A class for estimating one-way or two-way elevation (EL) power pattern from 2-D raw echo data over quasi-homogenous scene and provide approximate look (off-nadir or EL) angle and ellipsoidal incidence angle (no local slope). More...

#include <ElPatternEst.h>

Public Types
using	RowMatrixXcf = isce3::core::EMatrix2D<std::complex<float>>

Public Member Functions
	ElPatternEst (double sr_start, const isce3::core::Orbit &orbit, int polyfit_deg=6, const isce3::geometry::DEMInterpolator &dem_interp={}, double win_ped=0.0, const isce3::core::Ellipsoid &ellips={}, bool center_scale_pf=false)
	A constructor with full input arguments.

	ElPatternEst (double sr_start, const isce3::core::Orbit &orbit, const isce3::geometry::DEMInterpolator &dem_interp)
	A more concise constructor of key inputs.

tuple5_t	powerPattern2way (const Eigen::Ref< const RowMatrixXcf > &echo_mat, double sr_spacing, double chirp_rate, double chirp_dur, std::optional< double > az_time={}, int size_avg=8, bool inc_corr=true) const
	Estimated averaged two-way time-series power pattern in Elevation from 2-D raw echo data uniformly sampled in slant range direction.

tuple5_t	powerPattern1way (const Eigen::Ref< const RowMatrixXcf > &echo_mat, double sr_spacing, double chirp_rate, double chirp_dur, std::optional< double > az_time={}, int size_avg=8, bool inc_corr=true) const
	Estimated averaged one-way time-series power pattern in Elevation from 2-D raw echo data uniformly sampled in slant range direction.

double	winPed () const
	Get raised-cosine window pedestal set at the constructor.

int	polyfitDeg () const
	Get degree of polyfit set at the constructor.

bool	isCenterScalePolyfit () const
	Check whether the polyfit process is centeralized and scaled.

Protected Types
using	Linspace_t = isce3::core::Linspace<double>

using	tuple4_t

using	tuple5_t

Protected Attributes
double	_sr_start

isce3::core::Orbit	_orbit

double	_polyfit_deg

isce3::geometry::DEMInterpolator	_dem_interp

double	_win_ped

isce3::core::Ellipsoid	_ellips

bool	_center_scale_pf

Detailed Description

A class for estimating one-way or two-way elevation (EL) power pattern from 2-D raw echo data over quasi-homogenous scene and provide approximate look (off-nadir or EL) angle and ellipsoidal incidence angle (no local slope).

The final power in dB scale is fit into N-order polynomials as a function of look angle in radians. Required relative radiometric calibration from \(\beta^{0}\) to \(\gamma^{0}\) is done approximately by using slant ranges and ellipsoidal incidence angle.

Member Typedef Documentation

◆ tuple4_t

using isce3::antenna::ElPatternEst::tuple4_t

protected

Initial value:

std::tuple<Eigen::ArrayXd, isce3::core::Linspace<double>,

Eigen::ArrayXd, Eigen::ArrayXd>

◆ tuple5_t

using isce3::antenna::ElPatternEst::tuple5_t

protected

Initial value:

std::tuple<Eigen::ArrayXd, isce3::core::Linspace<double>,

Eigen::ArrayXd, Eigen::ArrayXd, isce3::core::Poly1d>

isce3::core::Poly1d

Data structure for representing 1D polynomials.

Definition Poly1d.h:23

Constructor & Destructor Documentation

◆ ElPatternEst() [1/2]

isce3::antenna::ElPatternEst::ElPatternEst	(	double	sr_start,
		const isce3::core::Orbit &	orbit,
		int	polyfit_deg = 6,
		const isce3::geometry::DEMInterpolator &	dem_interp = {},
		double	win_ped = 0.0,
		const isce3::core::Ellipsoid &	ellips = {},
		bool	center_scale_pf = false )

A constructor with full input arguments.

Parameters

[in]	sr_start	start slant range in (m)
[in]	orbit	isce3 Orbit object
[in]	polyfit_deg	(optional) polyfit degree of polynomial for polyfitting estimated power patterns. The value must be > 1. Default is 6. @pram[in] dem_interp (optional) isce3 DEMInterpolator object. Default is global 0.0 (m) height (reference ellipsoid). Note that simply averaged DEM will be used. No local slope is taken into account!
[in]	win_ped	(optional) Raised-cosine window pedestal. A value within [0, 1]. Default is Hann window.https://en.wikipedia.org/wiki/Hann_function See raised cosine window.
[in]	ellips	(optional) isce3 Ellipsoid object. Default is WGS84.
[in]	center_scale_pf	(optional) whether or not use center and scaling in polyfit. Default is false.

Exceptions

InvalidArgument

◆ ElPatternEst() [2/2]

isce3::antenna::ElPatternEst::ElPatternEst	(	double	sr_start,
		const isce3::core::Orbit &	orbit,
		const isce3::geometry::DEMInterpolator &	dem_interp )

inline

A more concise constructor of key inputs.

Parameters

[in]	sr_start	start slant range in (m)
[in]	orbit	isce3 Orbit object
[in]	dem_interp	isce3 DEMInterpolator object.

