lsst::meas::extensions::photometryKron::KronFluxAlgorithm Class Reference

A measurement algorithm that estimates flux using Kron photometry. More...

#include <photometryKron.h>

Inheritance diagram for lsst::meas::extensions::photometryKron::KronFluxAlgorithm:

Public Types
typedef KronFluxControl	Control
	A typedef to the Control object for this algorithm, defined above.

Public Member Functions
	KronFluxAlgorithm (Control const &ctrl, std::string const &name, afw::table::Schema &schema, daf::base::PropertySet &metadata)
	A class that knows how to calculate fluxes using the KRON photometry algorithm.
virtual void	measure (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure) const
	Called to measure a single child source in an image.
virtual void	measureForced (afw::table::SourceRecord &measRecord, afw::image::Exposure< float > const &exposure, afw::table::SourceRecord const &refRecord, afw::geom::SkyWcs const &refWcs) const
	Called to measure a single child source in an image.
virtual void	fail (afw::table::SourceRecord &measRecord, meas::base::MeasurementError *error=NULL) const
	Handle an exception thrown by the current algorithm by setting flags in the given record.
void	measureNForced (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure, afw::table::SourceCatalog const &refRecord, afw::geom::SkyWcs const &refWcs) const override
	Called to simultaneously measure all children in a deblend family, in a single image.
virtual void	measureN (afw::table::SourceCatalog const &measCat, afw::image::Exposure< float > const &exposure) const
	Called to simultaneously measure all children in a deblend family, in a single image.
std::string	getLogName () const

Static Public Member Functions
static meas::base::FlagDefinitionList const &	getFlagDefinitions ()

Static Public Attributes
static meas::base::FlagDefinition const	FAILURE = flagDefinitions.addFailureFlag( "general failure flag, set if anything went wrong")
static meas::base::FlagDefinition const	EDGE = flagDefinitions.add("flag_edge", "bad measurement due to image edge")
static meas::base::FlagDefinition const	BAD_SHAPE_NO_PSF = flagDefinitions.add("flag_bad_shape_no_psf", "bad shape and no PSF")
static meas::base::FlagDefinition const	NO_MINIMUM_RADIUS = flagDefinitions.add("flag_no_minimum_radius", "minimum radius could not enforced: no minimum value or PSF")
static meas::base::FlagDefinition const	NO_FALLBACK_RADIUS = flagDefinitions.add("flag_no_fallback_radius", "no minimum radius and no PSF provided")
static meas::base::FlagDefinition const	BAD_RADIUS = flagDefinitions.add("flag_bad_radius", "bad Kron radius")
static meas::base::FlagDefinition const	USED_MINIMUM_RADIUS = flagDefinitions.add("flag_used_minimum_radius", "used the minimum radius for the Kron aperture")
static meas::base::FlagDefinition const	USED_PSF_RADIUS = flagDefinitions.add("flag_used_psf_radius", "used the PSF Kron radius for the Kron aperture")
static meas::base::FlagDefinition const	SMALL_RADIUS = flagDefinitions.add("flag_small_radius", "measured Kron radius was smaller than that of the PSF")
static meas::base::FlagDefinition const	BAD_SHAPE = flagDefinitions.add("flag_bad_shape", "shape for measuring Kron radius is bad; used PSF shape")

Protected Attributes
std::string	_logName

Detailed Description

A measurement algorithm that estimates flux using Kron photometry.

Definition at line 90 of file photometryKron.h.

Member Typedef Documentation

Control

typedef KronFluxControl lsst::meas::extensions::photometryKron::KronFluxAlgorithm::Control

A typedef to the Control object for this algorithm, defined above.

The control object contains the configuration parameters for this algorithm.

Definition at line 108 of file photometryKron.h.

Constructor & Destructor Documentation

KronFluxAlgorithm()

lsst::meas::extensions::photometryKron::KronFluxAlgorithm::KronFluxAlgorithm	(	Control const &	ctrl,
		std::string const &	name,
		afw::table::Schema &	schema,
		daf::base::PropertySet &	metadata )

A class that knows how to calculate fluxes using the KRON photometry algorithm.

