Abstract: An object detection device includes: a target information acquisition section that acquires information regarding a radar target detected by a radar and information regarding an image target detected by an image acquisition unit; and an object detection section that detects the presence of an object on the basis of whether or not each of a position of the radar target and a position of the image target are within a predetermined range. The object detection section determines whether or not the object is a pedestrian, and expands the predetermined range when it is determined that the object is a pedestrian from that when it is determined that the object is not a pedestrian.

Abstract: A system and method for pseudo real time collection of receive signal data in a single- or multi-channel ground penetrating radar. Each channel transmits electromagnetic impulses into a medium under test during each of a plurality of runs over the medium. Run receive signals are received in response to the transmitted impulses. Each run receive signal is sampled multiple times at a run sample rate. The sample points of each run are delayed by delay sequences with respect to the sample points of the other runs. The sample points of the individual runs are stored as a composite set of sample points representative of a receive signal sampled at an effective sample rate equal to a multiple of the run sample rate where the multiple is the number of runs.

Abstract: A method for detecting oil at the sea by means of a coherent oil spill radar with a transmitter and a receiver antenna includes the transmitter and receiver antenna being directed towards a sea surface in the near area out to a given distance of 1000-4000 m under a grazing angle of between 0.5 and 30 degrees, the transmitter antenna transmits at a frequency between 2 GHz and 18 GHz, and frequency modulated with an adjustable bandwidth and with a given transmitted effect less than 10 W. The transmitter antenna has a horizontal antenna lobe smaller than its vertical antenna lob. The transmitter and receiver antenna are controlled electronically to transmit and detect vertical polarization and horizontal polarization, with an adjustable modulation time of less than 4 ms between the polarizations.

Abstract: A method of using a directional sensor for the purposes of detecting the presence of a vehicle or an object within a zone of interest on a roadway or in a parking space. The method comprises the following steps: transmitting a microwave transmit pulse of less than 5 feet; radiating the transmitted pulse by a directional antenna system; receiving received pulses by an adjustable receive window; integrating or combining signals from multiple received pulses; amplifying and filtering the integrated receive signal; digitizing the combined signal; comparing the digitized signal to at least one preset or dynamically computed threshold values to determine the presence or absence of an object in the field of view of the sensor; and providing at least one pulse generator with rise and fall times of less than 3 ns each and capable of generating pulses less than 10 ns in duration.

Abstract: A projection detecting apparatus according to the present invention is that for detecting a projection on a surface of a running metal object, and includes a transmission antenna for radiating electromagnetic waves; a reception antenna for receiving reflected electromagnetic waves; and a transmission and reception signal processing section for processing a transmission signal and a reception signal. The transmission antenna and the reception antenna have unidirectionality and the transmission antenna and the reception antenna are installed in such a way that the reception antenna does not catch electromagnetic waves which have been radiated by the transmission antenna and reflected on the surface of the metal object and the reception antenna catches electromagnetic waves alone which have been radiated by the transmission antenna and reflected on the projection.

Abstract: A normalization processing circuit normalizes a position of a complex demodulation signal on a complex plane from an A/D converter, and outputs a normalized complex demodulation signal after the normalization to a multiple-dimensional feature extractor. The multiple-dimensional feature extractor calculates a feature quantity that changes when a person intrudes, a feature quantity that changes in wind and rain, and a feature quantity that changes when a spatially isolated intense electric field exists. A discriminator discriminates that a person has intruded based on the feature quantities of three dimensions.

Abstract: A method of using a directional sensor for the purposes of detecting the presence of a vehicle or an object within a zone of interest on a roadway or in a parking space. The method comprises the following steps: transmitting a microwave transmit pulse of less than 5 feet; radiating the transmitted pulse by a directional antenna system; receiving received pulses by an adjustable receive window; integrating or combining signals from multiple received pulses; amplifying and filtering the integrated receive signal; digitizing the combined signal; comparing the digitized signal to at least one preset or dynamically computed threshold values to determine the presence or absence of an object in the field of view of the sensor; and providing at least one pulse generator with rise and fall times of less than 3 ns each and capable of generating pulses less than 10 ns in duration.

