Ad Hoc Wireless Sensor Tomography

This paper proposes a new "tomographic" paradigm involving ad hoc wireless sensor networks that are hosted in a process vessel. The sensors, which may be numerous are, ideally, neutrally buoyant, free to move with the flow in the vessel and can determine their position in three dimensions. The challenge is to determine the distribution of materials in the vessel from local measurements on each sensor, married with a knowledge of the behaviour of an energizing field. Determination of position and selection of tomographic measurement modality will be influenced by the nature of the process. Appropriate techniques might include electrical, acoustic or optical excitation. Data might be stored by embedded processors in the sensors for subsequent, off-line, processing or alternatively might be communicated by wireless means for on-line processing. Progress to date has been informed by the results of efforts to realize process compliant 3D tomographic imaging which seeks to exploit mobile electrodes that are attached to vessel "furniture".