id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
692	Improve navigation bits documentation in ROPP PP user guide	Ian Culverwell	Ian Culverwell	"ROPP-10 DRR reviewer Riccardo Notarpietro complains that
{{{
The Navbit handling is not clear (to me). There is no theoretical description
associated to the interpolation/removal of the navbit.

p30: Not clear what the ""lost carrier flag profile variable"" is. It should be a
variable containing the navbit. Is this included in some input file? Is it time
stamped? It seems that navbits are interpolated somewhere before making this
bitwise variable available. Which is the module which takes care of this?

p30: What are these ""alternative navigation bits""? Who provides these?

p30: it is written ""If available, excess phase data navigation bits may be read
from a separate text file (path specified by the navbit file config option),
which contains a sequence of two-digit binary value navigation bits as a
function of GNSS time. These bits are interpolated to the occultation
measurement times and stored as variable LCF"". Not clear how they are used. Two
digits? Why? Then for GRAS, Navbits are available in a predefined format (ascii,
with one subframe / GNSS epoch encoded into a string of exadecimals when they
were provided by GSN, NeCDF with again one subframe / GNSS epoch, encoded into
an array of integers).

p30: Eq. 4.3-4.5: .... not clear. If you have external bit available, you should
use it directly correcting the I,Q residual phase. At least this is dobe in the
EUM processing.

p 24: -navfile option. It is stated that the default is to use th e internal
correction. What does it mean? How it works?
}}}

At the ROPP-10 DRR we agreed to tidy this up a bit for ROPP-10, but to return to it in earnest at ROPP-11.0."	task	closed	normal	11.0	ropp_pp	10.0	fixed