Abstract: The present invention relates to a method for determining position and velocity of targets from signals scattered by the targets. One uses a first and a second station comprising transmitter/receiver (s1,s2) of electromagnetic or acoustic signals and carries out mono-static measurements (M1,M2) from each station, and also a bi-static measurement between the stations (B12), and calculates first through the two mono-static measurements a number of target candidates with 2-dimensional position and 2-dimensional velocity, whereupon these are tested against the result of the bi-static measurement and the target candidates which are found In all measurements with suitable error margins are retained.

Abstract: The present invention relates to a system for using signals scattered by targets to determine position and velocity for each of the targets and comprises a set of transmitters and receivers of electromagnetic or acoustic signals, said transmitters and receivers dispersed to known points. Each pair of transmitter and receiver, mono-static or bi-static, is named a measuring facility. The ranges of the transmitters are chosen so that a target at an arbitrary point within the position space can be measured via scattering in the target by at least four, but preferably many more, measuring facilities.

Abstract: A vehicle control apparatus includes an obstruction detection unit for measuring a headway distance until an obstruction existing ahead of the vehicle by means of a radar device, a unit for performing vehicle control or alarm control on the basis of the headway distance, a unit for detecting detection performance of the obstruction detection means in a vehicle in which the obstruction detection unit is used to perform two or more controls containing the vehicle control or alarm control, and a unit for controlling to stop operation of the vehicle control or alarm control in accordance with the detection performance individually.

Abstract: A bistatic radar system (100), method and computer program (178) are provided for mapping of oceanic surface conditions. Generally, the system (100) includes at least one transmitter (102) and at least one receiver (106) located separate from one another, and each having a local oscillator locked to a Global Positioning System (GPS) signal received by a GPS synchronization circuit (134) to provide the necessary coherency between the transmitted and received signals. Preferably, the present invention enables an existing backscatter radar systems to be quickly and inexpensively upgraded to a bistatic radar system (100) through the addition of a transmitter (102) and/or receiver (106) separate from the backscatter radar system, the GPS circuit (134), and use of the computer program (178) and method of the present invention.

Abstract: An in-vehicle pulse radar device includes: an oscillator that generates an electromagnetic wave; a transmission amplifier that transmits the electromagnetic wave generated by the oscillator toward a target substance; an antenna that receives the reception electromagnetic wave reflected by the target substance to output data; reception amplifiers; a reception antenna; an A/D converter; and a signal processing device that pre-sums data which is sampled on the basis of the data from the A/D converter for each of distance gates, subjects the pre-summed data which is a result of the pre-summing process to an FFT process, and obtains a distance between a subject vehicle and the target substance and a relative speed therebetween in accordance with the spectrum frequency and the amplitude information which are a result of the FFT process.

Abstract: To measure the absolute speed of a body 100 moving relative to the ground 33 using an onboard speed sensor 1, a radar wave is transmitted towards the ground by an antenna with a wide aperture angle. The wave reflected by a reflecting obstacle on the ground and the transmitted wave are mixed and the frequency content of the low frequency signal obtained is determined. The speed of the moving object and the height of the transmitter and receiver antennas above the ground can then be measured by adjusting a theoretical curve to the time-varying evolution of the Doppler frequency corresponding to the reflecting obstacle.

Abstract: The crossover detection method of a radar apparatus according to the present invention calculates distance/relative velocity information at a multitude of different clock times, using a beat signal; calculates predicted distance/relative velocity information indicating distance/relative velocity, respectively, of a target after a prescribed time has elapsed; calculates predicted distance/relative velocity errors by subtracting the calculated distance/relative velocity information from the calculated predicted distance/relative velocity information, respectively; calculates degree of similarity information, based on the predetermined average predicted distance/relative velocity errors and the calculated predicted distance/relative velocity errors; and determines whether there is crossover, based on the above information.

