NAME

orbwfmeas - make waveform measurments from an ORB

SYNOPSIS


orbwfmeas [-select_wf expr] [-start {pktid|time|OLDEST|NEWEST}]
          [-number number] [-nowait] [-state statefile]
          [-p parameter_file] [-dbsift_expr dbsift_expr]
          {detection|arrival} orbwf orbdb dbname

DESCRIPTION

orbwfmeas is a program that continuously looks for either /db/detection or /db/arrival packets on an ORB and computes various waveform measurements whenever a packet is read. The waveform measurements are normally written back to the ORB as /db/wfmeas packets.

OPTIONS

PROGRAM PARAMETER FILE

The orbwfmeas parameter file contains information that defines the particular measurements to be made. Currently there are six recognized measurement types;

An example orbwfmeas parameter file is as follows:


#
#	orbwfmeas.pf contains the parameters for making waveform
#	measurements
#

global_defaults &Arr{
    remove_mean      yes    # Remove mean from waveform data
                            #   after filtering before making
                            #   measurements
    use_det_filter   yes    # Use filter parameters from input
                            #   detection packets instead of
                            #   from this parameter file
    latency          20.0   # Maximum allowed waveform data packet
                            #   latency in seconds. If there are
                            #   gaps in the requested waveform time
                            #   window, then will continue reading
                            #   waveform packets until the time
                            #   is greater than latency seconds
                            #   past the end of the requested time
                            #   window in order to fill the gaps.
    timeout          120.0  # Maximum wall-clock time in seconds
                            #   to wait for waveform data packets.
    ptype            single # This determoines how multi-channel
                            #   processing is done:
                            #   single  - Process and output each
                            #             channel independently
                            #   biggest - Process all channels and
                            #             output only the largest or best
                            #             value from all of the channels
                            #   vector  - Process only the absolute vector
                            #             amplitude composed from the
                            #             individual channels
    calib_from_calibration  no # Should calib values come
                               #   from the database calibration
                               #   table (yes) or directly from
                               #   the data ORB packets (no)?
}

measurements &Tbl{
    &Arr{
        type     peakd       # peak displacement measurements
        tlead    10.0        # lead time window in seconds
        tlag     10.0        # lag time window in seconds
        tpad     10.0        # time pad in seconds to remove
                             #   filter transients
        use_det_filter   yes # Use filter parameters from input
                             #   detection packets
        filter   BW 1. 5 0 0 # pre-filter, used only if use_det_filter
                             #   is set to no
        channels &Tbl{       # channels to process
        #    sta_expr    chan_expr	[wfchan_expr]
            .*           HL.
        &Arr{            # over-ride filter parameter for
                         #   sta AZ_PFO
                sta_expr       AZ_PFO
                chan_expr      .*
                filter         BW 0.1 5 0 0
        }
    }
    &Arr{
        type	peakv		# peak ground velocity measurement
        lead	10.0		# lead time window in seconds
        lag	20.0		# lag time window in seconds
        pad	10.0		# time pad in seconds to remove
                                #   filter transients
        ptype   vector
        otype    wfmgme          # write output to wfgme rows
        channels &Tbl{		# channels to process
#               sta_expr chan_expr wfchan_expr
                .*       HGZ       HG.
        }
    }
    &Arr{
        type	peaka		# peak ground acceleration measurement
        lead	10.0		# lead time window in seconds
        lag	20.0		# lag time window in seconds
        pad	10.0		# time pad in seconds to remove
                                #   filter transients
        ptype   vector
        otype    wfmgme          # write output to wfgme rows
        channels &Tbl{		# channels to process
#               sta_expr chan_expr wfchan_expr
                .*       HGZ       HG.
        }
    }
    &Arr{
        type	peakwa		# peak Wood-Anderson measurement
        lead	10.0		# lead time window in seconds
        lag	20.0		# lag time window in seconds
        pad	10.0		# time pad in seconds to remove
                                #   filter transients
        ptype   biggest
        otype    wfmgme_flush    # write output to wfgme rows and flush
        channels &Tbl{		# channels to process
#               sta_expr chan_expr wfchan_expr
                .*       HGZ       HG[NE]
        }
    }
}

The parameter file is broken into two main sections; the global_defaults array, which is used to define the values of parameters to be used as global default values, and the measurements table, which contains unnamed parameter arrays corresponding to the different measurements that are to be made. The particular measurements are made in the order in which they are specified in the measurements table. Each of the measurement arrays contain parameters for that measurement and a table of channels to be processed. Any missing parameters from a measurement array will be taken from the global defaults array. Each of the measurement arrays must contain a type parameter, which defines the measurement type, and a channels table, which lists the station-channels to be processed. Each row in the channels table must contain either a simple character string with two or three fields, the first a sta expression, the second a chan expression and the third an optional waveform chan expression, or another unnamed parameter array which must contain at least a sta_expr parameter and a chan_expr parameter. These unnamed arrays within the channels table may also contain any of the other parameters for that measurement type, and any such parameters over-ride the measurement parameters for the stations and channels that match that sta_expr and chan_expr. When input channels match more than one row in the channels table, then the last row which matches is used.

peak measurement arrays are used to set up data channels and parameters for making peak waveform amplitude measurements. The peak measurements are made in units that are natural to the data, nm/sec for velocity sensor data, milli-Gs (mg) for acceleration sensor data (where g is defined to be 9.80665 m/s^2). The sensor type is obtained either directly from the input waveform data packets or from the database, as specified through the dbname command line argument. Peak waveform measurements are made for both a time window immediately after the detection/arrival time, refered to as a signal peak value, and for a time window immediately prior to the detection/arrival time, refered to as a noise peak value. The signal peak value is written into the val1 field of the output wfmeas packet and the noise peak value is written into the val2 field. The time corresponding to the signal peak value is written into the tmeas field. The parameters for peak measurements are defined below.

peaka measurements are used to set up data channels and parameters for making peak ground acceleration measurements. The peak acceleration measurements are made in milli-Gs (mg) for all sensor types. Data from velocity sensors are automatically differentiated to convert to acceleration. All other information and processing are as for the peak measurement type. Note that instrument deconvolution is not performed here, only simple differentiation.

peakv measurements are used to set up data channels and parameters for making peak ground velocity measurements. The peak velocity measurements are made in nm/sec for all sensor types. Data from acceleration sensors are automatically integrated to convert to velocity. All other information and processing are as for the peak measurement type. Note that instrument deconvolution is not performed here, only simple integration.

peakd measurements are used to set up data channels and parameters for making peak ground displacement measurements. The peak displacement measurements are made in nm for all sensor types. Data from acceleration sensors are automatically integrated twice to convert to displacement. Data from velocity sensors are automatically integrated once to convert to displacement. All other information and processing are as for the peak measurement type. Note that instrument deconvolution is not performed here, only simple integration.

peakwa measurements are used to set up data channels and parameters for making peak equivalent Wood-Anderson measurements. The peak Wood-Anderson measurements are made in equivalent mm of Wood-Anderson drum recorder for all sensor types. Data from sensors are automatically integrated to convert to displacement and then forward filtered with a Wood-Anderson instrument filter. All other information and processing are as for the peak measurement type. Note that instrument deconvolution is not performed here, only simple integration and Wood-Anderson filtering.

AUTHOR

Danny Harvey
Boulder Real Time Technologies, Inc.

Table of Contents
Antelope Release 4.7 Linux 2.4.19-4GB 2005-12-21
Boulder Real Time Technologies, Inc For more information, contact support@brtt.com