Abstract: A method for generating a representation of a kinematic structure of an atmospheric vortex is provided. The method comprises receiving a plurality of signals from a Doppler radar. The signals are reflected at a plurality of pulse volumes. The method also comprises measuring a plurality of Doppler velocities based on the received signals. A plurality of scaled Doppler velocities are calculated representing the plurality of measured Doppler velocities, the radial distance between the Doppler radar and the pulse volume where the Doppler velocity is measured, and the distance between the radar and a first estimated atmospheric vortex center. The method also comprises generating a representation of the kinematic structure of the atmospheric vortex using the plurality of scaled Doppler wind velocity values.

Abstract: A method for clutter filtering staggered pulse repetition time data signals is provided. The method comprises the steps of receiving a plurality of staggered pulse repetition time data signals. The data signals may comprise one or more desired signals and one or more clutter signals. The method further comprises separating the staggered pulse repetition time data signals into a first separated data sequence and a second separated data sequence. The first and second separated data sequences comprise equally spaced data samples. The method also comprises the step of filtering the one or more clutter signals from the first and second separated data sequences.

Abstract: A receiver, such as a miniaturized microwave-photonic coherent receiver (MMPR) is disclosed. The receiver includes an antenna to output an electrical RF signal received on a section of the antenna, a laser to produce an optical signal, a photonic modulator to receive the optical signal and the electrical RF signal and produce an EO-RF signal and to receive the optical signal and an electrical LO signal and produce an EO-LO signal, a signal combiner to provide a combined EO-RF and EO-LO signal and a photodiode to receive the combined signal and produce an IF signal. A method of detecting an object using the MMPR includes receiving an electrical RF signal corresponding to the object, outputting the electrical RF signal to a photonic modulator, modulating the electrical RF signal onto an optical carrier, demodulating the electrical RF signal to produce an IF signal and processing the IF signal.

Abstract: The invention, called “ORSE Track Fusion”, combines sensor tracks from dispersed sites, when limited communication bandwidth does not permit sharing of individual measurements. Since estimation errors due to maneuver biases are not independent for each sensor, optimal fusion of tracks produced by Kalman filters requires transmission of all the filter gain matrices used to update each sensor track prior to the fusion time. For this reason, prior art has resorted to suboptimal designs. ORSE Track Fusion according to aspects of the invention overcomes this disadvantage by propagating, transmitting, and fusing separately calculated covariance matrices for random and bias estimation errors. Furthermore, with ORSE, each sensor can have its own criteria in forming its track, and track fusion can be performed with different criteria at each processing site. Thus, ORSE Track Fusion has the unique flexibility to optimize track fusion simultaneously for multiple criteria to serve multiple users.

Abstract: A digitally tuned digital radio frequency memory that captures a portion of a first radio frequency signal and retransmits the portion as a coherent radio frequency signal. The digitally tuned radio frequency memory may include a track and hold configured to track and hold the first radio frequency signal and to output a shaped signal; a digitizer configured to convert the shaped signal to a digital word; a memory configured to store the digital word; and a direct digital frequency synthesizer configured to provide a sampling clock signal, wherein the sampling clock signal is provided to the track and hold.

Abstract: A perimeter antenna array for a radar, in particular a slope monitoring radar, formed from a pair of parallel linear arrays of receiver elements and a pair of parallel linear arrays of receiver elements, together forming a rectangle of receiver and transmitter elements. Signals are switched to the transmitter elements and received by the receiving elements. The signals are processed to obtain signals for virtual elements located equidistant between transmitting and receiving elements. The signals from the virtual elements are analyzed to produce a radar image.

Abstract: Embodiments of the invention process a radar image arising from a radar antenna, by reading the reflectivity information associated with each pixel forming the radar image, processing the reflectivity information, pixel by pixel, with the aid of a first procedure. The method further includes a second processing of the radar image using a second procedure that includes extracting objects from the radar image, then calculating the extent and the position of each object, with the aid of an angular aperture between two signals. For each part of the radar image processed by the first procedure, corresponding to an extracted object, pixel within the result of the first procedure are replaced by corresponding pixels of the radar image processed by the second procedure, if the reflectivity value associated with the second pixel is greater than the reflectivity value of the first pixel, the parts of the radar image corresponding to zones situated at a distance greater than a given threshold from the radar antenna.