Abstract: A radar signal processing unit comprises a Fourier transform section 1 for executing Fourier transform of the received signal to a frequency signal, a frequency domain power calculation section 2 for calculating a power spectrum of electric power for each frequency from the frequency signal, an abnormal echo removal section 3 for determining the abnormal echo based on the power value of the power spectrum and outputting only the power spectrum not corresponding to the abnormal echo, an incoherent processing section 4 for performing incoherent integration of only the power spectrum not corresponding to the abnormal echo and averaging, and a signal detection section 5 for calculating the physical quantity of the atmosphere from the incoherent-integrated power spectrum.

Abstract: A compact, autonomous motion detecting and alerting system alerts to the movement of objects of interest. Mounted on an environmentally sealed PC board are a transceiver such as a CW radar front-end, connectors, signal processors and a communications device. The system provides early warning of movement of an ice sheet or rubble field via the communication device that may be a cellular telephone. This system is mounted proximate the target surface under observation, oriented at pre-specified offset angles both laterally and in elevation. The target is illuminated and energy reflected therefrom is mixed with a portion of the transmitted signal to produce a difference frequency signal that is processed to establish existence of motion within a pre-specified velocity range. Upon verification of motion, notification is sent to a responsible authority. An autonomous or semi-autonomous power source and integral power management function may be incorporated on the same PC board.

Abstract: A radar speed measurement device (10) comprising a display (12) for displaying a target speed, a radar emitter (14) for emitting radar waves toward a target, a radar receiver (16) for receiving radar waves reflected from the target, an analog to digital converter (18) for producing digital signals associated with the radar waves, and a signal processor (20) for determining the target speed by analyzing the digital signals. The device (10) can also calculate statistics associated with the target and further comprises a statistical processor (22) for calculating the statistics. The device (10) can operate in either of two modes. A speed mode is preferably used to determine the target speed, when the target is a race car or any other object. A baseball statistics mode is preferably used to determine the target speed, when the target is a baseball thrown by a pitcher.

Abstract: In a target merging process in a radar ranging device, determination of continuity is accurately performed and output processing of newly appearing targets is performed rapidly. The current target position (data prior to merging) is calculated (S1), and a predicted position is calculated (S2). The continuity of targets whose previous position and current position satisfy predetermined conditions (S3 to S5) is determined (S6 to S7). After the data prior to merging is stored in a buffer (S9), the merging process is performed. By storing the data prior to merging in the buffer, continuity is determined for each detected target and, therefore, even if the position of a target changes after merging, subsequent determination of continuity can be performed accurately.

Abstract: When a reflective wave reflected from a preceding object is received, the reflective wave being of an original radar beam scanned at a variable vertical angle, the vertical angle is detected, an absolute speed of the preceding object is calculated based on a vehicle speed and a relative speed calculated from the reflective wave, and accordingly a driving environment is determined based on the vertical angle and the absolute speed.

Abstract: An outdoor microwave transceiver intrusion detector that alternately transmits pulses of RF energy at two different frequencies and uses range and direction of travel information derived from the phase of the two Doppler responses to optimize the signal processing and apply range dependent thresholds. The time delay between the onset of the transmitted pulse and the sample of the Doppler response is controlled to provide an accurate range cutoff. The two frequencies are selected so that the difference in phase of the Doppler response at the two frequencies increases from zero to ninety degrees as the target goes from the Transceiver to the maximum range. Digital signal processing is used to measure the difference in phase of the two Doppler responses and translate this information into location of the target. The location information is used to create a number of range bins.

Abstract: An FM-CW radar processing system pairs up peaks obtained by fast-Fourier transforming a beat signal occurring on an up portion and a down portion of a triangular-shaped FM-CW wave, calculates a distance or relative velocity with respect to a target object based on the peak signal in the up portion and the peak signal in the down portion obtained by the pairing, and compares the distance or relative velocity, obtained after changing the modulating signal for the FM-CW wave, with the distance or relative velocity obtained before changing the modulating signal. If the distance or relative velocity differs before and after changing the modulating signal, the pairing is judged to be mispairing.

