ANSI-C program: DELFT_proc2.c
NAME
DELFT_proc2 - Extract
and interpolate Delft ERS-1, ERS-2, and ENVISAT state vectors for
the MSP
SYNOPSIS
DELFT_proc
<PROC_par> <DELFT_dir> [nstate] [interval]
[ODR]
| <PROC_par> | MSP processing parameter file |
| <DELFT_dir> | directory containing Delft orbit arclist and ODR files
for ERS-1, ERS-2 or ENVISAT) NOTE: enter . to specify the current directory |
| [nstate] | number of state vectors to generate (enter - for
default (>= 11) |
| [interval] | time interval between state vectors in the ISP image parameter file (s) (default: 10.0) |
| [ODR] | ODR file to use (include path) rather than ODR file determined from the Delft orbit arclist |
EXAMPLE
DELFT_proc2 p199960421.slc.par
/raid/Delft/ers1/eigen.gl04s
DESCRIPTION
DELFT_proc2 uses ERS-1, ERS-2, and ENVISAT position
state vectors available by the Technical University of Delft to
generate position and velocity state vectors for use by the
MSP. Details on the Delft orbit data are available at the
web site http://www.deos.tudelft.nl/ers/precorbs.
The orbit position data from Delft is provided as binary Orbital
Data Record (ODR) files along with an arclist text file
specifying the start and stop times for each of the ODR files.
Recently these state vectors have been recomputed and the
improved orbit data are available from http://www.deos.tudelft.nl/AS/pieter/Local/ERS/index.html.
The MSP state vectors include both the position and velocity. Since the ODR data provide only the platform position, DELFT_proc2 calculates the velocity vector for each state vector in the ODR file. DELFT_proc2 calculates the number of state vectors required to cover the scene with sufficient overlap of the scene start and end.. The default number of state vectors is 7, though any value up to 64 can be specifiied on the command line.
The time interval between the ODR state vectors in the original DELFT state vectors 60 seconds. This has been reduced to 30 seconds in the reprocessed data. DELFT_proc2 resamples the state vector data to evenly spaced set of vectors (default 10.0 sec interval) and writes the interpolated state vectors into the MSP processing parameter file. The default time interval value should be at least 5 sec. Furthermore there should be several state vectors both before and after the data interval to obtain the most accurate interpolation in the MSP processing.
Each ODR data have best accuracy after a time specified in the ODR header that is some hours after the time of the first state vector in the ODR file. In cases where no ODR file is available with the data at the highest accuracy, the user can specify a specific ODR file to use on the command line. DELFT_proc2 checks to see if the ODR file covers the time period of the SAR data file.
SEE ALSO
Users Guide, typedef_MSP.h, MSP Processing Parameter File.