ANSI-C program: expand_data_pt.c
NAME
expand_data_pt - resample point data using an initial list and
data stack values (single record or all records)
SYNOPSIS
expand_data_pt <plist> <pmask>
<SLC_par> <pdata_in> <plist_out>
<pmask_out> <pdata_out> [rec_num] [type] [r_max]
[w_func] [np_max]
| <plist> | (input) point list (int) |
| <pmask> | (input) point data stack of mask values (uchar, set to - to accept all points) |
| <SLC_par> | (input) SLC parameter file of point list coordinates |
| <pdata_in> | (input) point data stack (various types supported) |
| <plist_out> |
(input) list of points to
resample pdata_in |
| <pmask_out> |
(input) output data mask
for plist_out |
| <pdata_out> | (output) spatially filterd point data stack (same type as pdata_in) |
| [rec_num] | record number in pdata_in and pdata_out to process (default -: all records) |
| [type] | data type (0:fcomplex 1:scomplex 2:float, default -: float) |
| [r_max] | maximum radius (range samples, default: 64) |
| [w_func] | radial weighting function (0: 1.0 1: 1.0-radius/r_max) |
| [np_max] | maximum number of neighbor points in the filter (default - : all points within search radius) |
| pt_num |
point number for local
filtering about a single point (beginning with 0) |
EXAMPLE
expand_data_pt site.plist site.pmask 08256.rslc.par
site.punw1 site.plist2 - site.punw2 14 2 25 1 12
Performs spatial resampling of record 14 of the point data
stack site.punw1. Points within a radius of 25 SLC range samples
are identified, ordered by distance, and the nearest 12 (or
fewer) used for resampling the data at points specified by
site.plist2. The resampled data is written to record 14 of
site.punw2.
expand_data_pt site.plist site.pmask 08256.rslc.par site.punw1 site.plist2 - site.punw2 - 2 25 1 -1
Performs spatial resampling of all records of the point data
stack site.punw1. All points within a radius of 25 SLC range
samples are identifed, ordered by distance, and the nearest 12
(or fewer) are used for resampling the data at point locations
specified by site.plist2. The resampled data are written to
the output stack site.punw2.
expand_data_pt site.plist site.pmask 08256.rslc.par site.punw1 site.plist2 - site.punw2 - 2 200 1 12
Performs spatial resampling of all records of the point data
stack site.punw1. All points within a very large radius (of
200 SLC range samples) are identified, ordered by distance, and
the nearest 12 (or fewer) are used for the resampling using
convolutional interpolation. In this case the criteria
corresponds for the vast majority of points to "using the 12
nearest points".
INSTALLATION
Source code expand_data_pt.c in ./IPTA/src, executable version
expand_data_pt in ./IPTA/bin
DESCRIPTION
expand_data_pt supports the spatial resampling of point data
stacks. Either one or all records can be resampled. The points to
be considered in the resampling can be indicated through the
spatial radius (indicated in range samples) and the maximum
number of points considered, or just one of the two criteria by
selecting all records in the other criteria.
Together with the point list a point data stack of mask values
can be indicated to consider or ignor specific points. "-" can be
indicated instead a pmask file to consider all points of the
list.
Either one record or all records can be filtered. To select all
records "-" is indicated instead of a record number. Different
format types (0:fcomplex 1:scomplex 2:float, default -: float)
are supported. The format of the output point data stack with the
filtered values has the same type as the input point data
stack.
The SLC parameter file of point list coordinates is required to calculate ground distances between pairs of points. Such distances are calculated using the ground range sampling (calculated from slant range sampling and incidence angle) and the azimuth spacing. The maximum search area radius is indicated in SLC range samples.
Only valid points, i.e. points with a non-zero value in the
mask are considered.
For the spatial filtering constant weights or a linearly
decreasing ramp (linear with ground distance) can be selected.
Points with NULL values in the input data are not considered in
the search for the nearest points (they are not counted as points
in the filtering).
OPTIONS
none.
SEE ALSO
ipta.h.