id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
219	Lower BA range in BUFR?	Dave Offiler	Dave Offiler	"The BUFR template document defines the BA descriptor with an offset and bit width which is capable of holding a minimum BA value of '''-10**-3''' rad. However the current trunk code ''ropp2bufr.f90'' has a hard-coded check limit of '''-10**-4'''.

The default ROPP value (in ''ropp_io_types.f90'') is -10**-3, (though there is not 100% correlation between internal ROPP and BUFR range limit values (mostly due to limitations of the BUFR format).

Since this document & code and ranges in general have been reviewed several times since ROPP was first released, there must have been some good reason why the coded value is different from the template (though I have no recollection now what that reason might have been!) The -10**-4 value is certainly a safe option.

Stig reports that DMI have changed the coded value to -10**-3 with no ill effects (is this used operationally?)

I've changed the coded value in trunk version of ''ropp2bufr.f90'' to '''-10**-3''', re-built the executable and tested with the ''tests/t_ropp2bufr script''. This shows a '''PASS''', with no differences in the BUFR file from the reference file created with the previous (-10**-4) version. This merely says that there are no BA values in the test file within the range -10**-3 to -10**-4, so this is not a rigorous test of the change.

Leaving this ticket open until it is confirmed that the change has no bad effects within ''ropp2bufr'' itself, ''bufr2ropp'' or any other tool, using at least one input file with appropriately low BA values. "	defect	closed	minor	5.0	ropp_io	4.1	fixed	BUFR, range, BA, bending angle	ssy@…