Abstract: The present invention uses a Single Instruction Multiple Data (SIMD) architecture to form real time 3D radar images recorded in cylindrical near field scenarios using a wavefront reconstruction approach. A novel interpolation approach is executed in parallel, significantly reducing the reconstruction time without compromising the spatial accuracy and signal to noise ratios of the resulting images. Since each point in the problem space can be processed independently, the proposed technique was implemented using an approach on a General Purpose Graphics Processing Unit (GPGPU) to take advantage of the high performance computing capabilities of this platform.

Abstract: A radar device for an automotive radar system includes a base, a first antenna module including a first transmitting antenna and a plurality of first receiving antennas for emitting a detection signal and generating a first signal receiving result, wherein the first antenna is fixed on the base, a second antenna module including a second transmitting antenna and a plurality of second receiving antennas for emitting the detection signal and generating a second signal receiving result, wherein the second antenna is fixed on the base, and a control system disposed in the base and coupled to the first antenna module and the second antenna module for outputting the detection signal to the first transmitting antenna and the second antenna and processing the first signal receiving result and the second signal receiving result.

Abstract: In a radar apparatus, a peak extractor performs frequency analysis on a beat signal to obtain a frequency spectrum for each of first and second detection modes based on the beat signal for a corresponding one of the first and second detection modes. The peak extractor extracts a plurality of first peak-signal components from the frequency spectrum obtained for the first detection mode, and a plurality of second peak-signal components from the frequency spectrum obtained for the second detection mode. A determiner compares each of the plurality of first peak-signal components with a corresponding one of the plurality of second peak-signal components to deter mine whether a noise is included in the beat signal according to a result of the comparison.

Abstract: In exemplary implementations of this invention, a radio signal is transmitted between a transmitter and a receiver. Either the transmitter, or receiver, or both, have a directional antenna. When organic tissue passes between (or is stationary between) the transmitter and receiver, the tissue causes a reduction of the received signal strength (RSS) of the signal, as compared to a baseline RSS. The larger the amount of tissue, the greater is the reduction of the RSS. By analyzing the degradation of the signal, information about organic tissue between the transmitter and receiver may be determined. For example, the number of persons passing through a physical threshold may be determined. Or the fact that one person is walking faster than, and catching up with, a second person as they pass between the transmitter and receiver may be determined.

Abstract: An apparatus, system, and method for Gain Enhanced LTCC System-on-Package radar sensor. The sensor includes a substrate and an integrated circuit coupled to the substrate, where the integrated circuit is configured to transmit and receive radio frequency (RF) signals. An antenna may be coupled to the integrated circuit and a lens may be coupled to the antenna. The lens may be configured to enhance the gain of the sensor.

Abstract: A method of assessing an area for parking a vehicle includes ultrasonically scanning the area to obtain ultrasonic data, radar scanning the area to obtain radar data, and determining whether to park the vehicle in the area based on both the ultrasonic data and the radar data.

Abstract: A Luneburg lens is used in conjunction with a patch antenna array. The patch antenna array is conformed or adapted to cover a portion or backside of the Luneburg len's surface with the backplane of the conformed antenna array defining a field of regard (FOR) in which objects are detected and tracked. A processor is connected to a receiver/exciter module which connects to transmit/receive modules which are connected to the individual patch antennas through a network of MEMS switches. In a receive mode, selected subarrays of the conformed patch antenna array are scanned during selected time intervals with the sum and delta beams being formed coherently in amplitude and phase to realize amplitude monopulse sensing and angle tracking of an object.

Abstract: A system and method for space control and remote monitoring is disclosed. According to one embodiment, a frequency modulated signal is emitted from a radioscopic device having an antenna. The frequency of the reflected signal from a target is compared with the emitted frequency modulated signal to obtain a low-frequency signal. The low-frequency signal is processed to form signal pulsations spectrum using a fast Fourier transform. Each spectrum frequency represents a distance to the target.

Abstract: Provided is an object identification device and a method for the same that are capable of identifying a three-dimensional object and a road surface static object, irrespective of situations. The object identification device identifies an object, based on a transmission signal and a reflection signal caused by the object reflecting the transmission signal. The object identification device includes: a measurement section configured to measure at least one of the relative distance and the relative velocity with respect to the object; an intensity detection section configured to detect the intensity of the reflection signal; and an object identification section configured to identify the object which can be an obstacle object, based on at least one of the relative velocity and the variation in the relative distance, and on the variation in the intensity.