Abstract: A method and device are provided for measuring distance and relative speed of a plurality of objects with the aid of an FMCW radar, transmitted signals being reflected by objects, and the reflected signals being received and mixed with the transmitted signals. A combination of distance and relative speed values is assigned to the mixer output frequencies of each frequency ramp for each object, and the distance and relative speed of a possible object are determined from points of intersection of a plurality of distance and relative speed combinations. The apparent (unreal) objects are eliminated by modifying the frequency slope of at least one frequency ramp according to the random principle in a subsequent measurement cycle.

Abstract: Provided is a semiconductor device for a spread spectrum radar apparatus which suppresses spurious signals resulting from non-linearity of active elements. The semiconductor device as the inverse spread spectrum modulation unit for the spread spectrum radar apparatus has a coupled line of two lines and another coupled line of two lines. The semiconductor device includes: an unbalanced to balanced transforming circuit which converts a received signal inputted as an unbalanced signal into a balanced signal pair; a switch circuit having one or more transistors; and a balanced inverse spread spectrum circuit which obtains as differential signal PN signals belonging to the same sequence code as a PN code which is used to generate an original signal of the received signal, also obtains the balanced signal pair from the unbalanced to balanced transforming circuit, and performs inverse spread spectrum modulation on the balanced signal pair by the switch circuit using the PN codes inputted as the differential signal.

Abstract: A scan-to-scan integrator for use in radar apparatus comprises means for defining a search window for use in verifying a candidate detection. The window is bounded by the intersection of a first zone and a second zone, wherein the first zone comprises a rectangular reference frame aligned detection window, and the second zone comprises a range estimate tolerance region defined by a range estimate for the candidate detection and predetermined tolerance limits.

Abstract: A synthetic aperture radar to provide high resolution in the azimuth direction under the predetermined conditions of wide observation swathwidth in the range direction, stripmap observation and free PRF (Pulse Repetition Frequency) comprises a transmission antenna 102 for a single system and receiving antennae 104a, 104b for two systems. The beam width in the azimuth direction of a transmission beam 103 from the transmission antenna 102 is set equal to twice as wide as the beam width of each of the receiving antennae 104a, 104b. Moreover, a receiving antenna beam 105a is directed to the moving direction, while the other receiving antenna beam 105b is directed to opposite to the moving direction. The transmission antenna 102 and the receiving antennae 104a, 104b for two systems are used in common by dividing a single array antenna in the elevation direction to configure the receiving antennae 104a, 104b.

Abstract: A system and method for performing passive coherent location (PCL). A PCL radar system has high speed analog-to-digital converters (ADC) for digitizing RF signals received on antenna elements of an antenna array. The RF signal received by each antenna element is processed by components within a corresponding physical channel. The RF signals are digitized by the high speed ADC and then processed by a frequency channelizer. The frequency channelizer inputs the RF signal into a digital filter bank comprising a plurality of band pass filters. Each filter in the filter bank may have a corresponding filters, which share the same filtering properties, in the frequency channelizers of each of the physical channels. The outputs of such corresponding filters share a frequency channel. Beam forming and PCL processing are performed for each frequency channel on the filter outputs from each physical channel sharing said frequency channel. A target state is estimated.

Abstract: An improved radar system and method for detecting targets is described. The invention discriminately detects and analyzes a target by sub-dividing it into sections, and then, in combination with a sliding window integrator, assimilates accumulated high resolution channel and low resolution channel data to construct a complete image.

Abstract: A digital radar system includes a transmitter, the transmitter configured to transmit a signal; a receiver, the receiver configured to receive a return signal; and two analog to digital conversion (ADC) units, the ADC units configured to digitize the return signal at a rate higher than a Nyquist rate for the transmitted signal. A method of operating a digital radar includes transmitting a signal via a transmitter; receiving a return signal via a receiver; and digitizing the return signal by two analog to digital conversion (ADC) units at a rate higher than a Nyquist rate for the transmitted signal.

Abstract: A radar array antenna comprising: a plurality of analog to digital (A/D) converters for converting analog signals from the array to digital signals, the signals supplying input to one or more optical modulators having controllable wavelengths, each optical modulator connected to a corresponding multiplexer, the multiplexer providing outputs to a demultiplexer that distributes the signals to a beamformer.

