Quantum tomography as normalization of incompatible observations

Synthesis of incompatible observations - a reconstruction of quantum state - is formulated consistently with quantum theory using the maximum likelihood estimation. Solving the nonlinear multidimensional equation for the density matrix is equivalent to finding the probability operator measure, whose expectation values are measured frequencies, and which provides the decomposition of an identity operator. (C) 1999 Published by Elsevier Science B.V. All rights reserved.