Abstract: The invention detects a ghost occurring due to mispairing, reflections from a wall, or the like, and improves the ability of a radar to track targets when actual relative velocity changes by more than a certain value. If a stationary target is present within a prescribed region centered about a moving target, the stationary target is excluded from output data by determining it as being a target resulting from mispairing due to the detection of guardrail posts or similar structures. Further, a moving target that is expected to collide with an eligible target is also excluded from the output data by determining it as being a target resulting from mispairing due to the detection of a target having many reflecting points. For a moving target showing an unlikely relative velocity, pairing with some other peak is attempted by determining the moving target as being a target resulting from mispairing due to the detection of a plurality of moving targets moving in the same direction.

Abstract: Disclosed is a method of storing data for temporarily storing a plurality of detected data in a data buffer or the like included in a radar used for a vehicle. The radar detects signals reflected from a plurality of target objects so as to obtain a plurality of detected data, and detects the presence of the plurality of target objects on the basis of the plurality of detected data.

Abstract: A method for tracking a target vehicle through a curve in a roadway is disclosed. The method includes measuring an azimuth angle between the target vehicle and a host vehicle, calculating a relative velocity between the target vehicle and the host vehicle, developing a theoretical relationship, wherein the relationship is a function of the measured azimuth angle and the measured relative velocity, and comparing the developed theoretical relationship with measured relationship between the azimuth angle and the relative velocity. Further, the target vehicle is determined to be in the same lane or path of the host vehicle by evaluating how well the developed theoretical relationship fits the with the measured azimuth angle and calculated relative velocity. Therefore, the present invention determines the path of a target vehicle without relying on inaccurate conventional methods based on the yaw rate of the host vehicle.

Abstract: A vehicle-mounted radar apparatus which periodically derives and registers successive momentary position values for a target object such as a preceding vehicle based on received reflected radio waves and derives final lateral position data by smoothing the momentary position data, judges when a degree of scattering of the registered momentary position values exceeds a first predetermined level and in that case derives corrected position data based on differences between envelope curve line values which are generated based on local extreme values of the momentary position data, and performs smoothing of the corrected position data instead of the momentary position data, to obtain the final lateral position data. If the target object is not estimated to be located directly ahead of the host vehicle along a straight route, the corrected position data are adjusted in accordance with relative positions and orientations of the target object and host vehicle.

Abstract: A method for calculating a center frequency and a bandwidth for a radar doppler filter is herein described. The center frequency and bandwidth are calculated to provide radar performance over varying terrain and aircraft altitude, pitch, and roll. The method includes receiving an antenna mounting angle, a slant range, and velocity vectors in body coordinates, calculating a range swath doppler velocity, a track and phase swath bandwidth, and a phase swath doppler velocity. The method continues by calculating a range swath center frequency based on the range swath doppler velocity, calculating a phase swath center frequency based on the phase swath doppler velocity, and calculating a level and verify swath bandwidth based upon the track and phase swath bandwidth.

Abstract: A method and apparatus for obtaining measurements, on a spacecraft that employs a transceiver, at intervals that are shorter than the telemetry frame duration for use in correcting ground-based Doppler measurements so as to remove the effects of drift in the spacecraft oscillator frequency reference. Samples of navigation counters on the spacecraft that supply information that may be used to compare the uplink frequency with the downlink frequency at the spacecraft are triggered at intervals that are shorter than the duration of a telemetry frame; the samples are then included in a telemetry frame and are time tagged after they are received on the ground; the time tagged samples are then used to calculate precise two-way Doppler measurements.

Abstract: A phase processor is disclosed which is configured to receive processed radar return data from a left radar channel, a right radar channel, and an ambiguous radar channel. The phase processor comprises a plurality of phase detectors each with an input and a reference input. The phase detectors are configured to determine a phase difference between radar return data received at the input and radar return data received at the reference input.