Abstract: A radar target detection method in which an azimuth at which a target is located is detected on the basis of reception signals obtained through antenna elements of an array antenna by detecting a change in levels of spectrum peaks in an azimuth spectrum of reception signal intensities, calculating a level of correlation between the level change of each spectrum peak and a directivity pattern of the array antenna in an azimuth range corresponding to the spectrum peak, and determining an azimuth corresponding to one of the spectrum peaks having the highest corresponding correlation level to be the azimuth at which the target is located.

Abstract: The invention relates to a method for pre-detecting responses in a secondary radar. It applies in particular to the detection of mode S responses. An aim of the invention is to process the signals received before decoding the responses so as to allow the detection of mixed responses, and avoid the detection of ghost responses. For this purpose, the invention has in particular as subject a method for pre-detecting responses in a secondary radar, the responses to be pre-detected comprising a message coded by a modulated signal, characterized in that the presence of a signal exhibiting modulation characteristics in accordance with those of a message of a response to be pre-detected is identified; the duration of the signal identified is measured; this duration is compared with a minimum duration, this minimum duration being determined on the basis of the duration of the messages of the responses to be pre-detected.

Abstract: Marine radar systems and methods for producing low power, high resolution range profile estimates. Non-linear Frequency Modulation (NLFM) pulse compression pulses are frequency stepped to form a low power, wide-bandwidth waveform. Periodically, calibration filters are determined and applied to return signals for correcting non-ideal effects in the radar transmitter and receiver.

Abstract: Systems and methods are described for monitoring the surface flow velocity and volume discharge of rivers and channels using a VHF/UHF radar located in operative relationship with a riverbank. This frequency region allows precise estimation and removal of the Bragg wave velocity; it also is matched to the short wind-wave roughness periods existing on river surfaces so that operation is possible nearly all the time. Methods of bearing determination are also disclosed. Up/downriver surface velocity profiles vs. distance across the river may be constructed from maps of the radial velocity component from a single radar at thousands of points within the radar's coverage. Methods to compensate for Doppler aliasing under high flow conditions are also shown.

Abstract: An electronic scanning radar apparatus has a cutting portion for cutting receiving data which is comprised of N numbers of data for each channel into two more short time data having M (<N) numbers of data in a time direction for each channel, an inverse matrix estimator for computing and estimating an inverse matrix of the time series correlation matrix from the short time data, and a phase information producing portion for computing CAPON phase information out of the estimated inverse matrix of the time series correlation matrix in order to detect a distance, an azimuth and a relative speed of a target on the basis of a computed CAPON phase information.

Abstract: The invention relates to the methods and systems for remotely detecting metal items, for example, weapons, concealed in cloths or belongings and may be used in security complexes. The proposed system contains a phased antenna array 1 radiating a continuous frequency-modulated ultra high or super high frequency signal and scanning a controlled space, a receiver 2 of reflected signals, a processor 3, a display 4, and a video camera 5.

Abstract: An all-digital line-of-sight (LOS) process architecture addresses the size, weight, power and performance constraints of a receiver for use in semi-active or active pulsed electromagnetic (EM) targeting systems. The all-digital architecture provides a platform for enhanced techniques for sensitive pulse detection over a wide field-of-view, adaptive pulse detection, LOS processing and counter measures.

Abstract: An all-digital line-of-sight (LOS) process architecture addresses the size, weight, power and performance constraints of a receiver for use in semi-active or active pulsed electromagnetic (EM) targeting systems. The all-digital architecture provides a platform for enhanced techniques for sensitive pulse detection over a wide field-of-view, adaptive pulse detection, LOS processing and counter measures.

Abstract: A target detection apparatus that includes a transmission/reception device for generating a transmission signal for detection of a target, and extracting distance information about the target from a received signal; a number of sensors each of which transmits the transmission signal to respective different angle ranges, receives a signal reflected by the target, and transfers the received signal to the transmission/reception device; and a switch device for switching in a time division manner a connection between the transmission/reception device and one of the sensors to a connection between the transmission/reception device and another one of the sensors, where the switch device selects a first of the sensors for transmitting the transmission signal in a time slot and a second of the sensors for receiving the signal reflected by the target in the time slot.

