A device may receive radio frequency (RF) transmissions from access points provided in a zone, and may calculate channel state information (CSI) for the access points based on the RF transmissions. The device may identify CSI phases that satisfy a phase threshold to eliminate surrounding movement in the zone and to focus on an entry location of the zone, and may perform a short-time Fourier transform of the CSI phases to generate a frequency versus time graph. The device may perform a spectrogram analysis of the frequency versus time graph or may process the frequency versus time graph, with a machine learning model, to determine a quantity of people in the zone and a start and stop times associated with entries and exits of the people to and from the zone. The device may perform actions based on the quantity of people and the start and stop times.

A device may receive radio frequency (RF) transmissions from access points provided in a zone, and may calculate channel state information (CSI) for the access points based on the RF transmissions. The device may identify CSI phases that satisfy a phase threshold to eliminate surrounding movement in the zone and to focus on an entry location of the zone, and may perform a short-time Fourier transform of the CSI phases to generate a frequency versus time graph. The device may perform a spectrogram analysis of the frequency versus time graph or may process the frequency versus time graph, with a machine learning model, to determine a quantity of people in the zone and a start and stop times associated with entries and exits of the people to and from the zone. The device may perform actions based on the quantity of people and the start and stop times.

A system, including: a radar including a transmitter and a receiver, the transmitter configured to transmit an electromagnetic wave; a reflector placed a predetermined distance away from the radar, the reflector configured to reflect the transmitted electromagnetic wave back to the receiver; and a control unit coupled to the radar and configured to measure a magnitude of the reflected electromagnetic wave received at the receiver from the reflector by measuring Doppler signal corresponding to the predetermined distance, wherein the control unit is configured to measure a reference value of the magnitude of the reflected electromagnetic wave when no intrusions are occurring, and wherein the control unit is configured to trigger an alarm when the magnitude of the reflected electromagnetic wave changes from the reference value.

A system, including: a radar including a transmitter and a receiver, the transmitter configured to transmit an electromagnetic wave; a reflector placed a predetermined distance away from the radar, the reflector configured to reflect the transmitted electromagnetic wave back to the receiver; and a control unit coupled to the radar and configured to measure a magnitude of the reflected electromagnetic wave received at the receiver from the reflector by measuring Doppler signal corresponding to the predetermined distance, wherein the control unit is configured to measure a reference value of the magnitude of the reflected electromagnetic wave when no intrusions are occurring, and wherein the control unit is configured to trigger an alarm when the magnitude of the reflected electromagnetic wave changes from the reference value.

A sensor unit comprising; a magnetic sensor adapted to detect a magnetic field; a light source adapted to transmit a radiation having a signature; a reflecting member for reflecting radiation emitted by the light source; a radiation sensor adapted to detect radiation reflected by the reflecting member; a controller adapted to generate a signal indicative of a security breach when the magnetic field is detected by the magnetic sensor and the signature is not identified in the radiation received by the radiation sensor.

A sensor unit comprising; a magnetic sensor adapted to detect a magnetic field; a light source adapted to transmit a radiation having a signature; a reflecting member for reflecting radiation emitted by the light source; a radiation sensor adapted to detect radiation reflected by the reflecting member; a controller adapted to generate a signal indicative of a security breach when the magnetic field is detected by the magnetic sensor and the signature is not identified in the radiation received by the radiation sensor.

A laser scanning sensor includes a distance data acquisition unit which acquires distance information in each measurement direction, and a memory which stores, as background distance information, a distance of an outer periphery of the detection area in each measurement direction. The sensor also includes a mirror surface determination unit which determines the presence of a reflecting surface when the distance information in continuous measurement directions is greater by at least a predetermined distance than the corresponding background distance information, and when this state changes thereafter by at least a predetermined rate in a predetermined time, a human body determination unit which extracts a portion of the distance information that may correspond to a human body and determines whether it corresponds to a human body, and an alarm output control unit which outputs an alarm signal when the presence of the reflecting surface or the human body is confirmed.

A laser scanning sensor includes a distance data acquisition unit which acquires distance information in each measurement direction, and a memory which stores, as background distance information, a distance of an outer periphery of the detection area in each measurement direction. The sensor also includes a mirror surface determination unit which determines the presence of a reflecting surface when the distance information in continuous measurement directions is greater by at least a predetermined distance than the corresponding background distance information, and when this state changes thereafter by at least a predetermined rate in a predetermined time, a human body determination unit which extracts a portion of the distance information that may correspond to a human body and determines whether it corresponds to a human body, and an alarm output control unit which outputs an alarm signal when the presence of the reflecting surface or the human body is confirmed.

A security apparatus forms a virtual security area. The security apparatus includes a radar sensor that transmits and receives a signal; and a reflector that reflects a signal output from a radar sensor of another security apparatus adjacent to the security apparatus. The security apparatus transmits a signal to a reflector of the another security apparatus adjacent to the security apparatus and receives a signal reflected by the reflector of the another security apparatus through the radar sensor to form a virtual security area between the security apparatus and the another security apparatus.

A process executes at an electronic system. The process identifies device characteristics of an imaging device that includes signal emitters and signal detectors. The process illuminates a field of view by signals from the signal emitters according to a modulation signal generated by the imaging device. At each of the signal detectors, the process obtains a response signal, and samples the response signals to form a response vector. The process obtains a lookup table corresponding to the modulation signal and the device characteristics. The field of view is partitioned into a 3-dimensional plurality of voxels, and the lookup table specifies, for each voxel, expected signals received by the signal detectors when the voxel is filled and the signal emitters illuminate the field of view according to the modulation signal. The process compares the response vector to the lookup table to determine which voxels are filled.