A nuclear radiation detector included inside mobile personal communication devices (e.g. cellular or satellite phone, pager, PDA) allows for a network of portable radiation detectors that can not only detect radiation, but also track possible radiation sources by virtue of the ubiquitous nature of such personal communication devices. When radiation levels above a certain level are detected, the detector electronics embedded within any proximate mobile personal communication device communicates with the device to cause transmission of relevant data to the authorities (e.g., central reporting server monitored by FBI). The detection event is assessed by factors including, for example, quantity of alarms in a given area and radiation level detected. The small size of this embedded detector allow for its discreet configuration and monitoring at all times. The device is non-invasive and requires no user knowledge or action, thus eliminating indiscriminate and uncontrolled action by the user.

Radiation detection and tracking with gps-enabled wireless communication system

An apparatus (2) for detecting ferromagnetic objects in the vicinity of a magnetic resonance imaging scanner. The apparatus comprises primary sensor means (4; 44) adapted to measure a magnetic field, arranged in communication with signal processing means configured to identify temporal variations in the measured magnetic field due to the movement of a ferromagnetic object within an ambient magnetic field and to provide an output indicative of the presence of a ferromagnetic object in the vicinity of the primary sensor means (4; 44). The apparatus further comprises secondary, non-magnetic, sensor means (60) adapted to detect the movement of objects in the vicinity of the primary sensor means in order to reduce false alarms. The output from the signal processing means may be used to operate an audible alarm (20), a visual alarm (22), an automatic door lock (26) or a physical barrier (28).

Ferromagnetic object detector

An apparatus for protecting an entrance to a protected area comprises a magnetic sensor to measure an ambient magnetic field or gradient within a first zone of sensitivity at a non-magnetic sensor means adapted to detect the presence of objects within a primary detection zone, a signal processing circuit arranged in communication with the magnetic sensor apparatus and non-magnetic sensor apparatus, and a warning device operable by an output signal from the signal processing circuit, the warning device adapted to provide an alarm. The signal processing circuit identifies temporal variations due to the movement of a ferromagnetic object within the ambient magnetic field and correlates them with instances in which the non-magnetic sensor means detects the presence of an object in its detection zone, and causes the alarm to operate in the event that the correlation is indicative of the presence of a ferromagnetic object in the primary detection zone. It also determines the direction from which an object is approaching the using signals from the non-magnetic sensor means and modifies the operation of the warning device dependent on the direction.

Apparatus for detecting ferromagnetic objects at a protected doorway assembly

Circuitry for detecting magnetic fields includes a first magnetoresistive sensor and a second magnetoresistive sensor configured to form a gradiometer The circuitry includes a digital signal processor and a first feedback loop coupled between the first magnetoresistive sensor and the digital signal processor A second feedback loop which is discrete from the first feedback loop is coupled between the second magnetoresistive sensor and the digital signal processor

Circuitry, systems and methods for detecting magnetic fields

Methods and apparatuses for rejecting radioactive interference in a radiation monitoring station. Techniques typically include two radiation detectors positioned to acquire first and second radiation measurements from a moving radiological source in substantially distinct fields of view. A transition zone is established between the fields of view. A function yielding a dependent variable is defined at least in part by the first radiation level measurement and the second radiation level measurement. A detection alert is generated when the dependent variable reaches the first threshold value. In some embodiments a determination is made as to whether the monitoring station is occupied as a condition for generating a detection alert, and in some embodiments a determination is made as to whether the detected radiological source is likely innocuous or offensive prior to generating a detection alert.

Method and apparatus for rejecting radioactive interference in a radiation monitoring station

A system and method for scanning carriers for objects include the capability to sense a radioactive object in the detection proximity of a platform and form a signal indicative thereof and to determine whether an illicit radioactive object may be in the detection proximity. The system and method also include the capability to sense a metallic object in the detection proximity of the platform and form a signal indicative thereof and to determine whether an illicit metallic object may be in the detection proximity.

Mitchell M. Truitt

Papers

System and method for scanning carriers for objects