Abstract: A method is provided for constructing a tomographic reconstruction through the application of statistical inversion. Unknowns associated with points of a reconstruction grid are represented with components of a vector-valued variable. A next version of the vector-valued variable is repeatedly created by drawing for each component a value from a conditional distribution. The components of a so generated version of the vector-valued variable are used as the tomographic reconstruction. The components are divided into sets, so that components in a set represent unknowns associated with mutually independent points of the reconstruction grid, or into independent collections. For at least two components of a set or at least two collections, the drawing of values from a conditional distribution is performed in parallel in a computer-implemented process.

Abstract: A method and an arrangement are provided for producing a computed distribution of speeds of scatterers in a target volume (1701). An estimate distribution of speeds at which scatterers would move in the target volume is provided (1201). It is converted (1202) to a candidate autocorrelation function that represent autocorrelation data points that a pulse radar would measure from the current estimate distribution. The fit of a candidate ACF to a measured ACF is measured (1203). The estimate distribution is accepted if a measured fit fulfils a predefined acceptance criterion, or modified (1205) in which case processing returns to the conversion of the modified estimate distribution to an ACF. An accepted estimate distribution is output (1206) as a computed distribution of speeds that describes the actual distribution of speeds.