stella.util
Class MomentsFocusser

java.lang.Object
  util.PropertyContainer
      util.PropertyResources
          util.PropertyBundles
              stella.util.MomentsFocusser

All Implemented Interfaces:

DriverDepending, Cloneable, ParameterDepending, Initializable, LocalizedSupplying, PropertySupplying, ResourceSupplying

public class MomentsFocusser
extends PropertyBundles
implements DriverDepending, ParameterDepending

This class uses maximization of ADU moments to obtain a best focus. Its mechanism of offsetting the focus are unspecified, but a CCD must be present in order to obtain images from which ADU statistics can be drawn. Additionally, a method must be present that allows a crude estimate of the focus position. This can be done with a temperature model, but any other mechanism is allowed, as long as it adheres to crudeFocus().

Nested Class Summary

static class

MomentsFocusser.IntExt This class takes a extra focal and an intra focal image and calculates the focus that follows from the A4 parameter.

Nested classes/interfaces inherited from class util.PropertyResources

PropertyResources.URLResource

Field Summary

private CcdDriver	ccd The CCD to take images with.
private static double	DEFA4ERROR Default A4 error (2011-10-14).
private static double	DEFA4SLOPE Default A4 slope (2011-10-14).
private static Dimension	DEFADUSIZE The default size around the bright spot.
private static Dimension	DEFBLOBSIZE The default blob size.
private static boolean	DEFDOSAVE If true we save the indivdual images during focus.
private static boolean	DEFDOSEARCH If temperature model is accurate enough, we can skip the search.
private static double	DEFERRORZERNIKE Default always do sequence.
private static double	DEFEXPOSEFOCUS The default S/N on acquire.
private static int	DEFEXTENSION The moment during fine focus.
private static Dimension	DEFFOCUSBINNING The default binning on acquire.
private static int	DEFFOCUSORDER The moment during fine focus.
private static double	DEFHIGHSKYSIGMA Per default we do not do ADU rejection, thus this is zero.
private static double	DEFLOWSKYSIGMA Per default we do not do ADU rejection, thus this is zero.
private static boolean	DEFMEDIANSKY Default we use median for sky-level determination.
private static String	DEFMOMENTS Default moments parameter name.
private static int	DEFSEARCHORDER The moment during coarse focus.
private static int	DEFSEARCHSTEPS Default half-number of search steps.
private static int	DEFSKYFRAME The defautl sky frame size.
private static String	DEFUNIQUE Default unique parameter name.
private static double	DEFZERNIKESTEP Default no extra Zernike images.
private static double	DEFZEXPOSE Default no extra increase in exposure time on Zernikes.
private long	expt The exposure time in ms calculated once per focus sequence.
static String	EXTRAFOCAL Extension for extrafocal image in Zernike coefficient determination.
static String	INTRAFOCAL Extension for intrafocal image in Zernike coefficient determination.
static String	KEY_A4ERROR This is the error estimate for A4 slope.
static String	KEY_A4SLOPE This is the slope of A4 versus steps.
static String	KEY_ADUSIZE The box to scan for A4.
static String	KEY_BLOBSIZE The default blob size.
static String	KEY_CCD The name of the ccd to use.
static String	KEY_DOSAVE Save the focus sequence images.
static String	KEY_DOSEARCH Once the temperature model is accurate enough, we do not search.
static String	KEY_ERRORZERNIKE If the zernike error is below this, we spare the sequence.
static String	KEY_EXTENSION The extension with best signal if more than one amplifier.
static String	KEY_FOCUSBINNING The binnning for focus images.
static String	KEY_FOCUSFRAME The frame for focus images.
static String	KEY_FOCUSOFFSET The offset from the optimal focus for image 1&2.
static String	KEY_FOCUSORDER The moment during fine focus.
static String	KEY_HIGHSKYSIGMA If greather than zero, the high bound sigma for background rejection.
static String	KEY_LOWSKYSIGMA If greather than zero, the low-bound sigma for background rejection.
static String	KEY_MAXFOCUSEXPOSE If the exposure time required for moments exceed this, do T only.
static String	KEY_MEDIANSKY If true, use median in background frame.
static String	KEY_MOMENTS The name of the fits moments to use.
static String	KEY_MOMENTSFRAME The frame for focus moments, smaller than image frame.
static String	KEY_SEARCHOFFSET The step with, if focus model is bad.
static String	KEY_SEARCHORDER The moment during coarse focus.
static String	KEY_SEARCHSTEPS The number of search steps in either direction.
static String	KEY_SKYFRAME The default sky frame size.
static String	KEY_STEP0 The focus position for focus temperture T0.
static String	KEY_STEPTEMP Per degree difference to T0, we add this number of steps.
static String	KEY_TEMP0 At this temperature, optimal focus is at step0.
static String	KEY_TEMPERATURE The name of the temperature to use.
static String	KEY_UNIQUE The name of the unique parameter.
static String	KEY_ZERNIKESTEP If this multiplier to searchsteps is greater 0, we do Zernikes.
static String	KEY_ZEXPOSE Multiplier to nominal exposure time for extra/intra focal Zernike.
private FitsMoments	moments The fits-moments parameter.
private Focusable	telescope The object that allows me to set the focus.
private Value	temp The value that delivers the temperature relevant for focus model.
private Parameter	unique The unique parameter.

