fact.datacorrection

Class DrsTimeCalibration

java.lang.Object

fact.datacorrection.DrsTimeCalibration

All Implemented Interfaces:

stream.Processor, stream.StatefulProcessor

public class DrsTimeCalibration
extends Object
implements stream.StatefulProcessor

Applies DRS4 time calibration by using long_term_constants_median.time.drs.fits

The common reference point is the 976.5625 kHz DRS4 reference clock. This means the time of sampling physical cell zero is assumed to be equal for all 160 DRS4 chips in the camera.

After finding the corrected sampling time of each sample in 'dataKey', the data is resampled using a linearTimeCorrectionKernel, in order to obtain a time series which may be treated as if the 2GHz DRS4 sampling process was flawless.

The resampling time series starts at the maximum corrected start time of all pixels and always contains 300 samples. In case there are no more supporting points in the original time series, i.e. in case we would need to extrapolate instead of interpolate, the last sample is repeated.

This means the end of the time series is likely to contain unphysical data. Most processors disregard the end of the time series and therefor this might not matter a lot, but features like PedVar, which are extracted at random positions of the timeline should be restricted to a timeframe between sample 10 and 250 I would say.

Author:

Dominik Neise <neised@phys.ethz.ch>

Field Summary

Fields

Modifier and Type	Field and Description
String	dataKey
String	drsTimeKey
String	outputKey
String	startCellKey
URL	url

Constructor Summary

Constructors

Constructor and Description
DrsTimeCalibration()

Method Summary

Modifier and Type	Method and Description
void	finish()
void	init(stream.ProcessContext context)
protected void	loadDrsTimeCalibConstants(URL in)
stream.Data	process(stream.Data item)
void	resetState()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

startCellKey

@Parameter(required=false,
           description="Key of the StartCellData in the data fits file",
           defaultValue="StartCellData")
public String startCellKey

drsTimeKey

@Parameter(required=false,
           description="name of column in FITS file to find DRS4 time calibration constants.")
public String drsTimeKey

url

@Parameter(required=false,
           description="file with the drs time calib constants",
           defaultValue="classpath:/long_term_constants_median.time.drs.fits")
public URL url

dataKey

@Parameter(required=true,
           description="key to the drs amplitude calibrated voltage curves")
public String dataKey

outputKey

@Parameter(required=true,
           description="OutputKey for the calibrated voltage curves")
public String outputKey

Constructor Detail

DrsTimeCalibration

public DrsTimeCalibration()

Method Detail

init

public void init(stream.ProcessContext context)

Specified by:

init in interface stream.StatefulProcessor

process

public stream.Data process(stream.Data item)

Specified by:

process in interface stream.Processor

loadDrsTimeCalibConstants

protected void loadDrsTimeCalibConstants(URL in)
                                  throws IOException

Throws:

IOException

resetState

public void resetState()
                throws Exception

Specified by:

resetState in interface stream.StatefulProcessor

Throws:

Exception

finish

public void finish()
            throws Exception

Specified by:

finish in interface stream.StatefulProcessor

Throws:

Exception