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Output Description

At successful exit the process control flag is switched on:

 subtr_refdem:            1

The output (in the products result file) looks like:

 Additional_azimuth_shift:               1
 Additional_range_shift:                 -2
 Data_output_file:                       Outdata/cint.minrefdem.raw
 Data_output_format:                     complex_real4
 First_line (w.r.t. original_master):    245
 Last_line (w.r.t. original_master):     14964
 First_pixel (w.r.t. original_master):   7
 Last_pixel (w.r.t. original_master):    3998
 Multilookfactor_azimuth_direction:      40
 Multilookfactor_range_direction:        8
 Number of lines (multilooked):          368
 Number of pixels (multilooked):         499
 * End_subtrrefpha:_NORMAL

Figure 27.1 shows the result of subtracting the reference phase of the radarcoded DEM from the interferogram (See Figure 25.1). It can be seen the number of topographic fringes is reduced, though there still remain some residual effects. A next version of Doris will include an option to first correlate the radarcoded DEM with the interferogram, to find an additional offset. The radarcoded reference DEM is then shifted on (multilooked) pixel level before subtraction.

Figure 27.1: Phase image of complex interferogram. The phase of the reference DEM is subtracted ('flat earth' was already subtracted in subtrrefpha), leaving residual topographic, atmospheric, and errorous fringes.

Leijen 2009-04-14