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

bpf_pt

csh-shell script: bpf_pt

NAME
bpf_pt - bandpass filtering for point data (single record or all records)

SYNOPSIS
bpf_pt <plist> <pmask> <SLC_par> <pdata_in> <pdata_out> <rec_num> <type> <MLI_par> <fcf> <bw>

<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)
<pdata_out>	(output) spatially filterd point data stack (same type as pdata_in)
<rec_num>	record number to process (default -: all records)
<type>	input/output data type (0:fcomplex 1:scomplex 2:float)
<MLI_par>	(input) SLC/MLI parameter file of 2-D output image data file
<fcf>	bandpass filter normalized center frequency (-0.5 --> 0.5)
<bw>	bandpass filter normalized bandwidth (range: 0 --> 1.0)

EXAMPLE
bpf_pt testsite.plist testsite.pmask 08256.rslc.par testsite.punw1 testsite.punw2 14 2 08256.rmli.par 0.0 0.05

Conducts a low-pass filtering of record 14 of the point data stack testsite.punw1.

bpf_pt testsite.plist testsite.pmask 08256.rslc.par testsite.pres1 testsite.pres2 - 2 08256.rmli.par 0.0 0.05

Conducts a low-pass filtering of all records of the point data stack testsite.pres1.

bpf_pt testsite.plist testsite.pmask 08256.rslc.par testsite.pres1 testsite.pres2 - 2 08256.rmli.par 0.5 0.95

Conducts a high-pass filtering of all records of the point data stack testsite.pres1. This high-pass filtering corresponds to the complement of \ the low-pass filtering of the previous example.

INSTALLATION
bpf_pt is a csh script in ./IPTA/scripts.

DESCRIPTION
bpf_pt supports the spatial filtering of point data stacks. Either one or all records can be filtered. The filtering procfess consists of a transformation of the point data to a 2-dimensional data sets (using the program pt2data with bilinear interpolation) followed by band-pass filtering (using the program bpf of the ISP software).

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.

Only valid points, i.e. points with a non-zero value in the mask are considered. For points with a zero in the mask the output is set to the NULL value.

The filter is specified in terms of the normalized center frequencies and bandwidths in x (across the image) and y (down). A normalized frequency value of 1.0 is equivalent to the sampling frequency of the data. The filter passband is specified as a fraction of the sampling frequency in the range (0 --> 1.0). Hence a bandwidth of 0.5 reduces the output bandwidth to half of the sampling bandwidth.

OPTIONS
Additional characteristics of the resampling to 2D and filtering can be modified by editing the shell script.

SEE ALSO
spf_pt, ipta.h.