Dear Patrick, Thanks I have run qarts_demo2 and managed to extract transmission using the following process:
[y,y_aux] = arts_y( Q ); array = cell2mat(y_aux) transmission = exp(-array) I think I can transfer everything I had in my qpack2 code to qarts. Best wishes Emma ________________________________________ From: Patrick Eriksson [[email protected]] Sent: 27 November 2014 15:24 To: Turner, Emma C. Cc: [email protected] Subject: Re: [Qpack] Obtaining Y units of Transmission from q_pack Hi Emma, No problem, I understand that this is far from obvious. In short, qarts is an attempt to make a relatively general interface to ARTS. What you can do with qpack2 is more restricted, but tries to streamline the retrieval procedure. In a way, qpack2 is sub-set of qarts where some things happen "automatically". There are some comments in the qpack2 pdf document. Anyhow, for how to use qarts (without doing retrievals), see e.g. qarts_demo2 in the demos folder. You will recognise the Q structure. And to run arts there are some different functions depending on what you want to do, but arts_y is by far the most important one. That is, [y,y_aux] = arts_y( Q ); is matlab code. If you have set up a Q to be used with qpack2, you need to make some modifications. At least you need to set SENSOR_POS and SENSOR_LOS. The rest depends on how you have set VMRs etc. in Q. Sorry, can not give you a complete answer there. The best help is the demo scripts in /demos. Note e.g. that arts_y is used in qpack2_demo to generate a test measurement, to be inverted. Bye, Patrick On 2014-11-27 15:51, Turner, Emma C. wrote: > Hi Patrick, > > Apologies for my ignorance but what is the more general qarts system? > Does that mean applying the below code snippet in the arts C++ code? > > Thanks Emma ________________________________________ From: Patrick > Eriksson [[email protected]] Sent: 27 November 2014 14:33 > To: Turner, Emma C. Cc: [email protected] Subject: Re: [Qpack] > Obtaining Y units of Transmission from q_pack > > Hi Emma, > > CC to qpack list as this is of general interest. And we prefer if > all questions go to any of the arts and qpack lists. > > The answer is: > > [y,y_aux] = arts_y( Q ); > > > There is now way to obtain the aux vars by qpack2. If you want this > information you must use the more general qarts system, where then > arts_y is the function to use. Or, of course, using arts directly. > > Bye, > > Parick > > > > > On 2014-11-27 15:07, Turner, Emma C. wrote: >> Thanks Patrick, >> >> It runs now, how do I extract the data for tau from Y? >> >> Bye, Emma ________________________________________ From: Patrick >> Eriksson [[email protected]] Sent: 27 November 2014 >> 13:50 To: Turner, Emma C.; [email protected] Subject: Re: >> [Qpack] Obtaining Y units of Transmission from q_pack >> >> Dear Emma, >> >> Uuups, a piece of documentation that has not been updated. I will >> fix that. >> >> I assume you use iyEmissionStandard, then you can check out the aux >> var options by >> >> arts -d iyEmissionStandard >> >> That is, the option is >> >> Q.IY_AUX_VARS = { 'Optical depth' }; >> >> that gives you tau, which you easiliy can covert to transmission. >> >> Bye, >> >> Patrick >> >> >> On 2014-11-27 14:43, Turner, Emma C. wrote: >>> Dear mailing list, >>> >>> Using the ARTS forward model to simulate a ground-based sensor I >>> am looking to obtain total Transmission values (in %) in addition >>> to Brightness Temperature values. ARTS leads me to believe I can >>> do this using iy_aux_vars where in the documentation it states >>> that "Transmission, total" is a valid option when I use ycalc - >>> http://www.sat.ltu.se/arts/docserver-stable/variables/iy_aux_vars >>> >>> >>> I'm having trouble with the syntax in q_pack2, when I include >>> >>> Q.IY_UNIT = 'PlanckBT'; Q.YCALC_WSMS = { >>> 'yCalc' }; Q.IY_AUX_VARS = { 'Transmission' } >>> >>> to the code it complains that, 'For calculations using yCalc, >>> *iy_aux_vars* can not include variables of along-the-path or >>> extinction matrix type.' but when I add 'Total' like it suggests >>> in the documentation >>> >>> Q.IY_AUX_VARS = { 'Transmission', 'Total' } >>> >>> it complains that, 'In *iy_aux_vars* you have included: "Total". >>> This choice is not recognized.' >>> >>> Can someone help me? >>> >>> Many thanks Emma >>> >>> This message (and any attachments) is for the recipient only. >>> NERC is subject to the Freedom of Information Act 2000 and the >>> contents of this email and any reply you make may be disclosed by >>> NERC unless it is exempt from release under the Act. Any material >>> supplied to NERC may be stored in an electronic records >>> management system. >>> _______________________________________________ qpack mailing >>> list [email protected] >>> https://www.sat.ltu.se/mailman/listinfo/qpack >>> >> >> This message (and any attachments) is for the recipient only. NERC >> is subject to the Freedom of Information Act 2000 and the contents >> of this email and any reply you make may be disclosed by NERC >> unless it is exempt from release under the Act. Any material >> supplied to NERC may be stored in an electronic records management >> system. >> > > This message (and any attachments) is for the recipient only. NERC is > subject to the Freedom of Information Act 2000 and the contents of > this email and any reply you make may be disclosed by NERC unless it > is exempt from release under the Act. Any material supplied to NERC > may be stored in an electronic records management system. > This message (and any attachments) is for the recipient only. NERC is subject to the Freedom of Information Act 2000 and the contents of this email and any reply you make may be disclosed by NERC unless it is exempt from release under the Act. Any material supplied to NERC may be stored in an electronic records management system. _______________________________________________ qpack mailing list [email protected] https://www.sat.ltu.se/mailman/listinfo/qpack
