PDS_VERSION_ID     = PDS3
RECORD_TYPE        = STREAM
OBJECT             = TEXT
  PUBLICATION_DATE = 2016-05-16
  NOTE             = "VPDS_HIGH_WINDS_FORMAT document
                      in the Viking Lander 2 seismology experiment archive."
END_OBJECT         = TEXT
END

VPDS HIGH WIND FORMAT

The data file HIGH_WIND_SUMMARY.TAB is a summary of the Viking Seismometer data
High rate records, intended as a high-level index to events of interest, and for
large-scale correlation with meteorological data.

The file was generated by parsing the raw ('VUSA') files, and where the High
mode flag was detected and valid data found, the three-axis record (83 lines
long) is summarized into a single record (one line) in the summary file. The
location (file, line number) of the original data in the VUSA file is indicated
in the summary to allow it to serve as an index – the raw data for events of
interest can therefore be easily located. Additionally a new record number is
provided in the first column, which gives the line in the reformatted raw high
rate record. The reconstructed sol, hour, minute and second are provided, as
well as the original record length. The data in the record are examined and
several parameters of interest are extracted and listed in the summary.

The four decimal parameters that follow are the moments of the 83-point X-axis
seismic record, namely the mean value, the variance, skew and kurtosis. Where
the latter two moments are undefined, a dummy value of -99 is inserted. There
then follows the integer minimum and maximum X-axis values in the record.  The
full X-axis record will be found in the corresponding line (1st column record
number) in the file VPDS_HIGH_XAMP.CSV.

The minimum and maximum values in the y axis follow, then minimum and maximum
values in the z axis. (Again, the 83 raw readings form a single line in the
files VPDS_HIGH_YAMP.CSV and VPDS_HIGH_ZAMP.CSV).

To these summary parameters are appended a time in decimal sols, and
corresponding to the nearest Viking meteorology measurements, processed by J.
Murphy. Readings of wind speed, pressure, wind direction and air temperature are
reported, as close as possible in time to the start of the seismometer
acquisition. When not simultaneous, the time from the nearest available
meteorology measurement is noted in the final column.

Original VUSA files are archived at JAXA.

The data file was generated by R. Lorenz on 12/12/2016 and may be cited 
by 'R. D. Lorenz, Y. Nakamura, J. Murphy, Viking Seismometer Data Restoration 
and Meteorological Application, VL2-M-SEIS-5-RDR-V1.0, Planetary Data System, 
2016'. This work was supported by the NASA Mars Data Analysis Program (MDAP) 
Grant, Viking Lander Meteorology and Seismology, NNX12AJ47G.

Column  1
An ordinal number indicating the record in the present file.

Column 2 
The time in decimal sols indicating the time of seismic data
acquisition (i.e. sol+(hr*3600.0+min*60.0+sec)/88775.24).

Column 3 
The file number of the original data  (i.e. file number 0101 corresponds 
to VUSA.0101.TXT).

Column 4
The line number in the VUSA file to which the present record corresponds.

Column 5
The sol number of the mission on which the data were acquired.

Column 6 
The hour of acquisition start.

Column 7
The minute of acquisition start.

Column 8
The second of acquisition start. Note that High rate data are acquired at 
20.2 Hz, thus the 83-sample record corresponds to about 4 seconds.

Column 9
The mean of the X-axis readings.

Column 10
The variance of the X-axis readings.

Column 11
The skew of the X-axis readings (or -99.99 if undefined).

Column 12
The kurtosis of the X-axis readings (or -99.99 if undefined).

Column 13
The minimum X-axis reading in the record.

Column 14
The maximum X-axis reading in the record.

Column 15
The minimum Y-axis reading in the record.

Column 16
The maximum Y-axis reading in the record.

Column 17
The minimum Z-axis reading in the record.

Column 18
The maximum Z-axis reading in the record.

Column 19
The mission time in decimal Sols  
(i.e. sol+(hr*3600.0+min*60.0+sec)/88775.24) corresponding to the 
following meteorological measurement

Column 20
Windspeed (m/s).

Column 21
 Pressure (mbar).

Column 22
Wind Direction (deg clockwise from North).

Column 23 
Air temperature (K). Note that this value has not been 
screened for possible lander thermal contamination  (see Hess et al.
1977).

Column 24 
Time in seconds between closest wind measurement and the start of the 
seismic record. A positive value denotes that the meteorological data 
were acquired before the seismic data. 

This description was generated by R. Lorenz on 12/12/2016.