Gamma DIFF Reference Manual: mk_itab

mk_itab

Perl Script: mk_itab

NAME
mk_itab - Generate ITAB file to calculate interferometric deformation time series with either single or sequential reference SLC

SYNOPSISmk_itab <itab> <max> <step> <stride> <start> -r ref -a

<itab>	(output) ITAB file with 4 columns, text format 1: ref. SLC index from SLC_tab 2: second SLC index of the interferometric pair 3: ITAB file line counter 4: Active flag (0: not included 1: included in time-series analysis)
<max >	(input) number of SLCs in the SLC_tab
<step>	difference in SLC index between the reference and second SLC for each interferogram (default: 1)
<stride>	increment of the index of the starting SLC, if stride is 0, then reference will not change, and the index of the second SLC will increase by step
<start>	index of the first SLC used in generating the itab, (start >= 1)
-r ref	index of the reference SLC when stride is 0, default is the start index
-a	do not generate itab records where the ref. SLC and second SLC have the same index

EXAMPLES

In this example there are a set of 12 SLCs in the SLC_tab, each from a different time. This itab will generate a time series of interferograms, with each interferogram generated from adjacent SLCs in the time series

$mk_itab itab 8 1 1 1

  ITAB file: itab

     1   
  2    1    1

     2   
  3    2    1

     3   
  4    3    1

     4   
  5    4    1

     5   
  6    5    1

     6   
  7    6    1

     7   
  8    7   
  1

In the next example the increment between SLCs has been increasd to 2 and the stride has also been increased to 2. Hence SLCs with index 2, 4, 6, 8, 10 do not appear in the interferogram series.

mk_itab itab_l 12 2
  2 1

  ITAB file: itab_l

     1    3   
  1    1

     3    5   
  2    1

     5    7   
  3    1

     7    9   
  4    1

     9   11   
  5    1

DESCRIPTION

mk_itab is a tool to calculate an ITAB file suited for generating a time-series of differential interferograms. Each line in the ITAB generates a single interferogram when used in conjunction with the mk_diff_2d script family. The first column of the ITAB refers to the line number in the SLC_tab for the reference SLC (SLC-1). The second column is the second SLC (SLC-2) for the interferometric pair. The third column is an ITAB line counter and the fourth column is a flag that denotes if the interferogram should be included in the time-series analysis (0: excluded 1: included). The step parameter refers to the difference between SLC-1 and SLC-2 and the stride is the increment in the SLC number of the reference. The start parameter denotes the SLC index of the starting SLC in the interferogram series. The user can specify the index of the reference SLC for single-reference mode (stride = 0) by using the -r option as in the following example:

mk_itab itab0 8 1 0 1 -r
  4

  ITAB file: itab0

  reference SLC index: 4

     4    1   
  1    1

     4    2   
  2    1

     4    3   
  3    1

     4    4   
  4    1

     4    5   
  5    1

     4    6   
  6    1

     4    7   
  7    1

     4    8   
  8    1

The reference SLC index must be greater than or equal to 1 and refer to an existing record in the SLC_tab.

If the -a option is added, then the generated ITAB will be:

mk_itab itab0 8 1 0 1 -r 4
  -a

  ITAB file: itab0

  reference SLC index: 4

     4    1   
  1    1

     4    2   
  2    1

     4    3   
  3    1

     4    5    4   
  1

     4    6    5   
  1

     4    7    6   
  1

     4    8    7
     1

this avoids generation of an interferogram with 0 phase since the reference and SLC2 are the same file (same index).

SEE ALSO

mk_diff_2d

Copyright for Documentation, Users Guide and Reference Manual by Gamma Remote Sensing, 2015. UW, CW,
last change 11-Apr-2015