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.ResourceSupplying

KEY_URLRESOURCES, KEY_URLUSECONFIG, KEY_URLUSECURRENT, KEY_URLUSEHOME

Fields inherited from interface util.PropertySupplying

CONFIG, KEY_CLASS

Constructor Summary

MomentsFocusser(Map<String,String> prop)
Constructor chaining.

Method Summary

private double	coarseFocus() In the coarse focus, we do a temperature model, even if very inaccurate, then procced to in and out with #KEY_SEARCH step, doing a image on the small frame along the offsets.
protected double	crudeFocus() We position the linear sledge at the temperature model focus.
ErrorEvent	doFocus() Task of this object is to auto focus after a successful acquire.
private double	doZernikes(double zernike, double pos0) Does two zernike out-of-focus image and returns true if the focus obtained is good enough.
private Double[]	getMomentAt(double step, int order, String fext) We position the linear stage at the indicated step, take an image with the CCD camera on the #KEY_FOCSUFRAME and calculate the moments of this image.
private Double	getMomentValue(CentralMoments cm, int order) Gets the requested value from our central moments.
boolean	isReady() Checks, if all required values and objects are in place, sparing expt.
boolean	isValid() Checks, if all required values and objects are in place.
boolean	registerDriver(Driver d) If this driver is a ccd and its name equals KEY_CCD.
void	registerExposureTime(long ms) The exposure time is set from the outside.
void	registerFocus(Focusable f) We register the object that can set a focus position.
void	registerParameter(Parameter p) We use the parameter, if it is a fitsmoments and if the name agrees with the property KEY_MOMENTS
private double	scanA4(nom.tam.fits.Fits ff, int use) We calculate the A4 parameter from second image moments following Equation 5 in PASP118, 1165, but without pixel scaling.
private nom.tam.fits.Fits	takeSingleImage(CcdDriver ccd, long ms, Dimension bin, String store) Takes a single image, stores it, if desired.

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, init, 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, rescanned, setObject, setProperties, setProperty, stringProperties, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface util.ResourceSupplying

getResource, getResourceAsStream, getResources

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

Field Detail

EXTRAFOCAL

public static final String EXTRAFOCAL

Extension for extrafocal image in Zernike coefficient determination.

See Also:

Constant Field Values

INTRAFOCAL

public static final String INTRAFOCAL

Extension for intrafocal image in Zernike coefficient determination.

See Also:

Constant Field Values

KEY_UNIQUE

public static final String KEY_UNIQUE

The name of the unique parameter.

See Also:

Constant Field Values

KEY_MOMENTS

public static final String KEY_MOMENTS

The name of the fits moments to use.

See Also:

Constant Field Values

KEY_TEMPERATURE

public static final String KEY_TEMPERATURE

The name of the temperature to use.

See Also:

Constant Field Values

KEY_CCD

public static final String KEY_CCD

The name of the ccd to use.

See Also:

Constant Field Values

KEY_FOCUSOFFSET

public static final String KEY_FOCUSOFFSET

The offset from the optimal focus for image 1&2.

See Also:

Constant Field Values

KEY_FOCUSORDER

public static final String KEY_FOCUSORDER

The moment during fine focus.

See Also:

Constant Field Values

KEY_EXTENSION

public static final String KEY_EXTENSION

The extension with best signal if more than one amplifier.

See Also:

Constant Field Values

KEY_SEARCHSTEPS

public static final String KEY_SEARCHSTEPS

The number of search steps in either direction.

See Also:

Constant Field Values

KEY_SEARCHOFFSET

public static final String KEY_SEARCHOFFSET

The step with, if focus model is bad.

See Also:

Constant Field Values

KEY_SEARCHORDER

public static final String KEY_SEARCHORDER

The moment during coarse focus.

See Also:

Constant Field Values

KEY_DOSEARCH

public static final String KEY_DOSEARCH

Once the temperature model is accurate enough, we do not search.

See Also:

Constant Field Values

KEY_FOCUSFRAME

public static final String KEY_FOCUSFRAME

The frame for focus images.

See Also:

Constant Field Values

KEY_MOMENTSFRAME

public static final String KEY_MOMENTSFRAME

The frame for focus moments, smaller than image frame.