Abstract: A method for operating a radar system on a vehicle to reduce nuisance alerts caused by a stationary structure proximate to the vehicle. The method includes determining a stationary count indicative of the number of targets detected by the radar system that are within a travel path of the vehicle and are classified by the radar system as stationary, and indicating that the vehicle is proximate to a stationary structure if the stationary count is greater than a count threshold.

Abstract: An on-board radar apparatus includes an antenna unit configured by combining one of a lens and a reflector, and a plurality of antenna elements, a transmission and reception unit configured to emit a radio wave using, for at least one of transmission or reception, a partial antenna of a plurality of patterns configured by the antenna elements that are part of the plurality of antenna elements, and to receive a reflection wave obtained by reflection of the radio wave from an object, and a detection unit configured to detect the object based on the reflection wave received by the transmission and reception unit.

Abstract: An object detecting device includes a signal transmitting and receiving unit configured to generate an intermediate frequency signal based on a transmission signal and a reception signal which is a reflected wave thereof, a processing unit configured to determine that an image of a target peak frequency is a virtual image based on noise when it is determined that a peak frequency of predetermined n times the target peak frequency is not present in information based on the intermediate frequency signal generated by the signal transmitting and receiving unit and to detect an object based on the determination result, where n is an integer of 2 or greater.

Abstract: An apparatus includes an extendable wand, and a sensor head coupled to the wand. The sensor head includes a continuous wave metal detector (CWMD) and a radar. When the wand is collapsed, the wand and the sensor head collapse to fill a volume that is smaller than a volume filled by the sensor head and the wand when the wand is extended. Frequency-domain data from a sensor configured to sense a region is accessed, the frequency-domain data is transformed to generate a time-domain representation of the region, a first model is determined based on the accessed frequency-domain data, a second model is determined based on the generated time-domain representation, the second model being associated with a particular region within the sensed region, and a background model that represents a background of the region is determined based on the first model and the second model.

Abstract: A radar apparatus to detect an object includes a detecting unit configured to detect the object based on a reflected wave received in response to transmitting a transmission wave, in order to output a detection result of the object, a storage unit including a first storage part to store the detection result, and a second storage part to store a copy of information stored in the first storage part based on a copy command, and a selecting unit configured to select one of the first storage part and the second storage part as an access destination, in order to output the detection result stored in one of the first storage part and the second storage part selected as the access destination.

Abstract: A method and system (10) are provided for monitoring a restricted area (12) below a temporarily elevated worker (14) working on an elevated power transmission line (16). The method and system (10) utilize a Doppler radar module (40) that is temporarily elevated to a location (32) adjacent the worker (14) and that is configured to detect the presence of personnel (34) who enter the restricted area (12). The system (10) is configured to automatically alert personnel (34) at the worksite (17) who enter the restricted area (12) in response to detection of the personnel (34) by the Doppler radar module (40).

Abstract: A signal processor (30) for a submillimeter wavelength active radar system (10, 20, 30) processes signals received and downconverted by the radar system, the downconverted signals corresponding to a given pixel of the field of view having time varying amplitude and phase components which have a periodic component which is dependent on content. Information about the content is discriminated from the periodic component. By using phase rather than only amplitude, there is additional information in the downconverted signals. The phase is more sensitive to changes in the content such as objects, background and atmospheric conditions, than amplitude alone. The phase information enables the periodic component to be retained which can be characteristic of the content owing to content flutter, changes in submillimeter standing waves and interference fringes in received reflections of submillimeter illumination if surface layers have a thickness of a number of half wavelengths.

Abstract: Disclosed are passive millimeter wave detection devices that in some embodiments are useful for detecting objects such as weapons obscured underneath clothing. Also disclosed are methods for detecting objects using millimeter waves, in some embodiments, objects such as weapons, obscured underneath clothing.

Abstract: This disclosure provides a radar device, which detects an object of interest from image data produced based on an input signal containing echo signals caused by transmitted signals reflecting on objects. The radar device includes a memory module for storing template image data produced based on one or more characteristics of the echo signals of the object of interest, a pattern matching module for performing pattern matching of the image data and the template image data, an identifying module for identifying an area within the image data containing the object of interest corresponding to the template image data, when the object of interest is detected from the image data as a result of the pattern matching.

