  Full polarimetric radio interferometric calibration is performed by
estimating 2 by 2 Jones matrices representing instrumental and propagation
effects. The solutions obtained in this way differ from the true solutions by a
2 by 2 unitary matrix ambiguity. This ambiguity is common to all stations for
which a solution is obtained but it is different for solutions obtained at
different time and frequency intervals. Therefore, straightforward
interpolation of solutions obtained at different time and frequency intervals
is not possible. In this paper, we propose to use the theory of quotient
manifolds for obtaining correct interpolants that are immune to unitary matrix
ambiguities.
