Abstract: Some systems include an illuminator configured to illuminate a scene, a detector configured to receive electromagnetic radiation from the scene, one or more retroreflective tags, and an image processor. Each of the one or more retroreflective tags is attached to or positioned near a corresponding target and is configured to reflect electromagnetic radiation from the illuminator toward the detector. The image processor can identify electromagnetic radiation reflected by one or more retroreflective tags to determine the presence of one or more retroreflective tags and corresponding targets in the scene. Retroreflective tags can include retroreflective portions and non-retroreflective portions such that, when electromagnetic radiation is incident upon the retroreflective tag, the retroreflective tag reflects the electromagnetic radiation in a pattern that corresponds to a code uniquely corresponding to the target.

Abstract: Systems for detecting occupancy of an area comprising one or more zones can include one or more sensors and one or more processors configured to receive sensor data from the one or more sensors over time. The one or more processors can be further configured to receive or store data about an arrangement of the zones in the area. The one or more processors can apply a probabilistic model considering the sensor data received over time to determine the number of subjects in each zone by determining a most likely current state of occupancy of the area among a plurality of possible scenarios.

Abstract: A method of determining information relating to the occupancy of a space that includes receiving first data relating to the occupancy of the space over a time period, receiving second data indicative of either times of decrementing events or times of incrementing events affecting the occupancy of the space during the time period, and either, for each decrementing event time, using the first data to obtain an estimated incrementing event time, or, for each incrementing event time, using the first data to obtain an estimated decrementing event time. The method has particular application in the determination of waiting times, for example in the context of queue monitoring.

Abstract: A queue monitoring system for monitoring persons queuing to use electronic transaction apparatus, wherein the apparatus comprises at least one user interface, the system comprising one or more cameras for providing data relating to persons queuing and processing apparatus configured to process the data to determine one or more parameters of the queue, wherein the processing apparatus is additionally configured to receive from the electronic apparatus information that is conveyed to the user interface and to use this information in processing the data.

Abstract: Using a processor to receive a signal indicative of actuation of a cleansing product dispenser at a hand cleansing station and to receive a signal indicative of the presence of an individual at said cleansing station following actuation of the cleansing product dispenser. The processor is configured to process said signals to generate hand wash event data indicative of a length of a continuous period of time spent by said individual at said hand cleansing station. Hand wash event data is collated for a plurality of hand wash events at a stand-alone hand cleansing station or a plurality of linked hand cleansing stations in order to provide an indication of hand wash quality for said plurality of hand wash events and/or an indication of a number of compliant hand wash events. A running total of compliant hand wash events may be displayed to users.

Abstract: A system for monitoring the motion of objects is configured to identify objects meeting predetermined criteria appearing in a scene and to track the motion of identified objects across the scene. In a particular embodiment the system is configured to compile statistical data for multiple points or regions to indicate one or both of: the frequency with which objects are initialised at that region or point; and the frequency with which initialised objects cross the region or point. The initialisation data will indicate the areas in the scene where objects are most frequently initialised. If the statistical data shows an area of the scene in which objects are never initialised this might indicate that there is an obstruction between objects that need to be tracked and the detector. The path data will indicate the paths most frequently followed by objects.

Abstract: A queue management system for e.g. supermarket checkouts uses counting devices located at checkouts and optimally entrances/exits in conjunction with P.O.S. information to produce a schedule of how many checkouts are needed to avoid queue length exceeding preset limits. The system includes a dynamic learning system which can optimize calculated schedules on the basis of historical data.

Abstract: A queue management system for e.g. supermarket checkouts uses counting devices located at checkouts and optimally entrances/exits in conjunction with P.O.S. information to produce a schedule of how many checkouts are needed to avoid queue length exceeding preset limits. The system includes a dynamic learning system which can optimise calculated schedules on the basis of historical data.