Abstract: Systems and methods are disclosed for displaying the current trends (i.e., turning or going straight) or the future positions of vehicles of interest on a traffic display unit. The position, orientation and geometry of the displayed symbology is a function of parametric information broadcast by the vehicles of interest and processed by a computer system that controls the traffic display unit. In particular examples disclosed herein, the traffic display unit is a navigation display on an aircraft or a traffic display unit at a traffic controller's station. However, the methods disclosed herein have application to vehicular traffic other than aircraft, such as boats or ships.

Abstract: A mobile object detecting apparatus includes first radiation detecting means; and second radiation detecting means for radiating an electromagnetic wave having the same frequency as the electromagnetic wave radiated by the first radiation detecting means such that the radiated electromagnetic wave passes near a point in the first radiation detecting means from which the electromagnetic wave is radiated, and detecting a standing wave which is generated due to reflection of the radiated electromagnetic wave at an object; wherein a distance, over which the electromagnetic wave radiated by the first radiation detecting means travels until it reaches near the first radiation detecting means, corresponds to a distance of an integral multiple of a wave length of a half cycle of the electromagnetic waves radiated by the radiation detecting means plus a wave length of a predetermined period which is smaller than the half cycle.

Abstract: A system and method for detecting dangerous objects and substances are disclosed. According to one embodiment, a method comprises generating a microwave signal that is reflected by a target to render one or more reflected signals. The one or more reflected signals are received at an antenna array. The one or more reflected signals are converted into digital reflected signals. The microwave signal is converted into a digital signal. The digital reflected signals and the digital signal are processed to determine the three dimensional position of the target. The digital reflected signals and the digital signal are processed to identify the target. The digital reflected signals and the digital signal are processed to determine a state of the target; and determine whether the target a dangerous object.

Abstract: A radar sensor for motor vehicles, having a transmitting part, which has two oscillators and a 90° phase shifter for generating a transmission signal, a first comparison signal, and a second comparison signal, which is phase shifted by 90° with respect to the first comparison signal, and a receiving part having an I mixer for mixing a received signal with the first comparison signal and a Q mixer for mixing the received signal with the second comparison signal, in which the transmitting part has a first transmit mixer, whose inputs are directly connected to the two oscillators, and a second transmit mixer, whose one input is directly connected to a first of the two oscillators and whose other input is connected via the phase shifter to the other oscillator.

Abstract: A driving assist apparatus for a vehicle is disclosed. The driving assist apparatus includes a transmitter for transmitting a transmission wave, a receiver for receiving a reflected wave, an obstacle presence determination section for detecting a presence of an obstacle in the surrounding of the vehicle based on the reflected wave, a measurement section for measuring a frequency of phase delay and advance of the reflected wave with respect to a reference signal, and a detection section for detecting the obstacle having a specific relation with the vehicle based on the presence of the obstacle determined by the obstacle presence determination section and the frequency of delay and the frequency of advance measured by the measurement section.

Abstract: A sensor has a strip resonator filter that energizes an emitter patch which emits an electric field out from the strip resonator filter (away from the strip resonator filter). The capacitance of the filter, or specifically the coupling capacitance and radiation pattern of the slotted patch, is altered when an object such as a finger is near the sensor. Resulting changes in a signal outputted by the filter can be used to determine how close the object is to the sensor. The strip resonator filter may be a half wavelength strip resonator coupled filter having three separate strips. The patch may have a slot and two accompanying strips. An arrangement of multiple sensors may detect the position of an object in two or three dimensions.

Abstract: Signals received by an array of sensing elements are processed by first positioning the sensing elements in a uniform grid of L locations, wherein each location to include or not to include a sensing element is selected during a design phase. The sensing elements are selected and grouped into subsets, wherein each subset contains one or more sensing elements, and each sensing element is a member of one or more subsets. The signals in each subset are linearly combined to produce a combined signal, which is then sampled to form an output channel, which can detect objects.

