Continuous variable tomographic measurements

Using a recent result of Albini et al. [P. Albini, E. De Vito, A. Toigo, J. Phys. A: Math. Theor. 42 (2009) 295302] to represent quantum homodyne tomography in terms of a single observable (as a normalized positive operator measure) we construct a generalized Markov kernel which transforms the measurement outcome statistics of this observable into the measurement outcome statistics of a covariant phase space observable. We also consider the inverse question. Finally, we add some remarks on the quantum theoretical justification of the experimental implementations of these observables in terms of balanced homodyne and 8-port detection techniques, respectively.