/

Definition at line 372 of file KronPhotometry.cc.

  : _name(name),
    _ctrl(ctrl),
    _fluxResultKey(
        meas::base::FluxResultKey::addFields(schema, name, "flux from Kron Flux algorithm")
    ),
    _radiusKey(schema.addField<float>(name + "_radius", "Kron radius (sqrt(a*b))")),
    _radiusForRadiusKey(schema.addField<float>(name + "_radius_for_radius",
                            "radius used to estimate <radius> (sqrt(a*b))")),
    _psfRadiusKey(schema.addField<float>(name + "_psf_radius", "Radius of PSF")),
    _centroidExtractor(schema, name, true)
{
    _flagHandler = meas::base::FlagHandler::addFields(schema, name, getFlagDefinitions());
    auto metadataName = name + "_nRadiusForflux";
    boost::to_upper(metadataName);
    metadata.add(metadataName, ctrl.nRadiusForFlux);
}

Member Function Documentation

fail()

void lsst::meas::extensions::photometryKron::KronFluxAlgorithm::fail ( afw::table::SourceRecord & measRecord, meas::base::MeasurementError * error = NULL ) const

virtual

Handle an exception thrown by the current algorithm by setting flags in the given record.

fail() is called by the measurement framework when an exception is allowed to propagate out of one the algorithm's measure() methods. It should generally set both a general failure flag for the algorithm as well as a specific flag indicating the error condition, if possible. To aid in this, if the exception was an instance of MeasurementError, it will be passed in, carrying information about what flag to set.

An algorithm can also to chose to set flags within its own measure() methods, and then just return, rather than throw an exception. However, fail() should be implemented even when all known failure modes do not throw exceptions, to ensure that unexpected exceptions thrown in lower-level code are properly handled.

Implements lsst::meas::base::BaseAlgorithm.

Definition at line 394 of file KronPhotometry.cc.

        {
    _flagHandler.handleFailure(measRecord, error);
}

getFlagDefinitions()

base::FlagDefinitionList const & lsst::meas::extensions::photometryKron::KronFluxAlgorithm::getFlagDefinitions ( )

static

Definition at line 66 of file KronPhotometry.cc.

                                                                     {
    return flagDefinitions;
}

getLogName()

std::string lsst::meas::base::BaseAlgorithm::getLogName ( ) const

inlineinherited

Definition at line 66 of file Algorithm.h.

{ return _logName; }

measure()

void lsst::meas::extensions::photometryKron::KronFluxAlgorithm::measure ( afw::table::SourceRecord & measRecord, afw::image::Exposure< float > const & exposure ) const

virtual

Called to measure a single child source in an image.

Before this method is called, all neighbors will be replaced with noise, using the outputs of the deblender. Outputs should be saved in the given SourceRecord, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

Implements lsst::meas::base::SingleFrameAlgorithm.

Definition at line 461 of file KronPhotometry.cc.

                             {
    geom::Point2D center = _centroidExtractor(source, _flagHandler);
 
    // Did we hit a condition that fundamentally prevented measuring the Kron flux?
    // Such conditions include hitting the edge of the image and bad input shape, but not low signal-to-noise.
    bool bad = false;
 
    afw::image::MaskedImage<float> const& mimage = exposure.getMaskedImage();
 
    double R_K_psf = -1;
    if (exposure.getPsf()) {
        R_K_psf = calculatePsfKronRadius(exposure.getPsf(), center, _ctrl.smoothingSigma);
    }
 
