Index of /data/reports/2005/05-006
NOTES ON XINJIANG (CHINA) TEST SITES NUCLEAR EXPLOSIONS (BLACKNEST)
Version Date - 17th November 2004
The file README contains this script and other relevant notes.
The file BKNAS contains the definition of the BKNAS header and the
description of the various fields within the header.
The file LIST contains all the information required to organise,
process, and digest Chinese nuclear explosions.
The file LINKS contains links to generalise the naming of the
nuclear explosion directories.
Each year directory contains the files to process and beam-form the
seismic data for each Chinese nuclear explosion that one or more
Each directory (Site_Date.Time) contains up to five sorts of files : -
(a) Original data defined (Date.Time_STN) by the name of the file
and converted data in BKNAS, CSS, and IMS formats,
(b) Controlling files defined by date containing all necessary
information for beam-forming by the APPLE program,
(c) Phase files defined by the phase code @ the station containing
enough information for beam-forming by the APPLE program,
(d) PostScript files (I1_....ps,P1_....ps) containing information
and the seismogram plot (output from the APPLE program),
(e) Four files (info,info.all,plot,file) which contain further
Each controlling file (e.g. date_stn.input) and each phase file
(e.g. P@STN.input, PcP@STN.input, etc.) contains up to 10 lines : -
(1) The word APPLE and the sampling rate,
(2) A title most of which is self-explanatory,
(3) A number in col.1 which defines the form of the hypocentre,
(4) The hypocentre information,
(5) The station code (YKA,WRA,EKA,GBA), the sensitivity number,
and the form number for the PostScript files,
(6) The channel definition and position in the data file*,
(7) The instrument number (Blacknest code),
(8) Tape form number (20,21,32), number of channels, start time,
and other 'useful' numbers,
(+) Onset time (UTC) corresponding to start time (if known);
critical for original analogue data, optional for digital data,
(9) The name of the file of the original data.
Zero length controlling files indicate no data is available or is not
included. Phase files which are not present indicate that either
no data is available or considered not worth processing.
Of the four further information files (info,info.all,plot,file) the
most useful is info which contains a summary for each explosion.
The fields are; station code (YKA,WRA,EKA,GBA), date, start sample
(start time * sampling rate), onset time type, picked onset time,
phase, depth, distance, given Mb, amplitude, period, distance
factor, estimated magnitude Mb, maximum-likelihood magnitude M*,
and magnitude difference.
* Channel definition and position requires further explanation : -
(f) Each channel is defined by four characters and its position
in the line corresponds to its position in the data file,
(g) The first three characters define the pit code,
(h) The fourth character defines its use : -
blank for normal use,
* display but do not use,
! glitches occur but outside arrival time window +/- 5s (say),
+ use irrespective of glitches, etc.,
- invert and use irrespective of glitches, etc.,
(j) All four characters as **** indicate an unknown, a non-SP,
a grossly over-loaded, or a blank channel,
(k) On original analogue data (tape form 21) the time channel is
usually the next channel after the last defined channel and is
Suggested Processing : -
(A) Select the nuclear explosion of interest,
(B) View the selected P1_....ps file with a PostScript reader,
(C) Get the start sample number from the info file,
(D) Use appropriate tools to form a window and beam-form the event.
YKA (YELLOWKNIFE ARRAY) SPECIFIC NOTES
For this explosion the recording heads on the analogue tape deck
were not aligned correctly. The APPLE program allows for this
'skewness' so correctly beamed seismograms are generated.
For completeness, the original seismogram has been corrected and
stored as BKNAS, CSS, and IMS format files. The original raw data
file is also included.