This paper discusses the advantages of both geometry of data required for the reconstruction algorithm, orthogonal polynomial expansion on disc (OPED), and polynomial structure of this algorithm. We show that this type of geometry is a result of special parameterisation used within the OPED formalism. The practicability of the OPED data geometry is discussed and it is shown that the data of such geometry can be acquired directly. A method of reducing typical artefacts by using the polynomial structure of the algorithm is summarised as well.