Ionospheric Delay: Calculated or Estimated?

[Jim Frame]

On the SurveyorConnect site today, Trah posted this in response to a question of mine:

The most problematic error source for single baseline RTK outside the user's control is still the troposphere (particularly if you base station and rover are at significantly different elevations) and the ionosphere. Although we can remove the ionosphere using dual frequency receivers, most RTK algorithms don't do this as it makes ambiguity resolution very difficult. Instead the ionosphere is estimated, which can be tricky if the ionosphere is behaving unexpectedly.

Can anyone tell me how J-Field handles iono delay?

Thanks!

 

[Jim Frame]

I have no idea how that screenshot got attached to my post. I had looked at that message because I couldn't recall how to tag a quote, and somehow it came along for the ride. Please ignore it.

 

[Matt Johnson]

I am pretty sure it is removed. From Javad's Tutorial on Fundamentals of GPS:

 

[Jim Frame]

I am pretty sure it is removed.

Removed, yes, but whether by modeling or calculation is the question. The referenced tutorial isn't specific as to the processing method, but I get the impression that it's referring to post-processed vectors. As far as I know, all post-processors calculate the delay. In my mind, the question remains open: does J-Field calculate the delay for RTK solutions?