See Also:

Constant Field Values

KEY_FOCUSBINNING

public static final String KEY_FOCUSBINNING

The binnning for focus images.

See Also:

Constant Field Values

KEY_MAXFOCUSEXPOSE

public static final String KEY_MAXFOCUSEXPOSE

If the exposure time required for moments exceed this, do T only.

See Also:

Constant Field Values

KEY_STEP0

public static final String KEY_STEP0

The focus position for focus temperture T0.

See Also:

Constant Field Values

KEY_TEMP0

public static final String KEY_TEMP0

At this temperature, optimal focus is at step0.

See Also:

Constant Field Values

KEY_STEPTEMP

public static final String KEY_STEPTEMP

Per degree difference to T0, we add this number of steps.

See Also:

Constant Field Values

KEY_DOSAVE

public static final String KEY_DOSAVE

Save the focus sequence images. Always done with String-type ccds.

See Also:

Constant Field Values

KEY_ZERNIKESTEP

public static final String KEY_ZERNIKESTEP

If this multiplier to searchsteps is greater 0, we do Zernikes.

See Also:

Constant Field Values

KEY_ZEXPOSE

public static final String KEY_ZEXPOSE

Multiplier to nominal exposure time for extra/intra focal Zernike.

See Also:

Constant Field Values

KEY_A4SLOPE

public static final String KEY_A4SLOPE

This is the slope of A4 versus steps.

See Also:

Constant Field Values

KEY_A4ERROR

public static final String KEY_A4ERROR

This is the error estimate for A4 slope.

See Also:

Constant Field Values

KEY_BLOBSIZE

public static final String KEY_BLOBSIZE

The default blob size.

See Also:

Constant Field Values

KEY_ADUSIZE

public static final String KEY_ADUSIZE

The box to scan for A4.

See Also:

Constant Field Values

KEY_SKYFRAME

public static final String KEY_SKYFRAME

The default sky frame size.

See Also:

Constant Field Values

KEY_MEDIANSKY

public static final String KEY_MEDIANSKY

If true, use median in background frame.

See Also:

Constant Field Values

KEY_LOWSKYSIGMA

public static final String KEY_LOWSKYSIGMA

If greather than zero, the low-bound sigma for background rejection.

See Also:

Constant Field Values

KEY_HIGHSKYSIGMA

public static final String KEY_HIGHSKYSIGMA

If greather than zero, the high bound sigma for background rejection.

See Also:

Constant Field Values

KEY_ERRORZERNIKE

public static final String KEY_ERRORZERNIKE

If the zernike error is below this, we spare the sequence.

See Also:

Constant Field Values

DEFUNIQUE

private static final String DEFUNIQUE

Default unique parameter name.

See Also:

Constant Field Values

DEFMOMENTS

private static final String DEFMOMENTS

Default moments parameter name.

See Also:

Constant Field Values

DEFSEARCHSTEPS

private static final int DEFSEARCHSTEPS

Default half-number of search steps.

See Also:

Constant Field Values

DEFDOSEARCH

private static final boolean DEFDOSEARCH

If temperature model is accurate enough, we can skip the search.

See Also:

Constant Field Values

DEFEXPOSEFOCUS

private static final double DEFEXPOSEFOCUS

The default S/N on acquire.

See Also:

Constant Field Values

DEFSEARCHORDER

private static final int DEFSEARCHORDER

The moment during coarse focus.

See Also:

Constant Field Values

DEFFOCUSORDER

private static final int DEFFOCUSORDER

The moment during fine focus.

See Also:

Constant Field Values

DEFEXTENSION

private static final int DEFEXTENSION

The moment during fine focus.

See Also:

Constant Field Values

DEFFOCUSBINNING

private static final Dimension DEFFOCUSBINNING

The default binning on acquire.

DEFDOSAVE

private static final boolean DEFDOSAVE

If true we save the indivdual images during focus.

See Also:

Constant Field Values

DEFZERNIKESTEP

private static final double DEFZERNIKESTEP

Default no extra Zernike images.

See Also:

Constant Field Values

DEFZEXPOSE

private static final double DEFZEXPOSE

Default no extra increase in exposure time on Zernikes.

See Also:

Constant Field Values

DEFA4SLOPE

private static final double DEFA4SLOPE

Default A4 slope (2011-10-14).

See Also:

Constant Field Values

DEFA4ERROR

private static final double DEFA4ERROR

Default A4 error (2011-10-14).

See Also:

Constant Field Values

DEFBLOBSIZE

private static final Dimension DEFBLOBSIZE

The default blob size.

DEFADUSIZE

private static final Dimension DEFADUSIZE

The default size around the bright spot.

