There are three ascii output files: one for (results of) processing steps specific to the master, one for the slave, and one for the rest of the processing (the 'products'). These files are referred to as master, slave and product result file (parameter files). For example, the wavelength of the sensor and the filename of the master image can be found in the master result file (and for the slave parameters in the slave result file), while coregistration parameters, which aren't unique to a particular image, can be found in the products result file. These output files serve as input for Doris for running later steps. (Of course, a step also can generate binary data output. This is described in the following chapters.)
The result files all consist of a header and a tail, which grows with the processing.
In the header some general information and an overview of the processing is given with process control flags. (These flags do not imply a certain order.) By convention, each processing step can be run only once (0 or 1 in the process control flag), to avoid confusion on the correct/latest results are. (This implies that a result section in the tail has to be deleted, and the process control flag reset to 0, before running a step a second time.)
In the (growing) tail the results of the processing is stored. The result files are read again and the read parameters are used in the further processing. (In order to trick Doris to use other parameters then the ones that result from a previous processing step, simply edit the result file, e.g, in order to coregister complex interferograms.)
For the master output file the header with the information and the process control flags looks like:
===================================================== MASTER RESULTFILE: master.res Created by: InSAR Processor: Doris (Delft o-o Radar Interferometric Software) Version: Version 4.01 (19-DEC-2008) (optimal) FFTW library: used VECLIB library: not used LAPACK library: not used Compiled at: Dec 19 2008 17:26:52 By GNU gcc: 4.1.4 File creation at: Fri Dec 19 19:08:21 2008 -------------------------------------------------------- | Delft Institute of Earth Observation and Space Systems | | Delft University of Technology | | http://enterprise.lr.tudelft.nl/doris/ | -------------------------------------------------------- Start_process_control readfiles: 0 precise_orbits: 0 crop: 0 sim_amplitude: 0 master_timing: 0 oversample: 0 filt_azi: 0 filt_range: 0 NOT_USED: 0 End_process_control
The last flag (NOT_USED) is reserved for future use. In the slave result file the following line (and processing step) is extra:
resample: 0
and following lines are missing:
sim_amplitude: 0 master_timing: 0
The products result file is build up in the same manner. The process control flags in the header of the products result file are:
[SKIP] [SKIP] Start_process_control coarse_orbits: 0 coarse_correl: 0 fine_coreg: 0 timing_error: 0 dem_assist: 0 comp_coregpm: 0 interfero: 0 coherence: 0 comp_refphase: 0 subtr_refphase: 0 comp_refdem: 0 subtr_refdem: 0 filtphase: 0 unwrap: 0 slant2h: 0 geocoding: 0 dinsar: 0 NOT_USED2: 0 End_process_control [SKIP] [SKIP]
The latter flag is reserved for future use. As already mentioned, after the process control flags the results of a (successfully ran) processing step are appended.
A section of the tail always starts with some lines like
******************************************************************* *_Start_coarse_orbits: *******************************************************************
After which the results for this processing step follow. A section always ends with a statement shown below. (This End_.step:_NORMAL statement is important because the status of the process flag in the header is updated with it.)
****************************************************************** * End_coarse_orbits:_NORMAL ******************************************************************
Note that not all steps that are in the process control flags actually have to be implemented in Doris for the moment. (Unwrapping, extra flags)
Since only one result section is allowed for every processing step, it is not possible to re-run a certain step without editing the result file. The process control flag in the header has to be reset, and the total section in the tail (from Start_step to END:_NORMAL) has to be deleted, or commented out.
If the section is not deleted, Doris will likely exit, but if not, the further processing may be affected, because wrong values may be used (i.e., read from the result file).
It is of course possible to change the results (parameter values, for example correlation value for an estimated offset) in the result files, so that the altered value is used in the further processing. However, if you change the strings describing the output Doris will likely protest (i.e., hang or exit).