Abstract: A series of police doppler single mode radars and a multimode police doppler radar, all with direction sensing capability are disclosed. A quadrature front end which mixes received RF with a local oscillator to generate two channels of doppler signals, one channel being shifted by an integer multiple of 90 degrees in phase relative to the other by shifting either the RF or the local oscillator signal being fed to one mixer but not the other. The two doppler signals are digitized and the samples are processed by a digital signal processor programmed to find one or more selected target speeds. Single modes disclosed are: stationary strongest target; stationary, fastest target; stationary, strongest and fastest targets; moving, strongest, opposite lane; moving, strongest, same lane; moving, fastest, opposite lane; moving, fastest and strongest, opposite lane; moving, fastest, same lane; moving fastest and strongest, same lane.

Abstract: An FMCW radar is provided which may be employed in automotive anti-collision or radar cruise control systems. In a distance measuring mode, only one of channels is used to sample a beat signal continuously, thereby allowing a sampling frequency to be increased up to Nc times that in an azimuth measuring mode and a sweep time in which a transmit signal sweeps in frequency upward and downward cyclically to be minimized. This causes half the sampling frequency to be higher than a frequency component arising sufficiently from a distant target present outside a preset radar range, thereby eliminating an error in detecting the distant target as being located inside the preset radar range.

Abstract: A system for processing radar data from two or more areas of interest is provided, such as for simultaneously processing vehicle speeds in the opposite lane in front of the patrol vehicle and in the opposite lane behind the patrol vehicle. The system includes an antenna signal processor that receives radar data from one or more radar antennae and generates speed data for a first vehicle travelling in a first direction relative to a radar observation point and a second vehicle travelling in a second direction relative to the radar observation point. A display generator system receives the speed data and user-entered display control data, and generates user-readable display data based on the speed data and the user-entered display control data.

Abstract: A self-modulating, remote, moving target detector for intrusion alarms, vehicle detection, and remote speed and distance measurement that includes a remote continuous wave radar transceiver that is used to detect moving targets. The same frequency used for the radar transmission is modulated in a continuous manner in order to transmit radar data concerning a moving target to a remote location away from the radar transceiver. The transceiver oscillator is self-modulated by the reflected signal received from a moving target in the transceiver and retransmitted such that the primary radar signal becomes the information carrier concerning the moving target, which is received remotely, in order to activate an alarm or a display system showing the moving target. The system could be utilized with any frequency from audio to light, with RF and microwave of primary interest.

Abstract: The invention provides an object recognition apparatus that removes virtual images without detecting a roadside object. When a predetermined vehicle is currently running on a lane, a detection area, outside of the currently running lane, is designated to include a first area and an assumed ghost area therein. The first area is enclosed by a boundary of the detection area, a boundary of the assumed ghost area adjacent thereto, and a boundary on the currently running lane whose distance is traveled by the vehicle during one control cycle. The invention detects an object for the first time in the assumed ghost area, not in the first area. When the object travels with a distance and a speed of a target vehicle, it is determined to be a ghost to be deleted.

Abstract: The determination of separation (R) and relative speed (v) of at least one object which is distant from an observation point can be achieved by sending electromagnetic signals from the observation point, with a frequency shift over a modulation range (fSweep), in the form of signal segments (A, B) during a measuring interval, with a frequency separation (fShift) from each other which are transmitted alternately, the echo signals from which are detected after reflecting from the object. The phase difference (&Dgr;&phgr;) of the echo signals arising from each signal segment (A, B) is detected. Said determination occurs with short reaction time and high precision whereby the signal segments (A, B) are transmitted with a stepwise shift each time by a frequency step (fIncr) over the modulation range (fSweep) and at least one sampled value for determination of the phase difference (&Dgr;&phgr;) for each signal segment is taken.

Abstract: A HF radar uses the same antenna array (414, 424, 424′, 424′) for both transmission (TX) and reception (RX). Each radiating element of the array may be driven by its own local transmitter and may have its own local receiver, both being connected to a central processor via fiber optic cables conveying digital data to the local transmitter relating to element energization in the TX mode and data representing signals received by the radiating elements in the RX mode. Each antenna element may have its own TX/RX unit, or a single TX/RX unit may serve two or more radiating elements. Each radiating element may comprise a skeletal pyramidal dipole mounted at ground level.

