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For this page:
INTERNAL LINKS
THE NERC MST RADAR FACILITY AT ABERYSTWYTH
FILE FORMAT (ASCII) FOR VERSION-0 MST RADAR WIND DATA
WARNING: Version-0 MST radar data products are DEPRECATED
Users are encouraged to make use of Version-2 Cartesian files.
Click here to find out more about the different versions of the signal processing.

File contents
These files contain profiles of the eastward, northward and upward components of the wind. The same format is used for both unaveraged and 12 minute averaged data files.
Click here to find out about the contents of other files.

File naming convention:
Unaveraged vhYYMMDD.gz
12 minute averaged vecYYMMDD.gz

YY is a 2-digit year [00 - 99]
MM is a 2-digit month [01 - 12]
DD is a 2-digit day [01 - 31]
gz indicates that the file is compressed with the GNU gzip algorithm

Click here for the background to the file naming convention, and here for to find out how to deal with compressed files.
NOTE for Windows-based users. WinZip gives rise to an unexpected change of name from vhYYMMDD.gz to vecYYMMDD when uncompressing (owing to the fact that the original file was first compressed, and then renamed). It is not, therefore, possible to distinguish between uncompressed files for unaveraged and 12 minute averaged wind data based on the name. This problem is not encountered on Linux/Unix systems.

File location:
Unaveraged /badc/mst/data/mst-products-v0/vw/
12 minute averaged /badc/mst/data/mst-products-v0/vector/
Click here for the location of other files.

Archiving convention: YYYY
Click here for a further explanation.

File availability
1989 to the present.

File format
The data are recorded in non-standard ASCII format files. The first twelve lines of the (unaveraged data) file for 3rd September 2001 are shown below by way of example below:


 1  0.80  1  1  1  1    4.0
  Lat.     Long.  Height  Freq_Mhz    Site
 52.400   -4.000   50.0    46.50    Capel Dewi.
 Run  1265  vw010903_0020.22
 Dw Beam      Date     Time      Bins     Bins   Tx Rx   Pri  Sum FFT Avg
  1  NE6 D2001/09/03 Z00:20:50 L018:147 U000:000  8  2   320  512 128  1
  3  VRT D2001/09/03 Z00:21:38 L017:147 U000:000  8  2   320 1024  64  1
  4  SE6 D2001/09/03 Z00:22:01 L018:147 U000:000  8  2   320  512 128  1
    Km    East  North  Vert.  m/s  Heights= 120
   1.70  -2.93 -22.11   1.55
   1.85  -4.39 -22.04   1.80
   2.00   6.05 -11.82   1.13
In the explanations of the different file components below, some of the horizontal spacings have been altered for the sake of clarity. The text shown in red is for descriptive purposes only and does not appear in the files. The first 5 (header) lines, shown only once at the very beginning of each file, do not contain any information needed to extract or to interpret the data and so can be ignored.

 1  0.80  1  1  1  1    4.0
  Lat.     Long.  Height  Freq_Mhz    Site
 52.400   -4.000   50.0    46.50    Capel Dewi.
 Run  1265  vw010903_0020.22
 Dw Beam      Date     Time      Bins     Bins   Tx Rx   Pri  Sum FFT Avg
Wind profiles are calculated by combining the information from observations made in the vertical direction and at an off-vertical angle in two orthogonal azimuths. The next three lines contain the radar observation information for the three beam pointing directions used. Only the observation times are actually required to make use of the data. Since these times are typically within a couple of minutes of each other, it is aribitrary whether the profile time is taken to correspond to the first of these, the average or the middle value. Since a radar observation cycle typically involves more than three beam pointing directions, a profile is calculated for each possible combination. This means that for 12 minute averaged data, there will typically be two or three profiles within a few minutes of each other and then a gap of almost 12 minutes before the next set of profiles.

1   NE6 D2001/09/03 Z00:20:50 L018:147 U000:000  8     2     320  512   128    1
3   VRT D2001/09/03 Z00:21:38 L017:147 U000:000  8     2     320 1024    64    1
4   SE6 D2001/09/03 Z00:22:01 L018:147 U000:000  8     2     320  512   128    1
DWL BD   YYYY/MM/DD  hh:mm:ss  RG1:RG2  RG3:RG4  PLEN  RXBW  IPP  NCI  LDFT  NII
DWL - Dwell number, i.e. the dwell position in the sequence of observations made during each cycle
BD - Nominal beam pointing direction
YYYY/MM/DD - Observation date (year/month/day)
hh:mm:ss - UT observation time (hour:minute:second)
RG1:RG2 - Bottom and top range gates of the lower observation region
RG3:RG4 - Bottom and top range gates of the upper observation region (equal to zero for ST mode observations)
PLEN - Pulse length (us)
RXBW - Receiver bandwidth (us)
IPP - Inter-pulse period (us)
NCI - Number of coherent integrations
LDFT - Length of discrete Fourier transform
NII - Number of incoherent integrations
The next block of lines (of which only the first 4 are shown) contains the three components of the wind vector as a function of altitude. Although the radar return signal is sampled every 150 m in range, data are only given in this file at range gates for which the signal is sufficiently strong for the Doppler shift values to be considered reliable. The number of range gates for each cycle is given in the first line of the block - Heights= 120 - i.e. there are 120 lines of data for this particular cycle.

    Km    East  North  Vert.  m/s  Heights= 120
   1.70  -2.93 -22.11   1.55
   1.85  -4.39 -22.04   1.80
   2.00   6.05 -11.82   1.13
   z      u     v       w
z - Altitude (km)
u - Zonal velocity (m s-1), i.e. component of wind vector towards East (+ve)
v - Meridional velocity (m s-1), i.e. component of wind vector towards North (+ve)
w - Vertical velocity (m s-1), i.e. component of wind vector upwards (+ve)
Internal Links:
Return to the top of the page
Gaining access to the data
File naming convention
Data archiving convention
Data locations
The differences between signal processing versions
The contents of other data files
Page maintained by David Hooper
Last updated 22nd March 2005