Abstract: A surveillance system using an array of detectors onto which energy from the scene under surveillance is focused can indicate the direction of an event that has been recognized. The invention uses two or more arrays to locate events in three dimensions, and to define regions within the three dimensional space being surveyed. The events are located by detecting which elements from the respective arrays are stimulated by the occurrence of an event, and determining the location of the event to be at the intersection of the fields of view of the stimulated elements.

Abstract: An optical detection system for forming an image of a field of view in an object plane onto an image plane in which the electromagnetic radiation image is transmitted to a detector array at the image plane via an optical distorting element such as a reflector 11, so as to impose a non linear relationship between areas in the image and object planes.

Abstract: A method of testing resistance bolometer arrays involves applying different voltages to different bolometers so as to produce a detectable difference between adjacent bolometers under normal conditions. The voltages may be applied in a recognizable pattern so that faults can be readily identified from a visual display of the array.

Abstract: A method of identifying the presence of turbulence in fluids, e.g. for distinguishing flames from other hot bodies, examines the correlation between adjacent pixels of an array viewing the fluid and particularly the proportion of negative correlation in the presence of strong positive correlation.

Abstract: A radiation detection apparatus is capable of detecting and locating events, such as a fire or the appearance of an intruder, in a scene under surveillance. The apparatus comprises an array of detector elements, e.g. infrared detectors. The apparatus has two fields of view, namely a first field of view defined by a lens providing a single focussed image of a distant scene on the array and a second field of view defined by a reflector arranged between a plane of the array and a plane of the lens whereby to reflect onto the detector array radiation entering the lens from outside the first field of view. One or more processors are provided to distinguish events in the second field of view from those in the first field of view.

Abstract: A two dimensional array of resistive bolometers (B) is arranged in rows and columns. Amplifiers (A0, A1 etc) amplify signals obtained from the bolometers. Instead of providing one amplifier per column, a smaller number of amplifiers is used each of which is connected to a plurality of column sense lines (L) via a multiplexer (M0, M1 etc).

Abstract: A two dimensional array of resistive bolometers (B) is arranged in rows and columns. Amplifiers (A0, A1 etc) amplify signals obtained from the bolometers. Instead of providing one amplifier per column, a smaller number of amplifiers is used each of which is connected to a plurality of column sense lines (L) via a multiplexer (M0, M1 etc).

Abstract: A two dimensional array of resistive bolometers (B) is arranged in rows and columns. Amplifiers (A0, A1 etc) amplify signals obtained from the bolometers. Instead of providing one amplifier per column, a smaller number of amplifiers is used each of which is connected to a plurality of column sense lines (L) via a multiplexer (M0, M1 etc).

Abstract: Arrays of pyroelectric elements are used in surveillance systems by focusing the radiation from a scene on to them and examining the output from the array. If an object is moved into the scene and left stationary, it will hinder the subsequent operation of the system by masking part of the scene from the field of view of the array; this fault condition may be detected by the following procedure. At intervals arrangements are made to move the image of the scene to and from across the array using a suitable transducer and the outputs from the array are examined. The outputs from the array when the scene is in its normal condition and the image is moved across the array comprise a set of signals corresponding to a reference image, which may be compared with the corresponding outputs from the array when the image is moved across the array on a subsequent occasion.

Abstract: A turbulent fluid, such as a flame, is examined using an array of infrared detector elements. The relationship between the thermal emissions received by different elements at different times is analysed, for example using correlation functions. This enables existence of a flame to be verified and the nature of the flame to be identified.

Abstract: A signal processing technique applied to the readout of two-dimensional detector arrays provides a dynamic correction mechanism for the varying offsets of the different elements of the array. The outputs of the elements are supplied to an offset correction circuit operative to compensate for the differences in the d.c. or low frequency outputs from a predetermined voltage wherein a fraction of the difference is subtracted at each successive cycle to gradually reduce the difference.

Abstract: A method and apparatus for an event detector using an array of passive infrared detector elements, which uses interchangeable spectral filters and lenses to permit detection of a range of event types, which normally each require individual detectors with specific spectral/optical designs.