Opportunities for data fusion in multi-modality tomography

It is now possible to fit several tomographic systems to an industrial process. By the use of different modalities to image the process, the process engineer can plan to take advantage of the strongest features provided by each unit. Detailed information from different modalities might be gained by inspection of separate tomograms. To maximise the information available from the combined tomographic system however data fusion is clearly the better option. A combined tomogram can be produced of superior quality to any of the separate tomograms: the sum can be better than the parts. Fusion might be achieved at different levels. Greater accuracy may be achieved by fusion at the measurement level, but at the expense of centralised processing. An example is given for a hydrocyclone where data from an electrical resistance tomograph and a reflective-mode ultrasound tomograph are fused. A discussion of issues relevant for fusion in process tomography is given.