DEFSKYFRAME

private static final int DEFSKYFRAME

The defautl sky frame size.

See Also:

Constant Field Values

DEFMEDIANSKY

private static final boolean DEFMEDIANSKY

Default we use median for sky-level determination.

See Also:

Constant Field Values

DEFLOWSKYSIGMA

private static final double DEFLOWSKYSIGMA

Per default we do not do ADU rejection, thus this is zero.

See Also:

Constant Field Values

DEFHIGHSKYSIGMA

private static final double DEFHIGHSKYSIGMA

Per default we do not do ADU rejection, thus this is zero.

See Also:

Constant Field Values

DEFERRORZERNIKE

private static final double DEFERRORZERNIKE

Default always do sequence.

See Also:

Constant Field Values

unique

private Parameter unique

The unique parameter.

temp

private Value temp

The value that delivers the temperature relevant for focus model.

moments

private FitsMoments moments

The fits-moments parameter.

expt

private long expt

The exposure time in ms calculated once per focus sequence.

telescope

private Focusable telescope

The object that allows me to set the focus.

ccd

private CcdDriver ccd

The CCD to take images with.

Constructor Detail

MomentsFocusser

public MomentsFocusser(Map<String,String> prop)

Constructor chaining.

Method Detail

registerParameter

public void registerParameter(Parameter p)

We use the parameter, if it is a fitsmoments and if the name agrees with the property KEY_MOMENTS

Specified by:

registerParameter in interface ParameterDepending

registerDriver

public boolean registerDriver(Driver d)

If this driver is a ccd and its name equals KEY_CCD.

Specified by:

registerDriver in interface DriverDepending

Returns:

True if registering at the driver was successful.

registerFocus

public void registerFocus(Focusable f)

We register the object that can set a focus position.

registerExposureTime

public void registerExposureTime(long ms)

The exposure time is set from the outside. It also requires knowledge of the star that was acquired. The time is per convention always in ms.

isValid

public boolean isValid()

Checks, if all required values and objects are in place.

isReady

public boolean isReady()

Checks, if all required values and objects are in place, sparing expt.

crudeFocus

protected double crudeFocus()

We position the linear sledge at the temperature model focus. This position is returned, if applicable, otherwise -1 is returned.

doFocus

public ErrorEvent doFocus()

Task of this object is to auto focus after a successful acquire. This is done in two steps

coarseFocus

private double coarseFocus()

In the coarse focus, we do a temperature model, even if very inaccurate, then procced to in and out with #KEY_SEARCH step, doing a image on the small frame along the offsets. For each image, the value of the KEY_SEARCHORDER moment is recorded, in this list the maximum is found. From this maximum and from its neighbouring values, a parabola is fit through this three points, the maximum is the new focus, which we also set. If the maximum value in the original sequence is at the edge, we return a value slightly inside, depending on the two inner points to the maximum.

Returns:

True on success.

doZernikes

private double doZernikes(double zernike,
                          double pos0)

Does two zernike out-of-focus image and returns true if the focus obtained is good enough.

scanA4

private double scanA4(nom.tam.fits.Fits ff,
                      int use)
               throws nom.tam.fits.FitsException,
                      IOException

We calculate the A4 parameter from second image moments following Equation 5 in PASP118, 1165, but without pixel scaling.

       A4 = sqrt(Mx+My), with

       Mx,y = Σ(x,y_ij-x,y_c)^2*ADU_ij/ΣADU_ij
       

Centered on the brightest pixel blob in the image, we use a rectangle of size KEY_ADUSIZE and around that a #SKYFRAME thick frame for background determination. The background is either the median or the mean of the ADUs in the sky frame, the RMS estimate is either the quartile-sigma or the standard deviation. The two values KEY_LOWSKYSIGMA and KEY_HIGHSKYSIGMA define which range of ADUs should be considered background. This background count is removed from the image prior to calculating the moments.

Throws:

nom.tam.fits.FitsException

IOException

takeSingleImage

private nom.tam.fits.Fits takeSingleImage(CcdDriver ccd,
                                          long ms,
                                          Dimension bin,
                                          String store)

Takes a single image, stores it, if desired.

getMomentAt

private Double[] getMomentAt(double step,
                             int order,
                             String fext)

We position the linear stage at the indicated step, take an image with the CCD camera on the #KEY_FOCSUFRAME and calculate the moments of this image. The value returned is the indicated central normalized moment, except for 1 that returns the average and 2 returns the square root of the variance. If the positioning fails (or if the requested position is out of range) null is returned.

getMomentValue

private Double getMomentValue(CentralMoments cm,
                              int order)

Gets the requested value from our central moments. If the requested order is one, we return the average, if two the standard deviation is returned, otherwise the normalized central moment of this order.