glitchMon : Look for transient signals in selected channels


glitchMon is a DMT monitor which detects burst type transient signals when the amplitude of those signals exceed given thresholds.

Usage:
> glitchMon <config file>


Output:
glitchMon can output configuration summary, periodical log, raw data, trigger to the meta databse, time series and histograms for DMT Viewer and minute trend of event rates.

Output Type
Format
Description
Configuration Summary HTML
Table of the current configuration. It is written in the directory where the enviromental variable $DMTHTMLOUT points to.
Log HTML
The Log file contains a table of channel statistics for all selected channels. Each line of the table shows mean, standard deviation, number of events and length of processed data. Log files are created in the directory to where $DMTHTMLOUT points every LOGINTERVAL seconds in the configuration file.
Raw data XML (LIGO_LW)
The raw data file contains event information such as the channel name, time stamp and amplitude in the LIGO_LW format which is readable by the Event Analysis Tool. The file is created every configured interval in the user specified location by DATAPATH.
Trigger GDS_TRIGGER
Every event information can be send to the meta database by enabling the trigger option in the configuration.
Time series and histograms DMT Viewer
Time series of event rate and histogram of event size viewable on the DMT Viewer. The time series contains a history of 4 to 24-hour long minute trend of event rate. Histograms show last 24 and 2-hour statistics of the event size scaled by the sigma.
Trend FRAME
glitchMon automatically creates minute trend of event rate and stored in the directory to where $DMTRENDOUT points.


Configuration:
A configuration file consists of 5 categories of settings; monitor, threshold, filter, event parameter and channel configurations. Tags are case insensitive.

Example (3 channels with 5 cofigurations) :
	# Global monitor setting
	MONITOR {
		NAME glitchMon_Example
		SITE LLO
		DATAPATH /export/home/mito
		DURATION 0
		LOG ON
		LOGINTERVAL 60
		TRIGGER OFF
		TREND ON
		TSINTERVAL 720
	}

	# Threshold sets
	THRESHOLD { NAME th-PEM_SEIS TYPE Relative LOW 5.0 HIGH 7.0 }
	THRESHOLD { NAME th-LVEA_MAG1X TYPE Absolute LOW 1400.0 HIGH 1400.0 }
	THRESHOLD { NAME th-LSC TYPE Relative LOW 5.0 HIGH 7.0 }

	# Filter sets
	FILTER { NAME hp5 "ellip('HighPass',4,0.5,30,5)" }
	FILTER { NAME hp30 "cheby1('HighPass',4,0.5,30)" }
	FILTER { NAME hp30_lpef "cheby1('HighPass',4,0.5,30)" LPEFLENGTH 1024 LPEFTRAINPERIOD 0 LPEFTRAINLENGTH 16384 }

	# Event parameter sets
	PARAMETER { NAME param1 MINSEPARATION 1.0 MINDURATION 0.25 MAXDURATION 300.0 MINDENSITY 0.1 }
	PARAMETER { NAME param2 MINSEPARATION 2.0 MINDURATION 0.5 MAXDURATION 600.0 MINDENSITY 0.5 }

	# Histogram parameter sets
	HISTOGRAM { NAME hist50 BIN 100 LOW 0.0 HIGH 50.0 }
	HISTOGRAM { NAME hist100 BIN 200 LOW 0.0 HIGH 100.0 }

	# Channel configurations
	CHANNEL { NAME L0:PEM-LVEA_SEISX CHECKLOCK OFF
		CONFIG { THRESHOLD th-PEM_SEIS FILTER hp5 PARAMETER param1 HISTOGRAM hist50 }
	}
	CHANNEL { NAME L0:PEM-LVEA_MAG1X CHECKLOCK OFF
		CONFIG { THRESHOLD th-LVEA_MAG1X PARAMETER param1 COMMENT LLO-Magnetometer HISTOGRAM hist50 }
	}
	CHANNEL { NAME L1:LSC-AS_Q CHECKLOCK L1
		CONFIG { THRESHOLD th-LSC FILTER hp5 PARAMETER param2 HISTOGRAM hist100 }
		CONFIG { THRESHOLD th-LSC FILTER hp30 PARAMETER param1 HISTOGRAM hist100 }
		CONFIG { THRESHOLD th-LSC FILTER hp30_lpef PARAMETER param1 HISTOGRAM hist100 }
	}
	
Global Tag:
Tag Description
Monitor Global monitor settings.
Threshold A set of threshold setting. Absolute or relative threshold.
Filter A set of filter setting. IIR butterworth filter.
Parameter A set of event parameters.
Histogram A set of histogram parameters for the DMT Viewer output.
Channel A set of channel configurattion.


