GAMMA Interferometric Point Target Analysis Software (IPTA): Reference Manual

ph_coh_pt.c

ANSI-C program: ph_coh_pt.c

NAME
ph_coh_pt - estimate temporal phase coherence for complex or unwrapped phase interferograms

SYNOPSIS
ph_coh_pt <plist> <pmask> <pres> <pccp> [type]

<plist>	(input) point list (int)
<pmask>	(input) point data stack of mask values (uchar, set to - to accept all points)
<pres>	(input) residual phase point data stack (float or fcomplex)
<pccp>	(output) phase coherence (float)
[type]	data type (0:fcomplex 2:float, default -: float)

EXAMPLE
ph_coh_pt plist pmsk1 pres3 pccp3 2

determines phase coherence using temporal phase history of the residual phase for each point in the stack.

INSTALLATION
Source code ph_coh_pt in ./IPTA/src, executable version ph_coh_pt ./IPTA/bin

DESCRIPTION
ph_coh_pt is used estimate the phase coherence of a set of phase values. These phases can be stored either as float data values or as the
phase of a complex data vector where phase = cpx_exp(imag/real). The phase coherence is defined as

ph_coh = 1/N * SUM cexp(-i*(phase_measured_i - phase_model)

where the sum is over the set of measurements for each point. The input phase stack whould be the residual phase after all modelled atmosphere and and deformation signal have
been subtracted. Since the deformation signal consists of both linear and non-linear components, the phase coherence will be dependent on how much of the residual phase is considered as non-linear deformation
by the temporal and spatial filters that have been applied.

The phase coherence can be evaluated both for unwrapped (float format) or wrapped phase (fcomplex format).

SEE ALSO
cct_pt.