1. A method of investigating a sample using charged-particle microscopy, comprising: irradiating a surface of the sample using a probing beam of charged particles in a plurality (N) of measurement sessions, each measurement session having an associated beam parameter (P) value that is chosen from a range of such values and that differs between measurement sessions; and detecting stimulated radiation emitted by the sample during each measurement session, associating a measurand (M) therewith and noting the value of this measurand for each measurement session, thus allowing compilation of a data set (S) of data pairs {P n , M n }, where n is an integer in the range 1≦n≦N, in which a mathematical technique is employed to automatically process the data set (S) in a manner that comprises: defining a Point Spread Function (K) that, for each value of n, has a kernel value K n representing the behavior of the probing beam in a bulk of the sample for beam parameter value P n ; defining a spatial variable (V) that represents a physical property (O) of the sample as a function of position in its bulk; defining an imaging quantity (Q) that, for each value of n, has a value Q n that is a three-dimensional convolution of K n and V, such that Q n =K n *V; for each value of n, computationally determining a minimum divergence 
 min D ( M n ∥K n *V ) between M n and Q n , wherein one solves for V while applying constraints on the values K n .