Patent ID: 8862409

Claim:
A method of measuring the contents of a search volume, the method including: energising one or more transmitters so as to transmit electromagnetic wave energy into the search volume; detecting the effect of the contents of the search volume on the passage of the electromagnetic wave energy by recording two or more signals, each signal being associated with a different propagation path within the search volume; aligning the signals in order to generate two or more aligned signals which are synthetically focused on a desired voxel in the search volume, each aligned signal being associated with a different propagation path within the search volume; calculating a quality factor by processing the aligned signals to generate two or more data values, and processing the data values to generate the quality factor, the quality factor being indicative of a degree of coherence in the aligned signals; summing the aligned signals to generate a summed signal; and processing the summed signal to generate an output which is indicative of the contents of the search volume at the location of the desired voxel, the output varying in accordance with the quality factor.