Abstract: An apparatus and method of determining location of an object hidden from view. The apparatus includes an imaging tool for detecting hidden objects. The imaging tool includes a housing including a first end and a second end, a display supported by the first end of the housing, and a tracking device supported by the second end of the housing. The imaging tool also includes a transmitter supported by the housing and operable to transmit electromagnetic radiation toward a hidden target, an analysis module supported by the housing and operable to analyze feedback data related to the interaction between the target and the electromagnetic radiation, and an image module operable to receive data from the analysis module to generate an image on the display.

Abstract: A radar system transmits a beam of detection radio waves with a predetermined azimuth width, receives a reflected wave from a target, changes a central azimuth of the beam, and detects the distribution of reception signal strengths at predetermined angular intervals and for each predetermined distance. Then, when the reception signal strength distribution associated with changes in azimuth is expressed in rectangular coordinates, an azimuth corresponding to a vertex of an isosceles triangle that approximates the reception signal strength distribution and has an azimuth width, which is determined by the beam azimuth width, as its base is detected as the central azimuth of the target.

Abstract: A circuit for a display used on an aircraft causes the display to display a composite terrain image. The composite terrain image can be formed from first terrain data from a terrain database and second terrain data from a radar system. A display control circuit can generate a display signal for the composite terrain image. The display signal is received by the display. The composite terrain image can be viewed by a pilot.

Abstract: An in-vehicle radar apparatus includes a beam emitting part that emits a beam, a casing that supports the beam emitting part, and a reference unit that is attached to the casing and is equipped with multiple surfaces usable as a reference plane. A surface of the casing to which the reference unit is attached and the reference plane form an angle that depends on which one of the multiple surfaces is used as the reference plane.

Abstract: Techniques for detecting contraband are described, as are techniques for generating an image of living tissue. A location of interest relative to a target space is received, and a radar signal is transmitted in the direction of the location of interest. Portions of the radar signal are detected with multiple receiving structures. The detected portions are processed to generate information corresponding to dielectric or loss properties, the properties corresponding to particular positions within the target space. A determination is made as to whether contraband is present in the target space based on the determined properties.

Abstract: Systems and methods are provided for determining first and second azimuth angle values representing two closely spaced targets. Monopulse radar scan data is produced and processed to provide quadrature angle data, merged azimuth angle data, and a maximum magnitude of the quadrature angle. A quadrature angle methodology that derives the first and second azimuth angle values from an integration of the quadrature angle data over an angular region within the monopulse scan is applied if the maximum quadrature angle magnitude exceeds the threshold value. A merged azimuth angle methodology that fits the merged azimuth angle data to a polynomial as a function of a boresight angle of the monopulse radar to derive the first and second azimuth angle values is applied if the maximum quadrature angle magnitude does not exceed the threshold value. The first and second azimuth angle values are then displayed to a user.

Abstract: There is provided a radar system for detection of one or more objects. The radar system comprises a radar wave transmitter for simultaneously transmitting a CW radar signal and a FM-CW or MF radar signal, and a first radar wave receiver for receiving CW and FM-CW or MF radar signals, reflected from one or more objects present in a detection range of the radar system. The system may further comprise a first CW mixer for mixing CW transmission signals and reflected CW signals received by the first receiver, and a first FM-CW or MF mixer for mixing FM-CW or MF transmission signals and corresponding reflected FM-CW or MF signals received by the first receiver.

Abstract: By using the delay profile created by delay profile creating section 102 and the first threshold value 330 received from the first threshold value calculation 105, the first threshold value timing detection section 103 selects only the earliest receive timing exceeding the first threshold value, from all the timing that the correlation value in the delay profile becomes a maximum. By using the receive timing and the second threshold value 331 received from the second threshold value calculation section 107, reference timing calculation section 106 selects the reference timing required for calculating the receive timing for the incoming wave of the minimum propagation delay time. The timing delayed by previously set timing behind said reference timing is sent from receive timing calculation section 108 as the receive timing 113 of the incoming wave of the minimum propagation delay time.

Abstract: A target detecting apparatus mounted on a vehicle has an electronically agile radar detecting a beat signal indicating a difference in frequency between transmission and reception signals and producing a time series of N reception data from the beat signal, a determining unit determining search areas placed at different ranges of distance from the vehicle while considering a running state of the vehicle and determining a data length for each search area, an extracting unit extracting (N?M+1) time series of short time data, respectively, having the data length corresponding to M reception data from the N reception data for each search area, a producing unit producing phase information from the short time data for each search area, and a detecting unit determining a target distance and a target bearing from the phase information and detecting a target from the target distance and the target bearing.

