wiki:ShmDocDatabaseSfdbQualtab

Version 1 (modified by MarcusWalther, 14 years ago) (diff)

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sfdb Table qualtab

qualref INTEGER,
gapcount INTEGER,
jitters INTEGER,
gapsize FLOAT,
offset FLOAT,
qual1 FLOAT,
qual2 FLOAT,
qual3 FLOAT,
qual4 FLOAT,
qual5 FLOAT,
qual6 FLOAT,
qual7 FLOAT,
qual8 FLOAT,
qual9 FLOAT,
version INTEGER,
PRIMARY KEY(qualref) 

Description:

  • qualref: ID number of qualtab entry. Used also in table sftab.
  • gapcount: Number of gaps found in data file, i.e. subsequent SEED records discontinuous in time. Gaps counted are larger than dt/2 (dt = sample distance).
  • jitters: Number of small data gaps in the file with length smaller than dt/2.
  • gapsize: Relative length of gaps in relation to the length of the file, i.e. total sum of the length of all data gaps divided by the time span of the file multiplied by 100.
  • offset: Offset of trace including gain. The trace is read in (using SeismicHandler, SH), the total gain is multiplied to the sample values and then the mean value of the trace is computed and stored in this entry.
  • qual1 - qual9: general quality numbers, meaning of the numbers depends on the version.
  • version: Version number defining the meaning of numbers qual1 to qual9.

In version 1 the meaning of the quality numbers is:

  • qual1: Value of amplitude spectrum of trace at 0.01 Hz (100 s).
  • qual2: Value of amplitude spectrum of trace at 0.05 Hz (20 s).
  • qual3: Value of amplitude spectrum of trace at 0.16667 Hz (6 s).
  • qual4: Value of amplitude spectrum of trace at 1.0 Hz.
  • qual5: Value of amplitude spectrum of trace at 3.5 Hz.
  • qual6: Root mean square of sample differences.
  • qual7: Not used.
  • qual8: Not used.
  • qual9: Not used.

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