Abstract: In a method and apparatus for controlling the distance of a vehicle to a vehicle traveling ahead, in which the distance and the relative velocity of the vehicle traveling ahead are measured and the distance, in a distance control mode, is controlled by accelerating or decelerating the vehicle to a preestablished setpoint distance, wherein the deceleration permitted by the distance control process is limited and, in situations in which the setpoint distance cannot be maintained at this limited deceleration, the transition is made from the distance control process to a process limiting the distance to a minimum distance which is smaller than the setpoint distance, and the vehicle, after reaching the minimum distance, is further decelerated, so that the distance once again increases to the setpoint distance.

Abstract: A sensor array with a pulse echo radar system with which a carrier signal of a microwave transmitter oscillator is transmitted in the form of pulses with a specified pulse repetition frequency in a transmission window. This radar signal is reflected from a target object and the position of the target object is calculated in a mixer from the times of transmission of the pulse to the arrival of the reflected radiation. An array of several transmitter and receiver units with switches are constructed in which the stochastic pulse sequences of each transmission window in each receiver branch are known and the transmitter and receiver units are linked to one another so that in each of the receiver branches the stochastic pulse sequences of each transmission window are detected separately and thereby the cross echoes may also be analyzed.

Abstract: In a method for HPRF-radar measurement of the range and Doppler frequency of at least one target, a transmit signal is generated which consists of two pulse sequences that are interleaved on a pulse to pulse basis, and have the same pulse repetition frequency PRF and the same transmit frequency. The pulses of a first one of the two pulse sequences have a linearly increasing phase value with a fixed phase difference &phgr;1n (greater than zero) from pulse to pulse with &phgr;1n≧0, while the pulses of the second pulse sequence have a linear increasing phase value with a fixed phase difference &phgr;2n which differs from &phgr;1n. The two received base band signals of each individual pulse sequence are Fourier transformed, and the amplitude peaks of the resulting two Fourier spectra are determined.

Abstract: An inventive frequency modulated continuous wave (FMCW) radar system realizes both of a quick detection of higher relative speed provisional target and a sure detection of smaller relative speed provisional target. The number of detection cycles used for a paring validity check (a test to see if a detected target or a pair of frequencies is an actual target or a pair for an actual target) is set in response to the relative velocity.

Abstract: The present invention relates to a radar system having means (12) for producing a code, means (18) for modulating a transmission signal in a transmit branch, using the code, means (32) for delaying the code, means (20) for modulating a signal in a receive branch, using the delayed code, and means (26) for mixing a reference signal with a receiving signal, the modulation of one of the signals being performed by an amplitude modulation (ASK; “amplitude shift keying”) and the modulation of the other signal by a phase modulation (PSK; “phase shift keying”). Furthermore, a radar system is proposed in which blanking of phase transitions is provided. The present invention also relates to methods which may advantageously be carried out, using the radar systems according to the present invention.

Abstract: A radar performs accurate and appropriate pairing even if peaks of approximately identical signal intensities or even if a plurality of peak groups having identical representative beam bearings exist in the frequency spectrum. First, the peak frequency of a peak which appears in the frequency spectrum is determined for each of an up-modulating interval and a down-modulating interval in predetermined beam bearings, and signal-intensity profiles in the beam bearings are extracted with regard to a plurality of beam portions which are adjacent to the beam bearings. Next, the correlation level between the signal-intensity profiles at the up-modulating interval and the down-modulating interval is determined, and pairing is performed in sequence starting from the profiles having a higher correlation level.

Abstract: A sensor front end is disclosed that is able to discriminate objects based on their range from the sensor. The sensor includes an antenna that transmits a sensor signal and, if an object is present receives a reflected signal therefrom. A pulsed oscillator provides a pulsed first signal having a first frequency and phase, and wherein the pulsed oscillator provides the pulsed first signal for a predetermined pulse duration and with a predetermined pulse repetition frequency. The pulsed oscillator provides the pulsed first signal to a first input port of a dual mode mixer that is further coupled to the antenna via a second port. The dual mode mixer transmits a portion of the pulsed first signal from the first input port to the second port and thus to the antenna to be transmitted as the sensor signal. In addition, the dual mode mixer uses a portion of the first signal to mix with the received reflected signal. The dual mode mixer then provides a mixed signal as an output at a third port.

