T correction  =  Y     WGACORR  =   -1.6 m       AC GA ADJ  =     .0 m
 ---------------------------------------------------------------------------
 COMMENTS: None                                                        
 ===========================================================================

 ==============================================================================
 Date: 070921   Lat:  29.14 N   TA:   16.1 C   PS:  844.3 mb   WD:   350 deg
 Time: 183312   Lon:  87.29 W   TD: -999.0 C   GA:   1554 m    WS:   8.8 m/s
 SID:  053716110                RH: -999.0 %   Navaid:   GP          
 ===========================================================================

IX      t (s)  P (mb)    T (C)    RH (%)  Z (m)   WD    WS (m/s)   U (m/s)   V (m/s)  NS  WZ (m/s)  ZW (m)   FP  FT  FH  FW   LAT (N)    LON (E)  ZW (ft)  WS (kt)  WS (mph)  THETAE (K)
0001      .3   844.9     16.13   -999.0    1541   351     8.71      1.34     -8.61  -999  -999.0    1540     3   3   0   3    29.1439   -87.2948     5052    16.91     19.52     -999.00
0002      .8   845.4     16.18   -999.0    1536   354     8.44       .84     -8.40  -999  -999.0    1534     3   3   0   3    29.1438   -87.2948     5033    16.38     18.91     -999.00
0003     1.3   846.0     16.21   -999.0    1530   355     8.36       .70     -8.34  -999  -999.0    1528     3   3   0   3    29.1438   -87.2948     5014    16.23     18.74     -999.00
0004     1.8   846.6     16.25   -999.0    1524   356     8.29       .55     -8.27  -999  -999.0    1523     3   3   0   3    29.1437   -87.2948     4995    16.08     18.57     -999.00

Please contact Sim Aberson or Mike Black if you have any questions about FRD format.

Last modified: 23 May 2008.
Please report any problems to the HRD webmaster.