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For this page:
INTERNAL LINKS
THE NERC MST RADAR FACILITY AT ABERYSTWYTH
FILE FORMAT (BINARY) FOR VERSION-0 MST RADAR TIME-AVERAGED POWER 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 contain radar return signal power data derived from Doppler spectra averaged over 12 minutes. The same data are stored in ASCII format files - please contact the NERC MST Radar Facility Project Scientist for more details.
Click here to find out about the contents of other files.

File naming convention:
pwfYYMMDD.dat

YY is a 2-digit year [00 - 99]
MM is a 2-digit month [01 - 12]
DD is a 2-digit day [01 - 31]
Click here for the background to the file naming convention.

File location: /badc/mst/data/mst-products-v0/power/
Click here for the location of other files.

Archiving convention: YYYY
Click here for a further explanation.

File availability
1990 to the present.

File format
The data are recorded in non-standard format binary files as descibed below:

                        POWER FILES
                        -----------

        File name :- PWFyyMMdd.DAT

        RANDOM ACCESS FILE  -  UNFORMATTED
        RECORD = 32 BYTES
        
        B = BYTE
        I2 = INTEGER*2 (2 byte integer)


        DATA IN POWER (PWF) FILE
        ------------------------
        
        The file contains power data obtained from all the Doppler 
        spectra files collected on one day.

        A Parameter Block for each dwell (beam direction) contains
        most of the information from the corresponding parameter block
        in the Doppler Spectra file. 
        It also contains additional information required for file management.
        
        Each Power Data value is the summation of all the values in
        the Doppler spectrum obtained for one height.
        The spectra are for one dwell (ie one beam direction). 
        Power Data values require one byte for each height bin and are
        expressed as the power to the nearest dB.

        The data starts at bin number NH1 and continues to NH2 followed by 
        NH3 to NH4 if any upper height data was collected in that dwell.
        If there is upper height data then NH3 > NH2. Otherwise NH3 = 0.


        RECORD ORDERING
        ---------------

        PARAMETER BLOCK             One record containing Dwell Parameters
        DATA RECORDS                N records, each with 32 Power values
        PARAMETER BLOCK             Parameters for next dwell 
        DATA RECORDS                Power values for next dwell
          etc.

        N = 1 + INT(( total number of bins per dwell - 1 ) / 32)
        

        RECORD FORMATS
        --------------

        Parameter Block ( PB ) ( Start of Each Dwell )
        ----------------------

          Length of Transmitter pulse ( microsec ).          LTX     B 
          Pulse Code Resolution.                             NCC     B 
            0 = Uncoded , 1 = 8 uS , 2 = 4 uS
            3 = 2 uS , 4 = 1 uS 
          Pulse Repetion Interval ( microsec ).              IPI     I2
          Number of Coherent Pulse Additions.                NPP     I2
          Length of FFT.                                     LFT     I2
          Number of FFTs Averaged together.                  NAV     B
          Beam Number.                                       NBM     B
          Receiver Filter (microsec) (1/bandwidth).          NRX     B 
          Raw Data Collection Flag.                          DMP     B 
            Negative value if Raw Data File Collected.
          YEAR in Form 90,91,92 etc.                         IY      B
          MONTH ( 1 - 12 ).                                  IMN     B
          DAY ( 1 - 31 ).                                    ID      B
          HOUR ( 0 - 23 ).                                   IH      B
          MINUTE ( 0 - 59 ).                                 IM      B
          SECONDS ( 0 - 59 ).                                IS      B
          Start of First Height Range  ( Bin No. ).          NH1     I2
          End of First Height Range    ( Bin No. ).          NH2     I2
          Start of Second Height Range ( Bin No. ).          NH3     I2
          End of Second Height Range   ( Bin No. ).          NH4     I2
          Run Number.                                        MST     I2
          No. of Cycles * 10 + No. of Dwells in observation. NCD     I2
          No. of Records / Cycle.                            NRC     I2

        Data Record
        -----------

          Power value (dB)                                                 B
            1 byte / height bin.
            32 power values per record. 
            N records per dwell                
            Last record of a dwell usually has less than 32 power values.



        HEIGHT DERIVATION
        -----------------

	Height at range bin n is given by :-  Ht = (n - Bz) * HI

	Bz is the sea level range bin,
          derived as follows from dwell header parameters:
	NRX = Receiver filter (microsecs).
	LTX = Transmitter pulse width (microsecs).
	If NRX = 1  Bz = 5.7 ( unless LTX = 1 when Bz = 5.2 )
	If NRX = 2  Bz = 6.7
	If NRX = 4  Bz = 8.7
	If NRX = 8  Bz = 12.7

	HI is the height increment per bin.
          derived as follows from dwell header parameter:
	NBM = Antenna beam number.
	If NBM = 0               HI = 0.15 Km.    ( Vertical )
	If NBM = 1,3,5 or 7      HI = 0.1496 Km.  ( 4.2 Deg. )
	If NBM = 2,4,6 or 8      HI = 0.1484 Km.  ( 8.5 Deg. )
	If NBM = 9,11,13 or 15   HI = 0.1492 Km.  ( 6.0 Deg. )
	If NBM = 10,12,14 or 16  HI = 0.1467 Km.  ( 12.0 Deg.)


          Last update of this description 16 February 1995.

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