Abstract: There is provided a radar apparatus for detecting a target. A detection signal generating unit generates detection signals of the target based on transmission and reception waves of antennas. A detection signal processing unit performs frequency analysis on the detection signals to extract signal components of the target, and performs a predetermined process on the signal components to calculate at least one of a distance to the target, a relative speed to the target, and an orientation of the target. The detection signal generating unit includes a filter unit for giving changes to the detection signals in a frequency bandwidth higher than Nyquist frequency which is a half a sampling frequency. The detection signal processing unit acquires the signal components from the detection signals to which the filter unit gives the changes to determine whether the signal components are generated by replication due to the Nyquist frequency.

Abstract: Embodiments of a target classifier and method for target classification using measured target epsilons and target glint information are generally described herein. The target classifier is configured to compare a total epsilon measurement with target glint information to determine whether to the target being tracked corresponds to an intended target type. Based on the comparison, the target classifier may cause target tracking circuitry of a target-tracking radar to either continue tracking the target or break-off from tracking the target. Glint of different target types may be characterized at different ranges and the target's glint characteristics may be used to distinguish intended from non-intended targets. Accordingly, intended targets such as incoming artillery may be distinguished from non-intended targets such as aircraft to help prevent countermeasures from being launched against non-intended targets.

Abstract: A method for detecting icing at an angle-resolving radar sensor in a driver assistance system for motor vehicles, in which signals of a plurality of antenna elements each having a specific angle characteristic are compared with the corresponding angle characteristics, and the azimuth angle of a located object is determined on the basis of an angle fit quality which indicates how well the signals of the antenna elements correspond to the angle characteristics for a given azimuth angle, wherein an indicator for icing is formed which is a monotonically falling function of the angle fit qualities of the located objects, with objects having a low signal-to-noise ratio being included in the indicator at the most with a reduced weighting.

Abstract: A hybrid mm-wave imaging system which increases the probability of detection and reduces false alarm rate. The system includes a large array of passive sensors (pixels) to provide an initial coarse picture of the environment and a small array of active sensors in the center of the large array, which is activated only when the initial passive scan detection is positive. The active array, without any mechanical scanning, illuminates the area to detect edges to provide clarity to the detected image, thereby increasing the probability of detection and reducing the false alarm rate.

Abstract: A system includes: a radar scanner disposed to scan the interior of a container; an interrogator in communication with the scanner; and a processing system in communication with the interrogator, in which the processing system displays information about the interior of the container. A method includes: mounting a radar scanner antenna to a container so as to scan the interior of the container; connecting a coupler to the scanner so that the scanner communicates scanning data via the coupler to the exterior of the container. Another method includes: coupling an interrogator and radar processing system to a scanner mounted on a container; and processing radar scan data from the interior of the container. Another method includes: linking a radar processing system via a communications link to an interrogator that is coupled to a scanner mounted on a container; and processing radar scan data from the interior of the container.

Abstract: Methods and apparatuses for providing wide-area surveillance with a radar and/or other sensors from a stratospheric balloon launched from a land or ship platform for detection, tracking, and classification of maritime, land, and air objects such as ships, people/vehicles, or aircraft are described generally herein. In one or more embodiments, an apparatus is battery operated and includes a stratospheric balloon filled that is filled with helium when it is launched and a gondola with a radar system and communication equipment suspended therefrom. When launched, the apparatus can travel with the wind until it reaches an altitude of approximately 68,500 ft., then it can move substantially horizontally with the stratospheric winds until it returns to earth via a parachute. Multiple apparatus launches at periodic intervals can help provide continuous coverage of the surveillance area. The apparatus can be recovered and re-used or can be considered expendable.

Abstract: An exemplary embodiment relates to an aircraft system for detecting wires. The system includes a processor configured to actively sense a presence of a first object and a second object. The processor determines a location of the first object and the second object. The processor determines a potential location of a wire between the first object and the second object. The processor actively senses the wire by providing electromagnetic energy to the potential location.

Abstract: A method of determining an angle within the beam to a target using an airborne radar includes receiving first data associated with first returns associated with a first portion of an antenna. The method further includes receiving second data associated with second returns associated with a second portion of an antenna, wherein the first portion is not identical to the second portion. The method further includes determining the angle within the beam to the target using the first and second data.

