#include <AntennaIntervalConstraint.h>

Inheritance diagram for dp3::ddecal::AntennaIntervalConstraint:

Public Member Functions
	AntennaIntervalConstraint (const std::vector< size_t > &antenna_averaging_factors)

void	Apply (SolutionSpan &solutions, double time) override

const std::vector< size_t > &	GetIntervalsPerAntenna () const

void	Initialize (size_t n_antennas, const std::vector< uint32_t > &solutions_per_direction, const std::vector< double > &frequencies) override

Public Member Functions inherited from dp3::ddecal::Constraint
virtual	~Constraint ()=default

void	ApplyReferenceAntenna (SolutionSpan &solutions)

virtual std::vector< ConstraintResult >	GetResult () const

uint32_t	GetSubSolutions (size_t direction) const

virtual void	GetTimings ([[maybe_unused]] std::ostream &os, [[maybe_unused]] double duration) const

size_t	NAntennas () const

size_t	NChannelBlocks () const

size_t	NDirections () const

size_t	NSubSolutions () const

virtual void	PrepareIteration ([[maybe_unused]] bool hasReachedPrecision, [[maybe_unused]] size_t iteration, [[maybe_unused]] bool finalIter)

virtual bool	Satisfied () const

virtual void	SetSubSolutionWeights (const std::vector< std::vector< double >> &solution_weights)

virtual void	SetWeights ([[maybe_unused]] const std::vector< double > &weights)

Additional Inherited Members
Public Types inherited from dp3::ddecal::Constraint
typedef std::complex< double >	dcomplex

Static Public Member Functions inherited from dp3::ddecal::Constraint
static bool	isfinite (const dcomplex &value)

Detailed Description

This constraint allows using different intervals for different antennas. It does this by averaging solutions of the same antenna but from different sub-intervals together.

Ionospheric effects vary more strongly in time and frequency for more distant stations (relative to a central reference station). Thus, by using shorter time intervals and less frequency smoothing for more distant groups of stations, these fast variations can be captured without adding too much additional free parameters for more central stations. Antenna intervals and smoothing depend on the expected variation per group of antenna. For LOFAR, CS can typically have at least 8 times longer intervals compared to RS.

This constraint works together with the "direction-dependent intervals" setting. If only antenna-dependent intervals are desired, the solutions-per-direction setting should be set to the maximum antenna averaging factor. E.g., with antenna_averaging_factors = {3, 6, 1}, the solutions_per_direction is set to 6 for all directions. This will use a time interval of 1/2, 1 and 1/6 solution interval for the antennas 0, 1 and 2, respectively.

Directional and antenna dependence can be combined, in which case the two work cummulatively. That is, with a setting of antenna_averaging_factors = {3, 6, 1} and solutions_per_direction = {6, 6, 1, 1} for direction 0 and 1, the solver will divide the solution interval into 6 subsolutions. For antenna 0, every 3 of those will be averaged together. For directions 2 and 3, there is only 1 subsolution available, so no averaging is performed for any of the antennas.

Constructor & Destructor Documentation

◆ AntennaIntervalConstraint()

dp3::ddecal::AntennaIntervalConstraint::AntennaIntervalConstraint ( const std::vector< size_t > & antenna_averaging_factors )

inline

Member Function Documentation

◆ Apply()

void dp3::ddecal::AntennaIntervalConstraint::Apply	(	SolutionSpan &	solutions,
		double	time
	)

overridevirtual

This method applies the constraints to the solutions.

Parameters

solutions	A 4D array with dimensions n_channel_blocks x n_antennas x n_sub_solutions x n_pol solutions. n_pol is the dimension with the fastest changing index. Using a span instead of a real tensor as argument type avoids the need for copying data in Python bindings.
time	Central time of interval.

Implements dp3::ddecal::Constraint.

◆ GetIntervalsPerAntenna()

const std::vector<size_t>& dp3::ddecal::AntennaIntervalConstraint::GetIntervalsPerAntenna ( ) const

inline

◆ Initialize()

void dp3::ddecal::AntennaIntervalConstraint::Initialize	(	size_t	n_antennas,
		const std::vector< uint32_t > &	solutions_per_direction,
		const std::vector< double > &	frequencies
	)

overridevirtual

Perform common constraint initialization. Should be overridden when something more than assigning dimensions is needed (e.g. resizing vectors).

Parameters

frequencies For each channel block, the mean frequency.

Reimplemented from dp3::ddecal::Constraint.

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

AntennaIntervalConstraint.h

Public Member Functions