stella.parameter
Class Efficiency

java.lang.Object
  util.PropertyContainer
      util.PropertyResources
          util.PropertyBundles
              stella.parameter.AbstractParameter
                  stella.parameter.AbstractRemoteParameter
                      stella.parameter.AbstractFitsParameter
                          stella.parameter.AbstractFitsValue
                              stella.parameter.Efficiency

All Implemented Interfaces:

Cloneable, Remote, EventListener, EventTrigger, Parameter, ParameterDepending, RemoteFitsParameter, RemoteParameter, Value, ExitCleaning, Initializable, LocalizedSupplying, PropertySupplying, Reloadable, ResourceSupplying, RmiCaster

public class Efficiency
extends AbstractFitsValue
implements ParameterDepending, Reloadable

This class takes a fits file, extracts a region around AbstractFitsValue.KEY_WINDOW, determines the total flux there and relates it to the incident flux of the star on top of the atmosphere.

The flux is determined in the following way:

• The counts in the extracted windows are sorted.
• The median value is the upper limit of interorder pixel, background is estimated as the median of these interorder pixels. This means implementation wise, the central count value of the sorted array defines the median, then increse the index until a count higher than this value is encountered. The background is now the the value at half the remaining index.
• Subtract background and sum box.
• Calculate total electron flux by multiplying with gain KEY_GAIN and devide by exposure time. A quantum efficiency of 100% means this is also the photon flux.
• Get flux per Angstrom by deviding the flux with height of window times KEY_ANGSTROMPIXEL.
• Relate that to the incident flux of the star, roughly given as KEY_R0FLUX 10^-0.4*R_mag[photons/sec/A].

Note that an R=0 star has ~1.07*10^10 photons/m2/sec. magnitude

Nested Class Summary

static class

Efficiency.File Test class and class for processing fits files in-situ.

Nested classes/interfaces inherited from class stella.parameter.AbstractFitsValue

AbstractFitsValue.Extract

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.URLResource

Field Summary

private static double	DEFANGSTROMPIXEL Default Angstrom per pixel at window.
private static double	DEFGAIN Default gain.
private static double	DEFHIGHSIGNAL
static String	DEFNAME Name of this parameter.
private static double	DEFR0FLUX Photon flux per Angstrom around 6500, for 1.2m telescope.
private static double	DEFREADNOISE Default readnoise.
static String	KEY_ANGSTROMPIXEL Angstrom per pixel at the center of the extracted region.
static String	KEY_GAIN Gain of the SES CCD.
static String	KEY_HIGHSIGNAL Multiplier to get from statistic sigma to upper-limit bound.
static String	KEY_R0FLUX Photon flux of R=0.0 star for STELLA M1 size above atmosphere.
static String	KEY_READNOISE Estimate of the read-noise of the CCD, just for histogram bins.
static String	KEY_RMAG Name of the rmag parameter.
private Value	rmag The rmag of the target, set remotely.

Fields inherited from class stella.parameter.AbstractFitsValue

KEY_WINDOW

Fields inherited from class stella.parameter.AbstractRemoteParameter

DEFBIND, KEY_BIND

Fields inherited from class stella.parameter.AbstractParameter

KEY_FORMAT, KEY_NAME, KEY_PRESERVE, UNKNOWN

Fields inherited from class util.PropertyBundles

KEY_LOCALECOUNTRY, KEY_LOCALELANGUAGE, KEY_RESOURCEBUNDLES

Fields inherited from class util.PropertyResources

KEY_NOINITONCREATE, localurl, locate, POSTFIX_DIR, POSTFIX_EXT, POSTFIX_FILE, POSTFIX_LIST, POSTFIX_URL, urlset

Fields inherited from class util.PropertyContainer

KEY_LISTSEPARATOR, KEY_MAPKEYVALUECHAR, KEY_MAPSEPARATOR

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Fields inherited from interface util.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Constructor Summary

Efficiency(Map<String,String> prop)
Constructs a new efficiency measuring tool.

Method Summary

private Double	estimateEfficiency(List<Double> adus, double exptime, float rmag) Provide a fits file, an exposure time in seconds and an R-magnitude of the object and determine the fraction of photons detected.
Number	getValue() Returns the efficiency measure as a Double value.
void	registerParameter(Parameter what) Registers the RMag of the target to this parameter.
double	rescanned(String key, String old, String newval) As any parameter depending instance we fail if the parameter we depend on is now a different one.
Number	setValue(Number val) Sets the efficiency, which is a read-only variable, therefore this method throws an UnsupportedOperationException.

