ANSI-C program: ERS_fix.c
NAME
ERS_fix - Concatenation of
ERS SAR raw data files, conditioning of raw data, and writing of
PRF to MSP Processing Parameter File.
SYNOPSISERS_fix <station>
<SAR_par> <PROC_par> <cc_flag> <input raw
data file(s)> <output raw data file>
| <ERS_PAF> | ERS receiving/processing facility providing raw
data (valid inputs are: ENVISAT ACRES CCRS COLUMBIA DPAF ESA/ESRIN NASDA EIC CRISP UK/QinetiQ) |
| <SAR_par> | (input) MSP SAR Sensor Parameter File |
| <PROC_par> | (input) MSP Processing Parameter File |
| <cc_flag> | cross-correlation detection of missing lines (0=OFF (default), 1=ON) |
| <raw data file(s)> | (input) One or several input raw data files |
| <output raw data file> | (output) Output conditioned raw data file |
EXAMPLE
ERS_fix EIC ERS_EIC.par
p8560.slc.par 0 8560.raw 8560.fix
ERS_fix UK ERS2_UK.par p8560.slc.par 8560.raw.1 8560.raw.2
8560.raw.3 8560.fix
DESCRIPTION
ERS_fix reads one or several ERS raw data files, checks their
contents and concatenates them into one output raw data file.
This allows you a) to check raw data files for missing or doubled
lines, b) to concatenate raw data files of consecutive frames
into one larger raw data file c) to concatenate the 3 raw data
files per scene provided by the UK-PAF, and CCRS (all prior to
1997) into a single raw data file. ERS_fix requires
information on the line and file header sizes. This information
is provided for a list of receiving stations/processing
facilities. In 1997 the European PAFs harmonized the CEOS leader
format. Currently, the list includes:
| ENVISAT | ERS data in ENVISAT format |
| ACRES | Australian PAF |
| CCRS | Canadian Centre for Remote Sensing PAF |
| COLUMBIA | Columbian S.America PAF |
| CRISP | Singapore receiving station |
| DPAF | German PAF data received and reformatted prior to 1997 |
| EIC | ESA internal format for the VMP processor (not distributed) |
| ESA/ESRIN | All ESA supported receiving stations (D-PAF, I-PAF, ESRIN, UK-PAF) in CEOS format |
| NASDA | ERS data received by NASDA in Japan |
| UK/QinetiQ | ERS data produced by QinetiQ |
A scan of the raw data is performed to determine if the there are any missing lines by checking the line counter in the header of each line and evaluating the line to line correlation coefficient. If lines are missing, a copy or multiple copies of the current line is inserted into the reformatted data stream. In the case where a missing line is detected using the correlation that is not reflected in the line counter, the user will be queried about how many lines they would like to insert into the raw data stream. The situation has occurred with data that was highly corrupted with hundreds of missing lines. The program determines the range delay to the first sample and, if there is a change in the range gate position, aligns all the data to a common range delay. This range delay is written to the Processing Parameter File. The Pulse Repetition Frequency (PRF) given in the raw data is written to the MSP Processing Parameter File. If the PRF changes throughout the raw data a warning is issued and the original PRF is retained.
OPTIONS
New raw data formats may be defined by adding corresponding
stations to the list at the top of the program defining the data
structure containing the parameters describing each PAF raw data
format.
SEE ALSO
Users Guide, typedef_MSP.h.