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

sigma_pt

ANSI-C program: sigma_pt.c

NAME
sigma_pt - estimate sigma of unwrapped phase or displacement (float data) using values in a circular region about each point

SYNOPSIS
sigma_pt <plist> <pmask> <pdata> <psigma> [rec_num] [r_max] [w_func] [np_min] [np_max]

<plist>	(input) point list (int)
<pmask>	(input) point data stack of mask values (uchar, set to - to accept all points)
<pdata>	(input) point data stack (various types supported)
<psigma>	(output) standard deviation using points in a circular region
[rec_num]	record number in pdata to process (default -: all records)
[r_max]	maximum search radius (range samples, default: 2)
[w_func]	radial weighting function (0: 1.0 1: 1.0 - radius/r_max, default -: 0)
[np_min]	minimum number of points in the estimate: default: 5
[np_max]	maximum number of points in the estimate: all

EXAMPLE
sigma_pt plist pmsk1 pdisp3 pdisp3_sigma - 3 0 5

determines the standard deviation of the values with a radius of 3 about each point . Uniform weighting is used. The standard deviation
is only estimated if there are a minimum of 5 values within the search radius of each point.

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

DESCRIPTION
Program is used to estimate standard deviation of data values within a specified radius of each point in the data stack. This can be
applied to each individual layer in a data stack. This program is useful only for float data files and can be used to evaluate the standard deviation of deformation, height, or other parameters. There is the option to weight points on the basis of relative distance in the search region.

SEE ALSO
stat_pt.c, ccs_pt.c