Systems using the reflection or reradiation of radio waves

GPHYSICS G01Measuring instruments G01SRADIO DIRECTION-FINDING RADIO NAVIGATION DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES ANALOGOUS ARRANGEMENTS USING OTHER WAVES

G01S13/00Systems using the reflection or reradiation of radio waves

G01S13/003Bistatic radar systems; Multistatic radar systems G01S13/006Theoretical aspects G01S13/02Systems using reflection of radio waves G01S13/0209Systems with very large relative bandwidth, i.e. larger than 10 % G01S13/0218Very long range radars G01S13/04Systems determining the presence of a target G01S13/06Systems determining position data of a target G01S13/08Systems for measuring distance only G01S13/10using transmission of interrupted pulse modulated waves G01S13/103particularities of the measurement of the distance G01S13/106using transmission of pulses having some particular characteristics G01S13/12wherein the pulse-recurrence frequency is varied to provide a desired time relationship between the transmission of a pulse and the receipt of the echo of a preceding pulse G01S13/14wherein a voltage or current pulse is initiated and terminated in accordance respectively with the pulse transmission and echo reception G01S13/16using counters G01S13/18wherein range gates are used G01S13/20whereby multiple time-around echoes are used or eliminated G01S13/22using irregular pulse repetition frequency G01S13/222using random or pseudorandom pulse repetition frequency G01S13/225with cyclic repetition of a non-uniform pulse sequence G01S13/227with repetitive trains of uniform pulse sequences, each sequence having a different pulse repetition frequency G01S13/24using frequency agility of carrier wave G01S13/26wherein the transmitted pulses use a frequency- or phase-modulated carrier wave G01S13/28with time compression of received pulses G01S13/282using a frequency modulated carrier wave G01S13/284using coded pulses G01S13/286frequency shift keyed G01S13/288phase modulated G01S13/30using more than one pulse per radar period G01S13/32using transmission of continuous unmodulated waves, amplitude-, frequency- or phase-modulated waves G01S13/325using transmission of coded signals G01S13/34using transmission of frequency-modulated waves and the received signal, or a signal derived therefrom, being heterodyned with a locally-generated signal related to the contemporaneous transmitted signal to give a beat-frequency signal G01S13/341wherein the rate of change of the transmitted frequency is adjusted to give a beat of predetermined constant frequency G01S13/342using sinusoidal modulation G01S13/343using sawtooth modulation G01S13/345using triangular modulation G01S13/346using noise modulation G01S13/347using more than one modulation frequency G01S13/348using square or rectangular modulation G01S13/36with phase comparison between the received signal and the contemporaneously transmitted signal G01S13/38wherein more than one modulation frequency is used G01S13/40wherein the frequency of transmitted signal is adjusted to give a predetermined phase relationship G01S13/42Simultaneous measurement of distance and other co-ordinates G01S13/422sequential lobing G01S13/424Stacked beam radar G01S13/426Scanning radar G01S13/428within the pulse scanning systems G01S13/44Monopulse radar G01S13/4409HF sub-systems particularly adapted therefor G01S13/4418with means for eliminating radar-dependent errors in angle measurements G01S13/4427with means for eliminating the target-dependent errors in angle measurements G01S13/4436with means specially adapted to maintain the same processing characteristics between the monopulse signals G01S13/4445amplitude comparisons monopulse G01S13/4454phase comparisons monopulse G01S13/4463using phased arrays G01S13/4472with means specially adapted to airborne monopulse systems G01S13/4481Monopulse hybrid systems G01S13/449Combined with MTI or Doppler processing circuits G01S13/46Indirect determination of position data G01S13/48using multiple beams at emission or reception G01S13/50Systems of measurement based on relative movement of target G01S13/505using Doppler effect for determining closest range to a target or corresponding time G01S13/52Discriminating between fixed and moving objects or between objects moving at different speeds G01S13/522using transmissions of interrupted pulse modulated waves G01S13/524based upon the phase or frequency shift resulting from movement of objects, with reference to the transmitted signals G01S13/5242with means for platform motion or scan motion compensation G01S13/5244Adaptive clutter cancellation G01S13/5246post processors for coherent MTI discriminators G01S13/5248combining a coherent MTI processor with a zero Doppler processing channel and a clutter mapped memory G01S13/526performing filtering on the whole spectrum without loss of range information G01S13/5265IF cancellers G01S13/528with elimination of blind speeds G01S13/53performing filtering on a single spectral line and associated with one or more