Abstract: An imaging system (1) comprises a transmitter (3, 6), a receiver (3, 4, 6), an antenna array (2); and a controller (4, 5, 10, 11) for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object. The controller has multiple distributed processors (15) to calculate antenna control pattern data during run-time. The processor (4, 5) assesses misalignment of antennae using a receiver placed in the imaging volume, and monitors level of energy received by the receiver and compares it with a reference energy level. Also, the controller performs on-the-fly modification of antenna control pattern data according to real time conditions such as mechanical misalignment of the transmitter, the receiver, or of one or more antennas. The controller may generate three-dimensional offset vectors to provide a profile of the offset across the scan volume, and the position of an antenna may be moved to compensate for the mechanical misalignment.

Abstract: An imaging system comprises a transmitter (24, 25), a receiver (24, 25, 21), and a controller (20) for directing the transmitter and the receiver to scan an object in a volume. The controller determines which sub-volumes of the volume the object is located within and then performs a fine scan in those sub-volumes. This reduces overall scanning time. The controller (20) may compare a received signal sample magnitude from the initial scan with a threshold to make the decision. The initial scan may be performed with a spot size to include only one or more particular volume elements within at least some of the sub-volumes.

Abstract: An imaging system (1) comprises a transmitter (3, 6), a receiver (3, 4, 6), an antenna array (2); and a controller (4, 5, 10, 11) for directing the transmitter, the receiver, and the antenna array to scan a volume containing an object. The controller has multiple distributed processors (15) to calculate antenna control pattern data during rim-time. The processor (4, 5) assesses misalignment of antennae using a receiver placed in the imaging volume, and monitors level of energy received by the receiver and compares it with a reference energy level. Also, the controller performs on-the-fly modification of antenna control pattern data according to real time conditions such as mechanical misalignment of the transmitter, the receiver, or of one or more antennas. The controller may generate three-dimensional offset vectors to provide a profile of the offset across the scan volume, and the position of an antenna may be moved to compensate for the mechanical misalignment.

Abstract: Electrical properties of concealed dielectric objects, such as the dielectric permittivity, can be deduced from incident, reflected, and transmitted electromagnetic waves in an imaging system. In a confocal arrangement a horn illuminates a reflect array and the reflect array is configured to focus the radiation at an element in the scan volume. The reflections are in turn refocused by a reflect array at the horn aperture. The reflect array is electronically configured to scan the focal point throughout the scan volume in a systematic way. Knowledge of the horn pattern and the scan strategy allows the system to compute the geometry associated with each volume element. Amplitude and phase variations between the object and the surrounding volume and the computed geometry are used to estimate the relative permittivity and thus facilitate categorization of the object using a database of material relative permittivities.

Abstract: An imaging system comprises a transmitter (24, 25), a receiver (24, 25, 21), and a controller (20) for directing the transmitter and the receiver to scan an object in a volume. The controller determines which sub-volumes of the volume the object is located within and then performs a fine scan in those sub-volumes. This reduces overall scanning time. The controller (20) may compare a received signal sample magnitude from the initial scan with a threshold to make the decision. The initial scan may be performed with a spot size to include only one or more particular volume elements within at least some of the sub-volumes.

Abstract: Electrical properties of concealed dielectric objects, such as the dielectric permittivity, can be deduced from incident, reflected, and transmitted electromagnetic waves in an imaging system. In a confocal arrangement a horn illuminates a reflect array and the reflect array is configured to focus the radiation at an element in the scan volume. The reflections are in turn refocused by a reflect array at the horn aperture. The reflect array is electronically configured to scan the focal point throughout the scan volume in a systematic way. Knowledge of the horn pattern and the scan strategy allows the system to compute the geometry associated with each volume element. Amplitude and phase variations between the object and the surrounding volume and the computed geometry are used to estimate the relative permittivity and thus facilitate categorization of the object using a database of material relative permittivities.