    //
    // Get the shape of the desired aperture
    //
    afw::geom::ellipses::Axes axes;
    if (!source.getShapeFlag()) {
        axes = source.getShape();
    } else {
        bad = true;
        if (!exposure.getPsf()) {
            throw LSST_EXCEPT(
                meas::base::MeasurementError,
                BAD_SHAPE_NO_PSF.doc,
                BAD_SHAPE_NO_PSF.number
            );
        }
        axes = exposure.getPsf()->computeShape(exposure.getPsf()->getAveragePosition());
        _flagHandler.setValue(source, BAD_SHAPE.number, true);
    }
    if (_ctrl.useFootprintRadius) {
        afw::geom::ellipses::Axes footprintAxes(source.getFootprint()->getShape());
        // if the Footprint's a disk of radius R we want footRadius == R.
        // As <r^2> = R^2/2 for a disk, we need to scale up by sqrt(2)
        footprintAxes.scale(::sqrt(2));
 
        double radius0 = axes.getDeterminantRadius();
        double const footRadius = footprintAxes.getDeterminantRadius();
 
        if (footRadius > radius0*_ctrl.nSigmaForRadius) {
            radius0 = footRadius/_ctrl.nSigmaForRadius; // we'll scale it up by nSigmaForRadius
            axes.scale(radius0/axes.getDeterminantRadius());
        }
    }
 
    std::shared_ptr<KronAperture> aperture;
    if (_ctrl.fixed) {
        aperture.reset(new KronAperture(source));
    } else {
        try {
            aperture = KronAperture::determineRadius(mimage, axes, center, _ctrl);
        } catch (pex::exceptions::OutOfRangeError& e) {
            // We hit the edge of the image: no reasonable fallback or recovery possible
            throw LSST_EXCEPT(
                meas::base::MeasurementError,
                EDGE.doc,
                EDGE.number
            );
        } catch (BadKronException& e) {
            // Not setting bad=true because we only failed due to low S/N
            aperture = _fallbackRadius(source, R_K_psf, e);
        } catch(pex::exceptions::Exception& e) {
            bad = true; // There's something fundamental keeping us from measuring the Kron aperture
            aperture = _fallbackRadius(source, R_K_psf, e);
        }
    }
 
    /*
     * Estimate the minimum acceptable Kron radius as the Kron radius of the PSF or the
     * provided minimum radius
     */
 
    // Enforce constraints on minimum radius
    double rad = aperture->getAxes().getDeterminantRadius();
    if (_ctrl.enforceMinimumRadius) {
        double newRadius = rad;
        if (_ctrl.minimumRadius > 0.0) {
            if (rad < _ctrl.minimumRadius) {
                newRadius = _ctrl.minimumRadius;
                _flagHandler.setValue(source, USED_MINIMUM_RADIUS.number, true);
            }
        } else if (!exposure.getPsf()) {
            throw LSST_EXCEPT(
                meas::base::MeasurementError,
                NO_MINIMUM_RADIUS.doc,
                NO_MINIMUM_RADIUS.number
            );
        } else if (rad < R_K_psf) {
            newRadius = R_K_psf;
            _flagHandler.setValue(source, USED_PSF_RADIUS.number, true);
        }
        if (newRadius != rad) {
            aperture->getAxes().scale(newRadius/rad);
            _flagHandler.setValue(source, SMALL_RADIUS.number, true); // guilty after all
        }
    }
 
    _applyAperture(source, exposure, *aperture);
    source.set(_radiusForRadiusKey, aperture->getRadiusForRadius());
    source.set(_psfRadiusKey, R_K_psf);
    if (bad) _flagHandler.setValue(source, FAILURE.number, true);
}

measureForced()

void lsst::meas::extensions::photometryKron::KronFluxAlgorithm::measureForced ( afw::table::SourceRecord & measRecord, afw::image::Exposure< float > const & exposure, afw::table::SourceRecord const & refRecord, afw::geom::SkyWcs const & refWcs ) const

virtual

Called to measure a single child source in an image.

Before this method is called, all neighbors will be replaced with noise, using the outputs of the deblender. Outputs should be saved in the given SourceRecord, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

Reimplemented from lsst::meas::base::SimpleAlgorithm.

Definition at line 569 of file KronPhotometry.cc.