Monitor
:
Tag
Description
Name
Name of the monitor.
Site
Site Name. LHO or LLO
DataPath
The directory of raw data files. If not given, no raw data file is written.
Duration Monitor duration in minutes. 0 for no limit.
Log ON/OFF. Enable/Disable log output. Log files are created at $DMTHTMLOUT.
LogInterval
Update interval of the log in minutes.
Trigger ON/OFF. ON for sending trigger to the trigger manager.
Trend ON/OFF. ON for creating minute trend files in $DMTRENDOUT.
TSInterval Time length of time series output for DMT Viewer. 240 to 720 (min)


Threshold:
Tag Description
Name
Name of the threshold setting.
Type
Relative or Absolute. Relative threshold is based on the std. dev. of the channel. Absolute is based on the count.
Low
number of sigma or counts.
High
number of sigma or counts.


Filter :
Tag Description
Name
Name of the filter setting.
Formula
Filter formula. ( see FilterDesign class documentation for details. )
LPEFLength Liner Predictive filter length*
LPEFTrainPeriod Liner Predictive filter re-training interval*
LPEFTrainLength Liner Predictive training length*

*The resulting data stream will be uncorrelated ("white") on lengths less than LPEFLength. The LPEFTrainPeriod argument is not currently used and should be set to zero. The filter is automatically retrained once every second. The maximum allowable LPEFTrainLength is equal to the sample frequency, since no more than one second of data is available for training. See the LPEFilter class documentation for more details. The LPEFilter is applied after the other filter has been applied.

Parameter
:
Tag Description
Name
Name of the parameter set.
MinSeparation
Minimum event separation (sec) for the consecutive events. Events separated by less than this time interval are combined into one single event.
MinDuration
Minimum duration of an event.
MaxDuration
Maximum duration of an event.
MinDensity
Minimum portion of the data point greater than (Low) threshold in an event.


Histogram :

Tag Description
Name Name of the histogram parameters.
Bin Number of bins.
Low Lower edge.
High Upper edge.


Channel
:
Tag Description
Name
Name of the channel
CheckLock
OFF, H1, H2 or L1. Search for the events only if the given IFO is locked.
Config
Choose a theshold, filter and parameter from each list and make a set of configuration. A Channel can hold multiple Configs.
Tag Description
Threshold Name of a threshold set.
Filter Name of a filter set.
Parameter Name of a parameter set.
Comment
(optional) A comment fot this configuration. Used for the trigger sub ID. If not specified, the sub ID is automatically created based on the channel name, threshold and filter setting.

 
Algorithm :

The following figure is an example of a transient event. Red lines shows threshold level. glitchMon searches the initial and final time of the transient exceeding the threshold level specified by the "Low" tag in the threshold setting.

To determine the event to be triggered, the event information is comapred to the threshold and parameter set. There are two categories of trigger conditions based on the size of the event.

Trigger condition for dmtviewer : ( Triggered if following three conditions are fulfilled )
Event rate and amplitude histograms are updated. No event information is sent to Meta DB. Trigger condition for the Meta Database : ( Triggered if following three conditions are fulfilled )
Event rate and amplitude histograms are updated, and also event information is sent to Meta DB. If Low threshold less than or equal to the High threshold, all triggers are sent to the Meta DB.
if High threshold is zero, no events is sent to the Meta DB.

GDS_TRIGGER entries :
GDS_TRIGGER tag Description
IFO IFO identifier (H0, H1, H2, L0 or L1)
NAME Name of the monitor as cofigured in the configuration file
SUBTYPE Channel name + threshold and filter information
START_TIME, START_TIME_NS Event start time
FREQUENCY Time at the max amplitude of the event
BANDWIDTH Number of data points exceeding the LOW threshold
SIZE Maximum amplitude in sigma
SIGNIFICANCE Size of the standard deviation of the channel in ADC count
glitch_pic.jpg


Author : Masahiro Ito
E-mail : masahiro@darkwign.uoregon.edu