LF data format Ver. 2.x

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High time resolution time series

  • File name: rrrYYYYMMDDHH.dat.0.gz (rrr: station name)
  • Format gzipped-ascii file
  • Time resolution : 0.1sec
  • Structure of the data
    block contents
    1st block header block (header block size is the same as data block size)
    2nd block data block1 : data measured from HH:00:00.0 to HH:00:00.9
    3rd block data block2 : data measured from HH:00:01.0 to HH:00:01.9
    …
    3601th block data block3600: data measured from HH:59:59.0 to HH:59:59.9
  • Size of each block : Number of frequency channel x 20 x 2Byte + 4Byte
  • Header block format
    Contents Size (Byte)
    Year(YYYY) 2Byte
    Month/day(MMDD) 2Byte
    Hour(HH) 2Byte
    Sampling frequency[kHz] 2Byte
    Data length for FFT[point] 2Byte
    Number of frequency channel 2Byte
    Block size [Byte] 2Byte
    Frequencies recorded 2Byte x Number of frequency channel
  • Data block format
    Contents Size (Byte)
    Start mark (0xFFFF) signed single (2Byte)
    Time (mmss) signed single (2Byte)
    Amplitude x NF @ HHmmss.0 signed single (2byte) x NF
    Phasex x NF @ HHmmss.0 signed single (2byte) x NF
    Amplitude x NF @ HHmmss.1 signed single (2byte) x NF
    Phase x NF @ HHmmss.1 signed single (2byte) x NF
    ・・・
    Amplitude x NF @ HHmmss.9 signed single (2byte) x NF
    Phase x NF @ HHmmss.9 signed single (2byte) x NF
  • NF : Number of frequency channel
  • Data conversion factors
    • Amplitude x 0.01 to convert dB
    • Phase x 0.001 to convert radian

Time averaged spectrum

  • File name: RRRYYYYMMDD.spc (RRR: station name)
  • Format: binary format
  • Time resolution : (n_save_t) sec
  • Structure of the data
    block contents
    1st block header block (header block size is the same as data block size)
    2nd block data block1 : averaged spectra at t=dt
    3rd block data block2 : averaged spectra at t=dt*2
    …
    k-th block data block(k+1): averaged spectra at t=dt*(k+1)
  • Size of each block : [n_fft / n_save_f / 2 + 1 ] x 4 Byte
  • Header block format
    Contents Size (Byte)
    Year(YYYY) 2Byte
    Month/day(MMDD) 2Byte
    Hour(HH) 2Byte
    Sampling frequency[kHz] 2Byte
    Data length for FFT[point] 2Byte
    Average time [sec] (n_save_t] 2Byte
    Number of average point in freq. [point](n_save_f) 2Byte
    Number of freq ch. saved [point] 2Byte
    Frequency resolution[Hz] 2Byte
    Block size[Byte] 2Byte
  • Data block format
    Contents Size (Byte)
    Start mark (0xFFFF) signed single (2Byte)
    Time (mmss) signed single (2Byte)
    Amplitude x NS signed single (2byte) x NS
    Phase x NS signed single (2byte) x NS
  • NS : Number of frequency channel saved
  • Data conversion factors
    • Data conversion factors
    • Phase x 0.001 to convert radian