>1- Is it worth implementing the 'baseline' code in ROPP? Or rather we make one
>re-planning the WP iono in order to focus only on the advanced?
>(this would be: A-fix discontinuity problem, B-help the implementation in ROPP (TBD with Ian), C-generate documentation necessary, D-prepare any of the 'reviews' if there is time)
>

Taking into account the delay in the EPSG mission launch, and the present major health problems in the IEEC-team, 
we suggest to focus from second mid of September on the advanced approach, following for instance the suggested A-B-C-D working plan.

>
>2- how much time do you think you need to fix the issue
>discontinuity? do you think it is a 'bug' or will the algorithm need to be changed in >Yes? I guess it’s not something you can do before fall, is it?
>

This problem, when it happens, is likely related to the way of solving the non-linear system of equations, without background model, 
including the connection between both parts of each radio-occultation event: bottom (directly observed, modeled under Abel approach) 
and top (extrapolated adjusting a linearly increasing scale height Chapman model) parts of the radio-occultation event, 
specially in some cases when the electron density height is very high (e.g. above 380 km). We will do our best to provide a fixation 
to this occasional discontinuity before fall (by mid of September), and in any case by the end of 2020.

>
>3- If it's a 'bug' or a non-major change in the algorithm, maybe Ian
>could start implementing in ROPP the advanced algorithm, at least the
>parts or routines that are not affected by the problem
>discontinuity. Is it like that? or the prototype as such is not mature enough for
>start thinking about implementing in ROPP?
>

Yes, starting on end of September a prototype of the ionospheric preprocesor might be started (making available for the next programs within ROPP "ecosystem": 
the date, transmitter and receiver Ids., elevation above the local LEO horizon, receiver position, transmitter position, L1-L2 in length units).


>
>4- in case Haixia was off for a long time, do you think
>could you progress in activities A, B, ... listed in point 1?
>

Good question. If Haixia is off let's say one month or less after September, yes I could work on her behalf during such time. 
Otherwise other solutions should be looked for (for instance, I could extend my work on behalf of Haixia), likely with some associated delays (TBD).


>If you can think of these questions in order to give answers on day 1
>of July, it would be better in order to make a meeting more effective and arrive
>to conclusions about what Ian should do, etc. (and also how we approach the
>CDOP4, of course, but CDOP4 is not a July 1 issue).


Sure. Inputs to potential contributions to CDOP-4 are given in next dedicated file.