Abstract: A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across a surface and that travels down the surface. The detection system converts the return signals from a time domain to a frequency domain, resulting in frequency return signals. The detection system then performs a singular value decomposition for each frequency to identify singular values for each frequency. The detection system then detects the presence of a subsurface object based on a comparison of the identified singular values to expected singular values when no subsurface object is present.

Abstract: A negative obstacle detection system for a vehicle comprises a stereo camera mountable to the vehicle to provide a forward facing image and a long range radar mountable to the vehicle to emit a signal in a forward direction from the vehicle. An electronic control unit receives data from the stereo camera and the long range radar to determine if a negative obstacle may be located in a forward proximity to the vehicle.

Abstract: A system that applies attribute and topology based change detection to networks of objects that were detected on previous scans of a structure, roadway, or area of interest. The attributes capture properties or characteristics of the previously detected objects, such as location, time of detection, size, elongation, orientation, etc. The topology of the network of previously detected objects is maintained in a constellation database that stores attributes of previously detected objects and implicitly captures the geometrical structure of the network. A change detection system detects change by comparing the attributes and topology of new objects detected on the latest scan to the constellation database of previously detected objects.

Abstract: A method and apparatus is devised for detecting command wires utilized to detonate an improvised explosive device or other objects of interest in which frequency-scanned RF in the HF region of the electromagnetic spectrum is projected out across a given area and returns are detected and converted into image data in which phase, amplitude, range and frequency associated with the incoming data is correlated with frequency-dependent range templates to determine the existence of, the range of and the direction of command wires or other objects of interest.

Abstract: In one embodiment, an active array antenna device includes: M (M?2) bandpass filters to filter signals received by M antenna elements; M low noise amplifiers to amplify the filtered received signals; M distributors to distribute respective of the M amplified signals into N (N?2) distributed signals; M sets of N phase shifters provided for respective of the M distributors to shift phases of the N distributed signals; M sets of N attenuators to attenuate N phase-shift signals; N beam synthesis circuits provided for N sets of the M attenuators to synthesize a beam by summing attenuator outputs from the M attenuators corresponding to the M distributors; a heat insulating container accommodating the low noise amplifiers and the receiving filters and formed of a superconductor material; and a cooler to cool the receiving filters and the low noise amplifiers to make the receiving filters in a superconducting state.

Abstract: Energy harvesting devices provide power to devices of emergency equipment stations (e.g., fire extinguisher station, fire alarm pull station, defibrillator station, etc.) distributed throughout a facility to monitor one or more internal or external conditions (e.g., identifiable objects detected near the station, presence of an obstruction restricting access to the station, etc.) and relay information about the monitored conditions to a central station.

Abstract: An unmanned aerial vehicle (UAV) radar apparatus may be used in aircraft detection and avoidance. The radar apparatus may include an RF front end configured to transmit and receive RF signals, a filtering module coupled with the RF front end module that filters RF signals received at the RF front end module, and a target data processing module coupled with the filtering module that detects and identifies one or more targets based on the filtered RF signals. Avoidance procedures may be initiated based on the identification and detection of one or more targets.

Abstract: A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes the return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

Abstract: Methods are described for radar detection of persons wearing wires using radar spectra data including the vertical polarization (VV) radar cross section and the horizontal polarization (HH) radar cross section for a person. In one embodiment, the ratio of the vertical polarization (VV) radar cross section to the horizontal polarization (HH) radar cross section for a person is compared to a detection threshold to determine whether the person is wearing wires. In another embodiment, the absolute difference of the vertical polarization (VV) radar cross section and the horizontal polarization (HH) radar cross section for a person is compared to a detection threshold to determine whether the person is wearing wires. To reduce false positives, other additional indicators, such as speed of movement, and or visual features of the person, can be used to further narrow a person suspected of wearing wires.

Abstract: A passive detector (10) includes a receiver (11) configured to collect passive radiation (12) in an environment, where detailed information about a portion of the passive radiation is estimated as a baseline of the passive energy. The passive energy is generated by a passive source unrelated to the detector. A monitor (24) is configured to measure a fluctuation in the baseline. A decision module (34) is coupled to the monitor to determine whether the fluctuation represents a presence or motion in the environment. Detection methods are also disclosed.