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Baseline estimation
Added by Thorsten Seehaus over 7 years ago
Hi,
how are you getting baseline information of TDX data using GAMMA?
I use base_init (mflag=0, use of orbits) to get baseline information, however it differs strongly from the information in th DLR CoSSC data.
Base_init:
method 0: baseline parallel component (m), rate (m/s): -1686.7823 -0.4303
method 0: baseline perpendicular component (m), rate (m/s): -2944.2391 -1.4127
DLR:
<effectiveBaseline>1.46802969457949666E+03</effectiveBaseline>
Replies (5)
Baseline estimation - Added by Charles Werner over 7 years ago
Hello,
Rather than using a polynomial model for the baseline, the baseline is
calculated from the state vectors for each pixel in the image in a method
similar to geocoding, the second satellite is flown along the track until it is
imaging the selected point on the ground. This is done for every point in the
interferogram and avoids the restriction of using a polynomial model. It is also
more accurate.
The program phase_sim_orb is used to calculate the simulated interferogram
without using an explicit polynomial model for the baseline.
base_init was useful in the days before accurate state vectors were available.
Best regards,
Charles Werenr
RE: Baseline estimation - Added by Thorsten Seehaus over 7 years ago
Actually, I am just wondering why there is such a big difference between the GAMMA output and the information provided by DLR.
Which one is is the right one.
Sometime you just want to know the baseline for e.g. database overview, estimation of ph2height sensitivity ...
RE: Baseline estimation - Added by Charles Werner over 7 years ago
Hello,
What Gamma output are you referring to?
The approach used by base_init() does not apply for Tandem-X data.
If you are using phase_sim_orb for Tandem-X data, that you have to use int_mode
0: for Tandem X
RE: Baseline estimation - Added by Thorsten Seehaus over 7 years ago
Hi,
I just want to get the baseline information (length). If I got it right, there is now option to get this value using GAMMA. The log of "phase_sim_orb" does not include any baseline information.
So, I need to take the information from DLR.
RE: Baseline estimation - Added by Charles Werner over 7 years ago
Hello,
for Tandem X certainly use the DLR information. Why do you need the baseline
explicitly? If you need to get the sensitivity of the interferometric phase to
height, that is given by the Gamma program dh_map_orb(). It too has a Tandem-X
mode...