Abstract: When a new target is detected, if it is determined that the distance difference between the newly detected target and the previously detected target is within a predetermined range, the difference between the relative velocity of the newly detected target and the relative velocity of the previously detected target is obtained to determine whether the difference is greater than a predetermined value &Dgr;Va, and when the difference is greater than the predetermined value, it is determined that the new target is a target obtained as a result of mispairing.

Abstract: The invention detects a ghost occurring due to mispairing, reflections from a wall, or the like, and improves the ability of a radar to track targets when actual relative velocity changes by more than a certain value. If a stationary target is present within a prescribed region centered about a moving target, the stationary target is excluded from output data by determining it as being a target resulting from mispairing due to the detection of guardrail posts or similar structures. Further, a moving target that is expected to collide with an eligible target is also excluded from the output data by determining it as being a target resulting from mispairing due to the detection of a target having many reflecting points. For a moving target showing an unlikely relative velocity, pairing with some other peak is attempted by determining the moving target as being a target resulting from mispairing due to the detection of a plurality of moving targets moving in the same direction.

Abstract: A police radar and/or laser detector senses radiant electromagnetic signals (e.g. radar, laser) characteristic of a police traffic surveillance device and responds thereto with a displayed and/or audible alert. During periods when no alert is necessary, the detector senses and displays, in numeric or bar graph form, vehicle parameters, such as sound pressure level and acceleration. In addition, calculations based on acceleration provide 0-60 m.p.h. time and quarter mile time. Thereby, the detector enhances information available to the driver without the inconvenience, expense, and clutter of multiple displays.

Abstract: A Doppler radar apparatus includes a first oscillator for generating a first sweep signal to repeatedly sweep a predetermined frequency range periodically; a second oscillator for generating a second sweep signal having sweep properties identical to those of the first sweep signal, the second oscillator 41b starting sweep before the first oscillator finishes frequency sweep; a power combiner for combining the first and second sweep signals to generate a transmission signal; a switch for receiving, as inputs, the first and second sweep signals, and switching an output between the first and second sweep signals synchronously with the timing when sweep with each of the first and second sweep signals is terminated; and a mixer for mixing a reception signal coming from a part of the transmission signal reflected in a target and received, and an output signal from the switch with each other to produce an output signal from the mixer.

Abstract: In an FM-CW radar system, regarding peaks appearing in the frequency spectrum of a beat signal in an FM-CW radar, groups of consecutive peaks in beam bearings within a predetermined frequency difference are regarded as being caused by reflected waves from a single target, and based on a combination of a peak group in an up-modulating interval and a peak group in a down-modulating interval, a relative distance to a target and its relative speed are determined.

Abstract: The present invention relates to a radar device and, particularly, to a radar device mounted on a vehicle to be used for a collision alarm and the like. The invention provides a radar device that has a unit for removing the FMAM noise without lowering the signal detection sensitivity. The radar device transmits a frequency modulation signal by switching the frequency modulation signal with a first switching signal, receives a signal reflected from a target object, switches the reception signal with a second switching signal, mixes the switched reception signal with the transmission signal, and further mixes the mixed signals with a third switching signal thereby to obtain a beat signal. The radar device obtains a distance to the target object and a relative speed of the target object from the beat signal.

Abstract: When a reflective wave reflected from a preceding object is received, the reflective wave being of an original radar beam scanned at a variable vertical angle, the vertical angle is detected, an absolute speed of the preceding object is calculated based on a vehicle speed and a relative speed calculated from the reflective wave, and accordingly a driving environment is determined based on the vertical angle and the absolute speed.

Abstract: As to a beat signal of a received wave, for instance, a plurality of FFT-based frequency spectra of every FM rise zone are accumulated in an accumulation unit. A judgment unit judges a valley section from the plurality of frequency spectra accumulated. A peak frequency extraction unit acquires, as beat frequencies of different targets, respective beat frequencies of peak sections located at both sides of the valley sections judged.