Abstract: A system is disclosed for position registration and phase synchronization of monitors in a monitor network. Each monitor includes a transceiver having a transponder circuit with a calibrated transponder delay. To measure a distance between monitors, an oscillator at a first monitor generates a measurement signal which is transponded by a second monitor for receipt by the first monitor. A phase difference between the received signal and the first monitor oscillator is determined and used with the signal velocity and transponder delay to calculate the distance between monitors. The measured distances are combined with other data (e.g. monitor elevations) to calculate monitor locations. A phase delay is then measured by transmitting a signal from the first to the second monitor for comparison with the second monitor oscillator. A phase difference between oscillators (for use in synchronizing the monitors) is then calculated using the phase delay, separation distance and signal velocity.

Abstract: A radar system comprises a transmitter that transmits a predetermined wideband signal, a digital receiver that records a returned signal using a one-bit ADC, a random noise source that is added to the transmitted or returned signal, a processing means where the received signal is distorted to compensate for the effect of the noise on the receiver. The predetermined wideband signal may be a pseudo random noise signal. The processing may include averaging prior to cross-correlation.

Abstract: According to one embodiment, a radar tracking system includes a radar coupled to a radar processing system. Radar processing system receives images from the radar and that are each obtained at a differing angular orientation of the radar to a target. Radar processing system dithers each image along its azimuthal extent and then combines the dithered images to form an enhanced image of the target.

Abstract: A method and system for analyzing the RCS of an object using N Point signature prediction models is provided. N-point signature prediction models are created for each object in a scenario and stored in lookup tables. Shooting and Bounce trace back techniques are used to determine RCS signatures of multiple objects in modeled scenarios to account for blockage by and coupling phenomena of a scattered field.

Abstract: A system for processing a signal comprises a transmit unit to transmit a signal, and a receive unit receiving the signal and performing equivalent time sampling thereon by sampling each cycle of the received signal and reconstructing the received signal from the samples, wherein the receive unit applies a plurality of down-conversion rates to the equivalent time sampling for an acquisition window.

Abstract: A satellite navigation receiver having a digital front end. The satellite navigation receiver includes an analog section for receiving, amplifying, and filtering a satellite navigation signal. The digital front end is coupled to the analog section and is used to perform digital signal processing on the satellite navigation signal before it is passed on to the acquisition and tracking engines. By off-loading some of the functionality from the analog section to the digital front end, the analog section may be made smaller and cheaper and may consume less power. Moreover, additional functionalities can be added to the digital front end to improve performance. Since the digital front end is comprised of digital circuitry, it scales down in size, cost, and power with advances in semiconductor fabrication techniques.

Abstract: Communication between a remote locator and a transponder is used to determine the relative position of the transponder. The transponder and locator each include a transmitter and a receiver. The locator transmits an inquiry in the form of a relatively powerful cyclically encoded signal with repetitive elements, uniquely associated with a target transponder. Periodically, each transponder correlates its coded ID against a possible inquiry signal, determining frequency, phase and framing in the process. Upon a match, the transponder transmits a synthesized response coherent with the received signal. The locator integrates multiple cyclical response elements, allowing low-power transmissions from the transponder. The locator correlates the integrated response, determines round-trip Doppler shift, time-of-flight, and then computes the distance and angle to the transponder. The transponder can be wearable, bionically implanted, or attached to, or embedded in, some object.

Abstract: A radar having a high time and high spatial resolution and being capable of performing volume scanning with an inexpensive and simple structure, while enabling reduction is size and weight. A radar (50) is provided with an antenna unit (51) including a radio wave lens antenna device, which has a spherical transmission radio wave lens (2), a spherical reception radio wave lens (3), a primary radiator (4) arranged at a focal point of the radio wave lens (2), and a primary radiator (5) arranged at a focal point of the radio wave lens (3). The primary radiators (4, 5) pivot in an elevation direction about an axis connecting center points of the radio wave lenses (2, 3) and pivot in an azimuthal direction about an axis orthogonal to the axis connecting the center points of the radio wave lenses (2, 3).