Exceptions

InvalidArgument

Member Function Documentation

◆ isCenterScalePolyfit()

bool isce3::antenna::ElPatternEst::isCenterScalePolyfit ( ) const

inline

Check whether the polyfit process is centeralized and scaled.

Returns: bool

◆ polyfitDeg()

int isce3::antenna::ElPatternEst::polyfitDeg ( ) const

inline

Get degree of polyfit set at the constructor.

Returns: degree of polyfit used for 1-way or 2-way power pattern (dB) as a function of look angles (rad).

◆ powerPattern1way()

ElPatternEst::tuple5_t isce3::antenna::ElPatternEst::powerPattern1way	(	const Eigen::Ref< const RowMatrixXcf > &	echo_mat,
		double	sr_spacing,
		double	chirp_rate,
		double	chirp_dur,
		std::optional< double >	az_time = {},
		int	size_avg = 8,
		bool	inc_corr = true ) const

Estimated averaged one-way time-series power pattern in Elevation from 2-D raw echo data uniformly sampled in slant range direction.

Uniform sampling in azimuth direction is not required! Note that it is assumed the data either has no TX gap (bad values) or its TX gap (bad values) have been already replaced by meaningful data.

Parameters

[in]	echo_mat	raw echo matrix, a row-major Eigen matrix of type complex float. The rows represent range lines. The matrix shape is pulses (azimuth bins) by range bins.
[in]	sr_spacing	slant range spacing in (m).
[in]	chirp_rate	transmit chirp rate in (Hz/sec).
[in]	chirp_dur	transmit chirp duration in (sec).
[in]	az_time	(optional) relative azimuth time in seconds w.r.t reference epoch time of orbit object. Default is the mid orbit time if not specified or if set to {} or std::nullopt.
[in]	size_avg	(optional) the block size for averaging in slant range direction. Default is 8.
[in]	inc_corr	(optional) whether or not apply correction for incidence angles calculated at a certain mean DEM height wrt reference ellipsoid w/o taking into account any local slope! Default is true.

Returns: eigen vector of times-series range-averaged peak-normalized 1-way power pattern in (dB) which is uniformly sampled in slant range with new range spacing defined by "sr_spacing * size_avg".; slant ranges in meters in the form of isce3 Linspace object; look angles vector in radians.; ellipsoidal incidence angles vector in radians.; isce3 Poly1d object mapping power in dB as a function look angle in radians

Exceptions

InvalidArgument,RuntimeError

See also: powerPattern2way()

◆ powerPattern2way()

ElPatternEst::tuple5_t isce3::antenna::ElPatternEst::powerPattern2way	(	const Eigen::Ref< const RowMatrixXcf > &	echo_mat,
		double	sr_spacing,
		double	chirp_rate,
		double	chirp_dur,
		std::optional< double >	az_time = {},
		int	size_avg = 8,
		bool	inc_corr = true ) const

Estimated averaged two-way time-series power pattern in Elevation from 2-D raw echo data uniformly sampled in slant range direction.

Uniform sampling in azimuth direction is not required! Note that it is assumed the data either has no TX gap (bad values) or its TX gap (bad values) have been already replaced by meaningful data.

Parameters

[in]	echo_mat	raw echo matrix, a row-major Eigen matrix of type complex float. The rows represent range lines. The matrix shape is pulses (azimuth bins) by range bins.
[in]	sr_spacing	slant range spacing in (m).
[in]	chirp_rate	transmit chirp rate in (Hz/sec).
[in]	chirp_dur	transmit chirp duration in (sec).
[in]	az_time	(optional) relative azimuth time in seconds w.r.t reference epoch time of orbit object. Default is the mid orbit time if not specified or if set to {} or std::nullopt.
[in]	size_avg	(optional) the block size for averaging in slant range direction. Default is 8.
[in]	inc_corr	(optional) whether or not apply correction for incidence angles calculated at a certain mean DEM height wrt reference ellipsoid w/o taking into account any local slope! Default is true.

Returns: eigen vector of times-series range-averaged peak-normalized 2-way power pattern in (dB) which is uniformly sampled in slant range with new range spacing defined by "sr_spacing * size_avg".; slant ranges in meters in the form of isce3 Linspace object; look angles vector in radians.; ellipsoidal incidence angles vector in radians.; isce3 Poly1d object mapping power in dB as a function look angle in radians

Exceptions

InvalidArgument,RuntimeError

See also: powerPattern1way()

◆ winPed()

double isce3::antenna::ElPatternEst::winPed ( ) const

inline

Get raised-cosine window pedestal set at the constructor.

Returns: window pedestal used for weighting ref chirp in range compression.

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

/home/runner/work/isce3/isce3/cxx/isce3/antenna/ElPatternEst.h
/home/runner/work/isce3/isce3/cxx/isce3/antenna/ElPatternEst.cpp

Public Types

Public Member Functions

Protected Types

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ tuple4_t

◆ tuple5_t

Constructor & Destructor Documentation

◆ ElPatternEst() [1/2]

◆ ElPatternEst() [2/2]

Member Function Documentation

◆ isCenterScalePolyfit()

◆ polyfitDeg()

◆ powerPattern1way()

◆ powerPattern2way()

◆ winPed()