• Antelope Release 5.10 Linux CentOS release 7.6.1810 (Core) 3.10.0 2020-05-12

 

NAME

dbdetect - multi-frequency STA/LTA detector

SYNOPSIS


dbdetect [-v] [-arrivals] [-noaddchk]
         [-tstart start_time] [-twin minutes]
         [-onlypicks] [-pf pfname] dbin dbout

DESCRIPTION

dbdetect will read waveform data from an input Datascope database, run STA/LTA detectors on one or more channels of the waveform data and write the detection states as detection and optionally arrival rows into an output Datascope database. For each channel of data, dbdetect will prefilter the data into a specified frequency pass band. dbdetect can run multiple detections on the same channel of data with different frequency pass bands. This program is similar to orbdetect(1) except that it takes its input and puts its output into Datascope databases instead of ORBs.

OPTIONS

PROGRAM PARAMETER FILE

Following is an example dbdetect parameter file.

#	Parameter file for dbdetect

#	Following are required and are used as overall defaults

ave_type	rms	# Method for averaging (rms or filter)
sta_twin        1.0	# short term average time window
sta_tmin        1.0	# short term average minimum time for average
sta_maxtgap     0.5	# short term average maximum time gap
lta_twin        10.0	# long term average time window
lta_tmin        5.0	# long term average minimum time for average
lta_maxtgap     4.0	# long term average maximum time gap
nodet_twin	2.0	# no detection if on time is less than this
pamp            500.0	# plot amplitude
thresh		5.0	# detection SNR threshold
threshoff	2.5	# detection-off SNR threshold
det_tmin	20.0	# detection minimum on time
det_tmax	600.0	# detection maximum on time
h		0	# plot channel height in pixels
filter		none	# default filter
iphase		D	# default iphase for detections
otime_noise_tfac 1.0	# ratio of noise tapering time constant to
			#  signal tapering time constant for onset
			#  time estimation

process_twin	60.0	# data is processed in hunks of this duration
onset_search_offset -1.0 # time offset in front of detection to look for onset

#	At least one default band must be set set up in the bands table
#	parameter values override default values above for each band

bands	&Tbl{
	&Arr{
		sta_twin        5.0
		sta_tmin	5.0
		sta_maxtgap	0.5
		lta_twin        50.0
		lta_tmin	25.0
		lta_maxtgap	4.0
		pamp		200.0
		filter		BW 0.5 4 1.2 4
	}
	&Arr{
		sta_twin        2.0
		sta_tmin	2.0
		sta_maxtgap     0.5
		lta_twin        20.0
		lta_tmin	10.0
		lta_maxtgap     4.0
		pamp		500.0
		filter		BW 0.8 4 3.0 4
	}
	&Arr{
		sta_twin        1.0
		sta_tmin	1.0
		sta_maxtgap     0.5
		lta_twin        10.0
		lta_tmin	5.0
		lta_maxtgap     4.0
		pamp		500.0
		filter		BW 3.0 4 0 0
	}
}

#	At least one data channel must be specified in the stachans table

stachans	&Tbl{
# 	sta	chan
	.*	[SB]HZ|BHZ_..
}

#	station/channels to reject in the processing
reject &Tbl{
# 	sta	chan
# 	ABC	BHZ
}

#	Individual netstachan parameters may be overriden below - following
#	entries are optional
PFO/BHZ	&Arr{
	bands	&Tbl{
		&Arr{
			sta_twin        5.0
			sta_tmin	5.0
			sta_maxtgap	0.5
			lta_twin        50.0
			lta_tmin	25.0
			lta_maxtgap	4.0
			pamp		200.0
			filter		BW 0.5 4 1.2 4
		}
		&Arr{
			sta_twin        2.0
			sta_tmin	2.0
			sta_maxtgap     0.5
			lta_twin        20.0
			lta_tmin	10.0
			lta_maxtgap     4.0
			pamp		500.0
			filter		BW 0.8 4 3.0 4
		}
		&Arr{
			sta_twin        1.0
			sta_tmin	1.0
			sta_maxtgap     0.5
			lta_twin        10.0
			lta_tmin	5.0
			lta_maxtgap     4.0
			pamp		500.0
			filter		BW 3.0 4 0 0
		}
	}
	h       50
}

The parameter file consists of three sections followed by optional override sections. In the first section all of the default parameters must be specified. These default parameters are as follows:

The second section specifies the default frequency bands that will be used for each channel. This section must contain a table named "bands". Within this table is one or more arrays that contain overridden parameter values for each of the frequency bands to be used. The parameter definitions are the same as for those of the default parameters section (the first section). Each frequency band has its own set of parameters that are initialized from the default parameters. The specifications in the "bands" table overrides the default parameter values.

The third section contains the list of CSS3.0 station channel codes, in a table named "stachans", that define the data channels to be processed. You can use regular expressions in this table which will be compared against incoming CSS3.0 station and channel codes to determine whether or not to process the channel. The station and channel codes (or regular expressions) must be separated by white space. In addition to the "stachans" table, an optional "reject" table may also be specified. This is in the same form as the "stachans" table and specifies channels the will not be processed.

One or more optional arrays can be specified that further override detection parameters for particular CSS3.0 sta/chan codes. The names of each array should be the sta/chan code and the values can be anything in the first two sections that specify the default and band parameters.

SEE ALSO


orbdetect(1)

AUTHOR

Danny Harvey
Boulder Real Time Technologies, Inc.
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