            {
    geom::Point2D center = _centroidExtractor(measRecord, _flagHandler);
    auto xytransform = afw::geom::makeWcsPairTransform(refWcs, *exposure.getWcs());
    _applyForced(measRecord, exposure, center, refRecord,
                    linearizeTransform(*xytransform, refRecord.getCentroid())
                );
 
}

measureN()

void lsst::meas::base::SingleFrameAlgorithm::measureN ( afw::table::SourceCatalog const & measCat, afw::image::Exposure< float > const & exposure ) const

virtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Definition at line 31 of file Algorithm.cc.

                                                                                   {
    throw LSST_EXCEPT(pex::exceptions::LogicError, "measureN not implemented for this algorithm");
}

measureNForced()

void lsst::meas::base::SimpleAlgorithm::measureNForced ( afw::table::SourceCatalog const & measCat, afw::image::Exposure< float > const & exposure, afw::table::SourceCatalog const & refRecord, afw::geom::SkyWcs const & refWcs ) const

inlineoverridevirtualinherited

Called to simultaneously measure all children in a deblend family, in a single image.

Outputs should be saved in the given SourceCatalog, which can also be used to obtain centroid (see SafeCentroidExtractor) and shape (see SafeShapeExtractor) information.

The default implementation simply throws an exception, indicating that simultaneous measurement is not supported.

Reimplemented from lsst::meas::base::ForcedAlgorithm.

Definition at line 179 of file Algorithm.h.

                                                                            {
        measureN(measCat, exposure);
    }

Member Data Documentation

_logName

std::string lsst::meas::base::BaseAlgorithm::_logName

protectedinherited

Definition at line 69 of file Algorithm.h.

BAD_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::BAD_RADIUS = flagDefinitions.add("flag_bad_radius", "bad Kron radius")

static

Definition at line 100 of file photometryKron.h.

BAD_SHAPE

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::BAD_SHAPE = flagDefinitions.add("flag_bad_shape", "shape for measuring Kron radius is bad; used PSF shape")

static

Definition at line 104 of file photometryKron.h.

BAD_SHAPE_NO_PSF

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::BAD_SHAPE_NO_PSF = flagDefinitions.add("flag_bad_shape_no_psf", "bad shape and no PSF")

static

Definition at line 97 of file photometryKron.h.

EDGE

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::EDGE = flagDefinitions.add("flag_edge", "bad measurement due to image edge")

static

Definition at line 96 of file photometryKron.h.

FAILURE

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::FAILURE = flagDefinitions.addFailureFlag( "general failure flag, set if anything went wrong")

static

Definition at line 95 of file photometryKron.h.

NO_FALLBACK_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::NO_FALLBACK_RADIUS = flagDefinitions.add("flag_no_fallback_radius", "no minimum radius and no PSF provided")

static

Definition at line 99 of file photometryKron.h.

NO_MINIMUM_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::NO_MINIMUM_RADIUS = flagDefinitions.add("flag_no_minimum_radius", "minimum radius could not enforced: no minimum value or PSF")

static

Definition at line 98 of file photometryKron.h.

SMALL_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::SMALL_RADIUS = flagDefinitions.add("flag_small_radius", "measured Kron radius was smaller than that of the PSF")

static

Definition at line 103 of file photometryKron.h.

USED_MINIMUM_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::USED_MINIMUM_RADIUS = flagDefinitions.add("flag_used_minimum_radius", "used the minimum radius for the Kron aperture")

static

Definition at line 101 of file photometryKron.h.

USED_PSF_RADIUS

base::FlagDefinition const lsst::meas::extensions::photometryKron::KronFluxAlgorithm::USED_PSF_RADIUS = flagDefinitions.add("flag_used_psf_radius", "used the PSF Kron radius for the Kron aperture")

static

Definition at line 102 of file photometryKron.h.

---

The documentation for this class was generated from the following files:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.1.0/Linux/meas_extensions_photometryKron/g64539dfbff+9f17e571f4/include/lsst/meas/extensions/photometryKron.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-12.1.0/Linux/meas_extensions_photometryKron/g64539dfbff+9f17e571f4/src/KronPhotometry.cc