Beam Pointing in "Aperture Array" Station type

[rohitcbscient]

We are using OSKAR to inject custom beams using CST file and "aperture array" as station type in the settings. I am reproducing visibility simulation using station type 'Gaussian' and "aperture array" by passing a Gaussian beam from a CST file. We do 2 simulations, one with "Gaussian" station type and the second with "aperture array" with CST file for Gaussian beam. Both simulation is done with tracking mode. I am using oskar_sim_beam_pattern for the beam simulation and generating beam image in the equatorial frame. The station type 'Gaussian' works fine. The size beam is also implemented is fine in the aperture array. However, the pointing direction of the beam is somehow not centred in the given ra,dec position. The direction of beam center is somehow depended on the time of the day and changes in ra mostly. For the station type 'Gaussian' is working perfectly with the correct beam center. The VLA beam also works fine.