A320 NAV discrepancy
 

as the nav mode engaged after takeoff i noticed a difference on the 1 FD 2 roll command.
Went on to compare the NDs to note a 0.4nm off track difference indicated (left ND centered right ND Off track).

GPS PRIMARY,

NAV accuracy high,

and NAV accuracy check = one degree off on the VOR needles vs fix bearing on progress page.

DME = to fix distance.

what is happening here? how to go about it?

is this supposed to happen in GPS primary ?

isn't the Kalman filter supposed to smooth out these things on our Litton referenced FMGS2?

thanks in advance you for your input.

In your case, AP1 was engaged. That means FMGC1 was master so the FDs were centred on the left side. FMGC2 was disagreeing a little bit which is why the FD needles on the right were different to those on the left. If you had engaged AP2, the aircraft would have followed the FDs on the right side.