Abstract: A spread spectrum radar apparatus includes: a transmission unit which generates a spread signal that is a spectrum-spread signal, using a first oscillator signal, a second oscillator signal, and a transmission PN code, and which emits the spread signal as a detection radio wave; and a reception unit which receives, as a reception signal, the detection radio wave reflected from an object, and which generates an intermediate frequency signal by despreading the reception signal based on the first oscillator signal and a reception PN code obtained by delaying the transmission PN code.

Abstract: The present invention relates to a method for storing measurements of a given type made by a radar, each measurement having been made at a position in a given coordinate system. The method comprises a step of accessing a structured data storage space, each location of which is addressable by a pair of positive integers and each location of which is able to store at least one evolution profile of the measurements of the given type as a function of altitude. It also comprises a meshing step which associates a ground position with a pair of positive integers allowing a location to be addressed. The method also comprises a step of modifying the content of the location with the pair of integers as its address by storing there an evolution profile such that for each ground position sufficiently close to the position associated with the pair and for which a measurement has been made at a certain altitude, the evolution profile provides approximately the measurement made at this altitude.

Abstract: A weather radar system coupled to a weather radar antenna, including a receive circuit for receiving radar returns received by the antenna and a processor for summing portions of the radar return data to obtain a null response. The null response is utilized to determine presence of terrain.

Abstract: A terrain awareness and warning system includes electronics for receiving radar returns and providing terrain and/or obstacle alerts or warnings in response to the radar returns. The electronics receives information from a database and the information is utilized to suppress false alerts or warnings.

Abstract: A method, system and computer program is disclosed for reducing range and angular ambiguities in a target data matrix output from a real beam monopulse radar sensor within a single beam for use in terrain morphing applications employed by brownout take-off and landing aid systems. One or more range bins are calculated to selectively determine one or more range segments from one or more targets of interest. Range resolution enhancement processing is employed to the selectively determined one or more range segments to obtain a range of target scatter locations. A monopulse angle bin is estimated from the obtained range of target scatter locations and one or more control inputs. Elevation and azimuth angular binning is applied to the estimated monopulse angle bin to obtain a smaller coverage area among one or more possible target areas.

Abstract: A method for processing received radar returns of a radiated wide-band arbitrary waveform in a wide-band radar processing system using spectral processing. The received wide-band radar returns are undersampled by using a first sampling rate to obtain an undersampled digital wide-band radar waveform. Spectral processing is performed on the power spectrum of the undersampled digital wide-band radar waveform in order to obtain a discrete ripple frequency power spectrum of the undersampled digital wide-band radar waveform. Ripple frequencies indicating radar targets are located in the discrete ripple frequency power spectrum of the undersampled digital wide-band radar waveform. A radar receiver, a digital wide-band radar processing system and a computer program product.

Abstract: A processor operatively coupled to a speed sensor adapted to generate a measure of a longitudinal speed of a vehicle on a roadway, and to a source of a measure of yaw rate of the vehicle, provides for selecting a most likely roadway model of a plurality of different roadway models and for outputting a corresponding associated at least one curvature parameter as an estimate of curvature of the roadway, wherein the processor incorporates a plurality of curvature estimators associated with the corresponding plurality of different roadway models.

Abstract: In one embodiment, the disclosure relates to a method for estimating and predicting a target emitter's kinematics, the method including the steps of: (a) passively sampling, at a first sampling rate, an emitter signal to obtain at least one passively measured signal attribute for estimating the target kinematics; (b) inputting the passively measured signal attribute to an estimator at a first sampling rate; (c) determining a radar duty cycle for active radar measurements as a multiple of the first sampling rate, the multiple defining a duration between radar transmissions; (d) directing a radar system to make active target measurements at the determined duty cycle; (e) inputting to the estimator the active target measurements at the determined duty cycle, while continuously inputting the passively measured signal attributes.

Abstract: A field unit for warning of a danger of collision between an aircraft and an obstacle, in particular a topographical ground obstacle or an obstacle formed by a mast, building or aerial cable structure, comprises a multi-part tubular mast having devices for fixing a solar panel and a radar antenna; an elongate radar antenna in an environment-protective casing, which, with an electronics unit, forms a radar system for synthesized radar detection of an aircraft in a radar coverage area; a central processing unit for identifying on the basis of information from the radar system an aircraft which is in a zone of the radar coverage area and which on the basis of radar information such as direction, distance and/or speed computes a collision danger area; and a high-intensity light system and radio transmitter system that can be activated by the central processing unit upon detection of an aircraft in a collision danger area.