range gates with a phase detector or a frequency mixer to extract the Doppler information G01S13/532using a bank of range gates or a memory matrix G01S13/534based upon amplitude or phase shift resulting from movement of objects, with reference to the surrounding clutter echo signal G01S13/536using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves G01S13/538eliminating objects that have not moved between successive antenna scans G01S13/56for presence detection G01S13/58Velocity or trajectory determination systems Sense-of-movement determination systems G01S13/581using transmission of interrupted pulse modulated waves and based upon the Doppler effect resulting from movement of targets G01S13/582adapted for simultaneous range and velocity measurements G01S13/583using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets G01S13/584adapted for simultaneous range and velocity measurements G01S13/585processing the video signal in order to evaluate or display the velocity value G01S13/586using, or combined with, frequency tracking means G01S13/587using optical means G01S13/588deriving the velocity value from the range measurement G01S13/589measuring the velocity vector G01S13/60wherein the transmitter and receiver are mounted on the moving object G01S13/605using a pattern, backscattered from the ground, to determine speed or drift by measuring the time required to cover a fixed distance G01S13/62Sense-of-movement determination G01S13/64Velocity measuring systems using range gates G01S13/66Radar-tracking systems Analogous systems where the wavelength or the kind of wave is irrelevant G01S13/68for angle tracking only G01S13/685using simultaneous lobing techniques G01S13/70for range tracking only G01S13/72for two-dimensional tracking G01S13/723by using numerical data G01S13/726Multiple target tracking G01S13/74Systems using reradiation of radio waves G01S13/75using transponders powered from received waves G01S13/751wherein the responder or reflector radiates a coded signal G01S13/753using frequency selective elements G01S13/755using delay lines G01S13/756using a signal generator for modifying the reflectivity of the reflector G01S13/758using a signal generator powered by the interrogation signal G01S13/76wherein pulse-type signals are transmitted G01S13/762with special measures concerning the radiation pattern G01S13/765with exchange of information between interrogator and responder G01S13/767Responders; Transponders G01S13/78discriminating between different kinds of targets, e.g. IFF-radar G01S13/781Secondary Surveillance Radar [SSR] in general G01S13/782using multimoding or selective addressing G01S13/784Coders or decoders therefor; Degarbling systems; Defruiting systems G01S13/785Distance Measuring Equipment [DME] systems G01S13/787co-operating with direction defining beacons G01S13/788Coders or decoders therefor; Special detection circuits G01S13/79Systems using random coded signals or random pulse repetition frequenties G01S13/82wherein continuous-type signals are transmitted G01S13/825with exchange of information between interrogator and responder G01S13/84for distance determination by phase measurement G01S13/86Combinations of radar systems with non-radar systems G01S13/862Combination of radar systems with sonar systems G01S13/865Combination of radar systems with lidar systems G01S13/867Combination of radar systems with cameras G01S13/87Combinations of radar systems G01S13/872Combinations of primary radar and secondary radar G01S13/874Combination of several systems for attitude determination G01S13/876Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/878Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/88Radar or analogous systems specially adapted for specific applications G01S13/881for robotics G01S13/882for altimeters G01S13/883for missile homing, autodirectors G01S13/885for ground probing G01S13/886for alarm systems G01S13/887for detection of concealed objects G01S13/888through wall detection G01S13/89for mapping or imaging G01S13/90using synthetic aperture techniques G01S13/9005with optical processing of the SAR signals G01S13/9011with frequency domain processing of the SAR signals in azimuth G01S13/9017with time domain processing of the SAR signals in azimuth G01S13/9023combined with monopulse or interferometric techniques G01S13/9029specially adapted for moving target detection G01S13/9035Particular SAR processing techniques not provided for elsewhere G01S13/9094Theoretical aspects G01S13/91for traffic control G01S13/913for landing purposes G01S13/92for velocity measurement G01S13/93for anti-collision purposes G01S13/9303between aircraft or spacecraft in flight G01S13/9307between marine crafts; between marine crafts and fixed obstacles G01S13/931between land vehicles; between land vehicles and fixed obstacles G01S13/94for terrain-avoidance G01S13/95for meteorological use G01S13/951ground based G01S13/953mounted on aircraft G01S13/955mounted on satellite G01S13/956mounted on ship or other platform G01S13/958Theoretical aspects