Hi all, Just made a commit with two changes that affect Qpack. One extension, and one that could require a small modification.
1. For both theoretical and practical reasons, I have changed the L2 output for ABS_SPECIES to follow the selected retrieval unit. This affects the rel and logrel options. The output was before converted automatically to VMR. This conversion is now moved to the function qp2_rel2vmr. The theoretical justification is to return data that are fully consistent with the assumptions of the retrieval. This point is most critical for the logrel case, where the returned data theoretically have a normal distribution while converted to VMR it would be log-normal. However, using logrel can cause substaintail non-linearity in the retrieval problem and it is likely that the errora not follow normal distributions. 2. The setting ABS_SPECIES.L2_RANGE is introduced, that allows to fine-tune L2 data. This simplifies to make use of the fact that retrieved profiles are treated as constant outside the end points. For example, with rel you can retrieve a constant relative change of the profile above some pressure (which then should be the minimum pressure of the retrieval grid). See further qinfo(@qarts,'ABS_SPECIES') Bye, Patrick -------- Original Message -------- Subject: [s-c-rt] r6966 - in atmlab/trunk: . arts geophysics retrieval/qpack2 Date: Sun, 22 May 2011 15:54:12 +0200 From: [email protected] <[email protected]> To: [email protected] <[email protected]> * atmlab-1-0-129 * Important for Qpack users. L2 output for ABS_SPECIES now follows the selected unit strictly. More information in qpack2.pdf and email to qpack mailing list. * retrieval/qpack2/qpack2.tex: Modified to reflect changes below. The information for L2 'ptz' was old. * retrieval/qpack2/qp2_rel2vmr.m: Created. * arts/arts_regrid.m (extract_grids): Introduced qname, to improve error message. * arts/qarts.m (qarts): Added L2_RANGE as sub-field to ABS_SPECIES and T. * retrieval/qpack2/qp2_l2.m (qp2_l2): For absorption species, the conversion to VMR for 'rel' and 'logrel' is removed. That is, the output follwos now throughout the retrieval unit. This is also the case for errors estimates. Added handling of L2_RANGE (and this part of the function revised). * arts/arts_x2QR.m (arts_x2QR): "Extrapolation" was done for VMR independently of retrieval unit selected. This follows now the retrieval unit. For example, if "rel" is selected and the end value is 1.1, the VMRs on this side of the grid are scaled with 1.1. Before the end VMR value was used out to the atmospheric limit. * arts/arts_oem_init.m (arts_oem_init): Improved header. Revised the set of variables that are stored as part of R. * geophysics/nd2vmr.m: Spelling mistake in header. _______________________________________________ qpack mailing list [email protected] https://www.sat.ltu.se/mailman/listinfo/qpack
