Incorrect 1DVAR BA errors?

[Dave Offiler]

Message via Helpdesk & Kent:

> -----Original Message-----

> From: helpdesk@grassaf.org [mailto:helpdesk@grassaf.org]

> Sent: Wednesday, March 03, 2010 2:42 PM

> To: undisclosed-recipients:

> Subject: GRAS SAF Helpdesk Request w.r.t. ROPP Software

> 

> 

> The GRAS SAF Helpdesk has received a question from Pietro Sofi

> 

> The helpdesk subject is:

> 

> ending angle standard error deviations

> 

> The helpdesk description is:

> 

> Dear ROPP team, I would be very grateful for your help on the 

> following problem.

> 

> Wen I give to ropp_1dvar_bangle a COSMIC atmProfile (from

> CDAAC) processed with ucar2ropp colocated with a ECMWF in the 

> ropp-test data (VSDC for obs errors) I get:

> 

> ERROR (from ropp_1dvar_covar_bangle):  Bending angle standard error 

> deviations requested on a per profile basis, but observation data file 

> did not contain sigmas.

> 

> Truly observation sigmas (~10-4) are present and in range ([0 0.01]).

> 

> I substituted, in my oc_20090430211921_c002_g008_ucar.nc

> file, bendings and sigmas from a colocated ropp-test observation file 

> and ropp_1dvar_bangle successfully finished.

> 

> I substituted sigmas only (~10-3) and I got:

> 

> ERROR (from ropp_1dvar_solve):  Initial cost function too high. 

> 

> (Note that i had to fill first the L1 fields in ucar2ropp output, as 

> they were set to missing values, only generic bendings and sigmas were 

> filled).

> 

> What could be wrong?

> 

> Best regards,

> Pietro Sofi

>