Hi George, Thank you for your answer !
I followed the qpack2_wind3d_demo and I managed to run the retrieval with two angles. There is just something that I don't understand. I defined the different angles in Y.ZA. But apparently we don't have to put the list of angles in q_demo in the variable Q.MBLOCK_ZA_GRID. In the qpack2_wind3d_demo, there is only one value equal to zero in Q.MBLOCK_ZA_GRID.. When I tried to copy in Q.MBLOCK_ZA_GRID the same list of angles as in Y.ZA I had an error so I assumed we have to let 0 in Q.MBLOCK_ZA_GRID. Can anybody confirm ? Thank you very much. Best regards, Pauline ----- Météo-France ----- Dr. Pauline Martinet Chercheur CNRM/GMEI/LISA [email protected] Fixe : +33 561079031 Site web: https://sites.google.com/site/martinetpauline31/ ----- Mail original ----- De: "George P. Ford" <[email protected]> À: "MARTINET Pauline" <[email protected]>, [email protected] Envoyé: Mardi 9 Septembre 2014 11:53:47 Objet: RE: retrieval of humidity profiles with qpack and multi viewing angles Re. Your first issue, I’ve been using the qpack2_wind3d_demo which already has multiple viewing angles – you could probably modify it for your purposes, or it would at least be a good reference. It appears it appends each spectrum on to the end of the Y vector, rather than creating a new column, hence avoiding the tensor1 issue. From: MARTINET Pauline [mailto:[email protected]] Sent: 09 September 2014 10:30 To: [email protected] Subject: [Qpack] retrieval of humidity profiles with qpack and multi viewing angles Dear all, I have some issues to run humidity profile retrievals with qpack and also to run the retrieval with different viewing angle. I am using the observations from a ground based microwave radiometer with 7 channels and 8 viewing angles. I ) Problem with different viewing angles Fistly, I managed to retrieve temperature profiles with qpack but only with one viewing angle. I use a matlab program similar to the qpack_demo.m file. So I modify the q_demo routine to include a second angle in Q.MBLOCK_ZA_GRID ( for example Q.MBLOCK_ZA_GRID= [0 48] instead of 0). I also create the structure Y with a function similar to the y_demo function in the qpack_demo.m file. After creating the Y structure, I copy the brightness temperature observed by the instrument in the Y(1).Y field: Y(1).Y=TB_mesure but this time the size of the array TB_mesure is : 2 * 7 instead of 1* 7 (so 2 angles and 7 channels). When I add this line, I have the error message: Error using rqre_datatype (line 68) Y(1).Y must be tensor1. Error in qpack2>checkY (line 154) rqre_datatype( Y(1).Y, @istensor1, 'Y(1).Y' ); Error in qpack2 (line 52) empty_y = checkY( Y ); I assume this comes from the fact that there are two dimensions instead of 1 due to the addition of the new viewing angle. Does anyone know how we can run a retrieval with multiple viewing angles ? By the way, does the variable Y.ZA refers to the wiewing angles like Q.MBLOCK_ZA_GRID ? (I tried to modifiy this variable to include the second angle also.) II) Problem with the humidity retrieval In my ARTS simulations, I use a humidity profile directly read from a background profile (thus it is not a profile given with the atmlab package). When I declare the water vapor species in the q_demo file: Q.ABS_SPECIES(2).TAG = {'H2O-PWR98'}; Q.ABS_SPECIES(2).RETRIEVE = false; If Q.ABS_SPECIES(2).RETRIEVE is false, I have no problem during the computation of the temperature retrieval (even if I use my own humidity profile for the simulation of the brightness temperature). Then, when I try to retrieve the humidity profile in addition to the temperature profile, I changed the Q.ABS_SPECIES(2).RETRIEVE variable to true, and I have the following error: Run-time error in controlfile: /tmp/atmlab-martinet-tp9a5f653c_5510_4107_adc5_2463807d555b/cfile_y.arts Run-time error in method: atmfields_checkedCalc All values in *vmr_field* must be >= 0. Stopping ARTS execution. Goodbye . However, I checked the vmr_field of the Q.ABS_SPECIES(2).ATMDATA.GRID and all the values look higher than 0 (see attached file) and I already used this humidity profile even if I did not retrieve the humidity without no problem in ARTS. Thus, I don't really understand why I have this error. Does anyone have on idea ? Thank you very much for your help. Best regards, Pauline ----- Météo-France ----- Dr. Pauline Martinet Chercheur CNRM/GMEI/LISA [email protected] Fixe : +33 561079031 Site web: https://sites.google.com/site/martinetpauline31/ 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.
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