Abstract: A system for processing radar data from two or more areas of interest is provided, such as for simultaneously processing vehicle speeds in the opposite lane in front of the patrol vehicle and in the opposite lane behind the patrol vehicle. The system includes an antenna signal processor that receives radar data from one or more radar antennae and generates speed data for a first vehicle travelling in a first direction relative to a radar observation point and a second vehicle travelling in a second direction relative to the radar observation point. A display generator system receives the speed data and user-entered display control data, and generates user-readable display data based on the speed data and the user-entered display control data.

Abstract: A device for non-contractual measurement of the speed of an object moving over a surface comprises a means for radiating a signal of fixed frequency at an angle onto the surface in or against the direction of motion, said angle being variable by the movement of the object, and for receiving a Doppler-shifted signal reflected at the surface. A means is provided for combining a plurality of reflected Doppler-shifted signals, which are received in temporal succession, so as to produce a combined spectrum. The device for non-contractual speed measurement additionally comprises a means for detecting from the combined spectrum the spectral portion having the highest or lowest frequency and exceeding a predetermined signal power, and a means for deducing the speed from the frequency of the detected spectral portion.

Abstract: A system and method for identifying the position of an airborne platform on a flight path includes at least three radar transceivers that are directed along respective beam paths to generate return signals. Each of the return signals respectively indicate a speed and a direction of the platform relative to points on the surface of the earth. A computer uses the return signal to establish a ground speed, an altitude and a direction of flight for the platform. This information is then used to identify the position of the platform on its flight path. Additionally, the system can include a last known position, or a site-specific radar clutter model, to establish a start point for the platform. The computer can then calculate the position of the platform relative to the start point.

Abstract: A radar system and a characteristic adjustment method for the radar system are provided, in which a control voltage waveform of a voltage controlled oscillator for frequency-modulating a sending signal can be set in a short time without increasing the required amount of memory. In adjusting time-varying characteristics of a voltage signal for frequency modulation on a voltage controlled oscillator determining a sending frequency, the time-varying characteristics of the voltage signal for frequency modulation are adjusted to optimize a form of a protrusion in signal intensity included in a frequency spectrum of a beat signal.

Abstract: In a target merging process in a radar ranging device, determination of continuity is accurately performed and output processing of newly appearing targets is performed rapidly. The current target position (data prior to merging) is calculated (S1), and a predicted position is calculated (S2). The continuity of targets whose previous position and current position satisfy predetermined conditions (S3 to S5) is determined (S6 to S7). After the data prior to merging is stored in a buffer (S9), the merging process is performed. By storing the data prior to merging in the buffer, continuity is determined for each detected target and, therefore, even if the position of a target changes after merging, subsequent determination of continuity can be performed accurately.

Abstract: A spread spectrum radar system, characterized in that the receive radar signal is mixed down to baseband and applied to leak cancellation means for subtracting therefrom an attenuated delayed version of the transmit radar signal to provide a reflected receive radar signal with improved signal-to-noise ratio for further processing and to prevent receiver saturation. The radar allows the capture of the range and speed of identified targets, and facilitates .a determination of the target's direction. It exhibits an inherent immunity to electromagnetic interference, and is relatively undetectable by radar detectors. The system is easily reprogrammable for different range resolutions and permits Doppler processing to be independent of the angle between radar signal and the track of the target.

Abstract: A method and apparatus for obtaining measurements, on a spacecraft that employs a transceiver, at intervals that are shorter than the telemetry frame duration for use in correcting ground-based Doppler measurements so as to remove the effects of drift in the spacecraft oscillator frequency reference. Samples of navigation counters on the spacecraft that supply information that may be used to compare the uplink frequency with the downlink frequency at the spacecraft are triggered at intervals that are shorter than the duration of a telemetry frame; the samples are then included in a telemetry frame and are time tagged after they are received on the ground; the time tagged samples are then used to calculate precise two-way Doppler measurements.