Dear all, Dear Patrick
Thank you! I didn't expect this to happen so quickly! I had the time to
play around a bit and it seems to work nicely. Attached is an extended
example cfile with 3D atmosphere, wind, and freq shift.
Two _minor_ things I noticed:
1) If the frequency grid f_grid is very narrow at certain points (~< 100
kHz, intentionally or by mistake with VectorInsertGridPoints) the
sensor.cc throws an error:
arts: /opt/arts-dev/arts/src/sensor.cc:1447: void
integration_func_by_vecmult(VectorView, ConstVectorView,
ConstVectorView, ConstVectorView): Assertion `is_increasing( x_f_in )'
failed.
Aborted (core dumped)
To reproduce, increase the number of points in line 56 from 101 to 102.
If that really is a limitation, catching that earlier (in
sensor_checkedCalc ?) would be helpful.
2) If the f_backend has more than approx. 6000 channels (but I guess
that number depends on the amount of RAM), the setup of the covariance
matrices and the retrieval eat up all memory and take very long. With
atmlab, I could use the 10k channels of our instrument directly. That
was very convenient, but I can work around that. Simon know about this
already, just writing it down again.
Best regards,
Jonas
On 24.09.2018 11:41, Patrick Eriksson wrote:
Hi all, Hi Jonas, Hi Richard,
All: If you do retrievals and using most recent version, you need to
do some small changes. The benefit is that you now also can retrieve
frequency corrections. See the ChangeLog message for a summary.
Jonas: With the commit I just made it should be possible to retrieve a
frequency shift using ARTS's OEM. The demo cfile should be pretty
close to what you want to do. That is, for details see:
controlfiles/artscomponents/oem/TestOEM.arts
I have done some testing, and all looked OK. Tell me if it works for
you or not.
Richard: I also made a small preparation if we ever will test to
retrieve spectroscopic variables. The mapping from the x-vector to
spectroscopic data is planned to be handled by x2artsSpectrosocopy (so
far a dummy WSM)
Bye,
Patrick
On 2018-09-18 15:18, Jonas Hagen wrote:
Dear Patrick
Thanks, of course this would be the proper approach and I hope that
you decide to implement instrument variables soon! This is the last
piece in the way of operational WIRA-C Wind retrievals with ARTS (and
thus without Matlab). Until then I will tinker with my patch.
Best regards,
Jonas
On 18.09.2018 10:27, Patrick Eriksson wrote:
Dear Jonas,
Some quick feedback, I am on a conference.
The variables that you can retrieve using ARTS-OEM so far are mainly
atmospheric quantities. To handle instrument variables I maonly left
for the future.
A constant frequency switch could be handled by shifting the
transitions as you tried to do. But frequency shifts are in fact an
instrument parameter, and moving the transitions will not work for
frequency stretch. So it seems to be time to implement a general way
to handle instrument variables. I will discuss with Simon, that is
also here at the conference.
For the moment I suggest that you do repeated linear inversions. And
adjusting your instrument frequencies after each linear inversion.
This should work with your extension of xaStandard. After some
iterations turn off the frequency switch and make a final inversion.
Kind regards,
Patrick
On 2018-09-17 17:22, Jonas Hagen wrote:
Hello ARTS Developers,
I'm trying to retrieve the Frequnecy Shift along with Wind with the
ARTS internal retrieval. To my understanding, this should work, but
support in xaStandard and x2artsStandard WSMs is missing and
results in an error: "Found a retrieval quantity that is not yet
handled by internal retrievals: Frequency"
For xaStandard(), the a priori Frequency Shift could easily be set
to zero after line 793 of m_oem.cc along with baseline and pointing.
For x2artsStandard(), maybe a new WSV would make sense (f_shift)
and the inversion_iterate_agenda would then call
abs_linesShiftFrequency(f_shift), similar to the baseline stuff?
I tried to implement it myself but got stuck with
jacobian_quantities and indices in x2artsStandard().
Best regards,
Jonas Hagen
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Jonas Hagen
Institute of Applied Physics
University of Bern
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Tel: +41 31 631 5045
#DEFINITIONS: -*-sh-*-
#
# Author: Patrick Eriksson
Arts2 {
INCLUDE "general/general.arts"
INCLUDE "general/continua.arts"
INCLUDE "general/agendas.arts"
INCLUDE "general/planet_earth.arts"
# Agendas to use
#
Copy( abs_xsec_agenda,abs_xsec_agenda__noCIA )
Copy( propmat_clearsky_agenda,propmat_clearsky_agenda__OnTheFly )
Copy( iy_main_agenda, iy_main_agenda__Emission)
Copy( iy_space_agenda,