Methods inherited from class stella.parameter.AbstractFitsValue

get, getAdus, getMode, getSigmaFromLow, getSignal, getWindow, processFits

Methods inherited from class stella.parameter.AbstractFitsParameter

addRmiListener, getDateObs, getExposureTime, getRegistered, registerFits, registerMonitor, removeRmiListener, rmiDateObs, rmiExposureTime, rmiRegistered, set, setDateObs, setExposureTime, setRegistered

Methods inherited from class stella.parameter.AbstractRemoteParameter

bindToRegistry, exit, init, isValid, remoteGet, unbindFromRegistry

Methods inherited from class stella.parameter.AbstractParameter

createParameter, delivers, getFormatted, getFormatted, getName, getPreserveFile, getString, getString, register, setName, toString

Methods inherited from class util.PropertyBundles

clone, getLocalized, getLocalized, getLocalizedString, getLocalizedString, loadResource

Methods inherited from class util.PropertyResources

createFrom, createFrom, createFrom, getApplet, getAsResources, getLocalClassLoader, getPropertiesToKey, getPropertiesToKey, getResource, getResourceAsStream, getResourceFromKey, getResources, keyCreate, keyCreate, reload, setApplet

Methods inherited from class util.PropertyContainer

augment, augment, augment, defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsEnums, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, isNew, parseObject, reload, removeProperty, setObject, setProperties, setProperty, stringProperties

Methods inherited from class java.lang.Object

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

Methods inherited from interface util.Reloadable

reload

Methods inherited from interface stella.Parameter

getFormatted, getName, getString, set

Methods inherited from interface util.PropertySupplying

defaultBoolean, defaultChar, defaultDouble, defaultFloat, defaultInt, defaultLong, defaultObject, defaultObject, defaultProperties, defaultProperty, getAsBoolean, getAsChar, getAsDouble, getAsFloat, getAsInt, getAsList, getAsLong, getAsMap, getAsObject, getAsObject, getProperties, getProperty, has, parseObject, removeProperty, setObject, setProperty, stringProperties

Methods inherited from interface util.Initializable

init

Methods inherited from interface stella.rmi.RemoteParameter

remoteGet

Methods inherited from interface util.rmi.RmiCaster

bindToRegistry, isValid, unbindFromRegistry

Methods inherited from interface util.ResourceSupplying

getResource, getResourceAsStream, getResources

Field Detail

KEY_GAIN

public static final String KEY_GAIN

Gain of the SES CCD.

See Also:

Constant Field Values

KEY_READNOISE

public static final String KEY_READNOISE

Estimate of the read-noise of the CCD, just for histogram bins.

See Also:

Constant Field Values

KEY_ANGSTROMPIXEL

public static final String KEY_ANGSTROMPIXEL

Angstrom per pixel at the center of the extracted region.

See Also:

Constant Field Values

KEY_R0FLUX

public static final String KEY_R0FLUX

Photon flux of R=0.0 star for STELLA M1 size above atmosphere.

See Also:

Constant Field Values

KEY_RMAG

public static final String KEY_RMAG

Name of the rmag parameter.

See Also:

Constant Field Values

KEY_HIGHSIGNAL

public static final String KEY_HIGHSIGNAL

Multiplier to get from statistic sigma to upper-limit bound.

See Also:

Constant Field Values

DEFNAME

public static final String DEFNAME

Name of this parameter.

See Also:

Constant Field Values

DEFGAIN

private static final double DEFGAIN

Default gain.

See Also:

Constant Field Values

DEFREADNOISE

private static final double DEFREADNOISE

Default readnoise.

See Also:

Constant Field Values

DEFANGSTROMPIXEL

private static final double DEFANGSTROMPIXEL

Default Angstrom per pixel at window.

See Also:

Constant Field Values

DEFR0FLUX

private static final double DEFR0FLUX

Photon flux per Angstrom around 6500, for 1.2m telescope.

See Also:

Constant Field Values

DEFHIGHSIGNAL

private static final double DEFHIGHSIGNAL

See Also:

Constant Field Values

rmag

private Value rmag

The rmag of the target, set remotely.

Constructor Detail

Efficiency

public Efficiency(Map<String,String> prop)

Constructs a new efficiency measuring tool. After construct, call estimateEfficiency(java.util.List, double, float) retrieve the value.

Method Detail

rescanned

public double rescanned(String key,
                        String old,
                        String newval)

As any parameter depending instance we fail if the parameter we depend on is now a different one.

Specified by:

rescanned in interface Reloadable

Overrides:

rescanned in class AbstractFitsValue

registerParameter

public void registerParameter(Parameter what)

Registers the RMag of the target to this parameter. We only register the R-mag of the target, as the fits file should be set when it was entirely read.

Specified by:

registerParameter in interface ParameterDepending

getValue

public Number getValue()

Returns the efficiency measure as a Double value. If the rmag is missing or not set or the fits file is invalid, we return null.

Specified by:

getValue in interface Value

setValue

public Number setValue(Number val)
                throws UnsupportedOperationException

Sets the efficiency, which is a read-only variable, therefore this method throws an UnsupportedOperationException.

Specified by:

setValue in interface Value

Overrides:

setValue in class AbstractFitsValue

Throws:

UnsupportedOperationException

estimateEfficiency

private Double estimateEfficiency(List<Double> adus,
                                  double exptime,
                                  float rmag)

Provide a fits file, an exposure time in seconds and an R-magnitude of the object and determine the fraction of photons detected. If anything fails, -1 is returned.

Parameters:

adus - ADU count statistic from a representative SES area

exptime - Exposure time in seconds.

rmag - Magnitude of star in R band.