isce3::focus::RangeComp Class Reference

Range compression processor. More...

#include <RangeComp.h>

Public Types
enum class	Mode { Full , Valid , Same }
	Convolution output mode. More...

Public Member Functions
	RangeComp (const std::vector< std::complex< float > > &chirp, int inputsize, int maxbatch=1, Mode mode=Mode::Full)
	Constructor.
int	chirpSize () const
	Number of samples in chirp.
int	inputSize () const
	Expected number of samples in the input signal to be compressed.
int	fftSize () const
	FFT length.
int	maxBatch () const
	Max batch size.
Mode	mode () const
	Output mode.
int	outputSize () const
	Output number of samples.
int	firstValidSample () const
	Return the (zero-based) index of the first fully-focused pixel in the output.
void	applyNotch (double frequency, double bandwidth=0.0)
	Apply a notch to the baseband frequency-domain representation of the chirp reference function.
const std::complex< float > *	chirp_spectrum () const
	Get a pointer to the frequency spectrum of the chirp that will be used for range compression.
void	rangecompress (std::complex< float > *out, const std::complex< float > *in, int batch=1)
	Perform pulse compression on a batch of input signals.

Detailed Description

Range compression processor.

Member Enumeration Documentation

Mode

enum class isce3::focus::RangeComp::Mode

strong

Convolution output mode.

Enumerator
Full	The output contains the full discrete convolution of the input with the matched filter. For an input signal and chirp of size N and M, the output size is (N + M - 1).
Valid	The output contains only the valid discrete convolution of the input with the matched filter. For an input signal and chirp of size N and M, the output size is (max(M, N) - min(M, N) + 1).
Same	The output contains the discrete convolution of the input with the matched filter, cropped to the same size as the input signal.

Constructor & Destructor Documentation

RangeComp()

isce3::focus::RangeComp::RangeComp	(	const std::vector< std::complex< float > > &	chirp,
		int	inputsize,
		int	maxbatch = 1,
		Mode	mode = Mode::Full )

Constructor.

Forms a matched filter from the time-reversed complex conjugate of the chirp replica and creates FFT plans for frequency domain convolution with the matched filter.

Parameters

[in]	chirp	Time-domain replica of the transmitted chirp waveform
[in]	inputsize	Number of range samples in the signal to be compressed
[in]	maxbatch	Max batch size
[in]	mode	Convolution output mode

Member Function Documentation

applyNotch()

void isce3::focus::RangeComp::applyNotch	(	double	frequency,
		double	bandwidth = 0.0 )

Apply a notch to the baseband frequency-domain representation of the chirp reference function.

Parameters

[in]	frequency	Center frequency of the notch normalized by the sample rate, so should be in interval [-0.5, 0.5)
[in]	bandwidth	Total width for the notch taper. If zero, then only the nearest FFT bin will be set to zero.

chirp_spectrum()

const std::complex< float > * isce3::focus::RangeComp::chirp_spectrum ( ) const

inline

Get a pointer to the frequency spectrum of the chirp that will be used for range compression.

Its length is equal to fftSize().

rangecompress()

void isce3::focus::RangeComp::rangecompress	(	std::complex< float > *	out,
		const std::complex< float > *	in,
		int	batch = 1 )

Perform pulse compression on a batch of input signals.

Computes the frequency domain convolution of the input with the reference function.

Exceptions

LengthError

If batch exceeds the max batch size

Parameters

[out]	out	Range-compressed data
[in]	in	Input data
[in]	batch	Input batch size

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

• /home/runner/work/isce3/isce3/cxx/isce3/focus/RangeComp.h
• /home/runner/work/isce3/isce3/cxx/isce3/focus/RangeComp.cpp