org.lcsim.recon.tracking.digitization.sisim

Class DigitalReadoutChip

java.lang.Object

org.lcsim.recon.tracking.digitization.sisim.DigitalReadoutChip

All Implemented Interfaces:

ReadoutChip

public class DigitalReadoutChip
extends Object
implements ReadoutChip

Digital readout chip class. This class supports the minimal functions expected of a digital readout chip. The charge on a strip/pixel is digitized to give a specified ADC value if the charge is above the noise threshold. Noise is added to strips/pixels with charge, and random noise hits are generated as well. Methods are provided to decode the charge and time (although the current implementation always returns a time of 0).

Author:

Richard Partridge

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private class	DigitalReadoutChip.DigitalChannel DigitalChannel class representing a single channel's behavior

Nested classes/interfaces inherited from interface org.lcsim.recon.tracking.digitization.sisim.ReadoutChip

ReadoutChip.ReadoutChannel

Field Summary

Fields

Modifier and Type	Field and Description
private static org.apache.commons.math.distribution.BinomialDistribution	_binomial
private DigitalReadoutChip.DigitalChannel	_channel
private static org.apache.commons.math.distribution.NormalDistribution	_gaussian
private double	_neighbor_threshold
private double	_noise_threshold
private static Random	_random

Constructor Summary

Constructors

Constructor and Description
DigitalReadoutChip() Creates a new instance of DigitalReadoutChip

Method Summary

Methods

Modifier and Type	Method and Description
private void	addNoise(SiElectrodeDataCollection data, SiSensorElectrodes electrodes) Add noise hits for this readout chip
double	decodeCharge(RawTrackerHit hit) Decode the hit charge stored in the RawTrackerHit.
int	decodeTime(RawTrackerHit hit) Decode the hit time.
private SortedMap<Integer,List<Integer>>	digitize(SiElectrodeDataCollection data, SiSensorElectrodes electrodes) Digitizes the hit channels in a SiElectrodeDataCollection.
static int	drawBinomial(int ntrials, double probability)
static double	drawGaussianAboveThreshold(double prob_above_threshold) Return a random variable following normal distribution, but beyond threshold provided during initialization.
DigitalReadoutChip.DigitalChannel	getChannel(int channel_number) Return the DigitalChannel associated with a given channel number.
SortedMap<Integer,List<Integer>>	readout(SiElectrodeDataCollection data, SiSensorElectrodes electrodes) Given a collection of electrode data (i.e., charge on strips/pixels), return a map associating the channel and it's list of raw data.
void	setConversionConstant(int adc_for_hit) Set the ADC output value for a hit.
void	setNeighborThreshold(double neighbor_threshold) Set the threshold for reading a channel if it's neighbor is above the noise threshold.
void	setNoiseIntercept(double noise_intercept) Set the noise intercept (i.e., the noise for 0 strip/pixel capacitance).
void	setNoiseSlope(double noise_slope) Set the noise slope (i.e., the proportionality between noise and capacitance).
void	setNoiseThreshold(double noise_threshold) Set the threshold for reading out a channel.

Methods inherited from class java.lang.Object

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

Field Detail

_random

private static Random _random

_gaussian

private static org.apache.commons.math.distribution.NormalDistribution _gaussian

_binomial

private static org.apache.commons.math.distribution.BinomialDistribution _binomial

_noise_threshold

private double _noise_threshold

_neighbor_threshold

private double _neighbor_threshold

_channel

private DigitalReadoutChip.DigitalChannel _channel

Constructor Detail

DigitalReadoutChip

public DigitalReadoutChip()

Creates a new instance of DigitalReadoutChip

Method Detail

setNoiseIntercept

public void setNoiseIntercept(double noise_intercept)

Set the noise intercept (i.e., the noise for 0 strip/pixel capacitance). Units are electrons of noise.

Parameters:

noise_intercept - noise for 0 capacitance

setNoiseSlope

public void setNoiseSlope(double noise_slope)

Set the noise slope (i.e., the proportionality between noise and capacitance). Units are electrons of noise per fF of capacitance.

Parameters:

noise_slope - noise slope per unit capacitance

setNoiseThreshold

public void setNoiseThreshold(double noise_threshold)

Set the threshold for reading out a channel. Units are electrons.

Parameters:

noise_threshold -

setNeighborThreshold

public void setNeighborThreshold(double neighbor_threshold)

Set the threshold for reading a channel if it's neighbor is above the noise threshold. Units are electrons.

Parameters:

neighbor_threshold -

setConversionConstant

public void setConversionConstant(int adc_for_hit)

Set the ADC output value for a hit.

Parameters:

adc_for_hit -

getChannel

public DigitalReadoutChip.DigitalChannel getChannel(int channel_number)

Return the DigitalChannel associated with a given channel number. For the digital readout, there is a single instance of DigitalChannel and thus the channel number is ignored.

Specified by:

getChannel in interface ReadoutChip

Parameters:

channel_number - channel number

Returns:

associated DigitalChannel

readout

public SortedMap<Integer,List<Integer>> readout(SiElectrodeDataCollection data,
                                       SiSensorElectrodes electrodes)

Given a collection of electrode data (i.e., charge on strips/pixels), return a map associating the channel and it's list of raw data.

Specified by:

readout in interface ReadoutChip

Parameters:

data - electrode data from the charge distribution

electrodes - strip or pixel electrodes

Returns:

map containing the ADC counts for this sensor

decodeCharge

public double decodeCharge(RawTrackerHit hit)

Decode the hit charge stored in the RawTrackerHit. Since this method isn't well defined for digital readout, return the noise threshold if there is a hit.

Specified by:

decodeCharge in interface ReadoutChip

Parameters:

hit - raw hit

Returns:

hit pseudo-charge in units of electrons

decodeTime

public int decodeTime(RawTrackerHit hit)

Decode the hit time. Currently, the digital readout chip ignores the hit time and returns 0.

Specified by:

decodeTime in interface ReadoutChip

Parameters:

hit - raw hit data

Returns:

hit time

digitize

private SortedMap<Integer,List<Integer>> digitize(SiElectrodeDataCollection data,
                                        SiSensorElectrodes electrodes)

Digitizes the hit channels in a SiElectrodeDataCollection. The SiElectrodeDataCollection is a map that associates a given channel with it's SiElectrodeData. The SiElectrodeData encapsulates the deposited charge on an strip/pixel and any associated SimTrackerHits. The output of this class is a map that associates a channel number with a list of raw data

Parameters:

data - electrode data collection

Returns:

map associating channels with a list of raw data

addNoise

private void addNoise(SiElectrodeDataCollection data,
            SiSensorElectrodes electrodes)

Add noise hits for this readout chip

Parameters:

data - electrode data collection

electrodes - strip or pixel electrodes

drawBinomial

public static int drawBinomial(int ntrials,
               double probability)

drawGaussianAboveThreshold

public static double drawGaussianAboveThreshold(double prob_above_threshold)

Return a random variable following normal distribution, but beyond threshold provided during initialization.

Parameters:

prob_above_threshold -

Returns: