Abstract: The invention provides a magnetron drive circuit which drives a magnetron to produce a generally rectangular-shaped narrow transmission pulse having sharply shaped rising and falling edges. The magnetron drive circuit includes a nonlinear load circuit and an active damper circuit. The nonlinear load circuit becomes on at around 80% of a peak output voltage of a pulse transformer (at which the magnetron begins to oscillate) is connected to a secondary winding of the pulse transformer in parallel with the magnetron. The active damper circuit absorbs residual energy left in the pulse transformer without any need for an absorption resistor conventionally connected between both ends of a primary winding of the pulse transformer.

Abstract: A combined defense and navigational system on a naval vessel is disclosed. The disclosed system includes a track-while-scan pulse radar which is controlled to provide either navigational information or tracking information on selected targets. Additionally, the disclosed system includes a plurality of guided missiles, each of which may be vertically launched and directed toward intercept of a selected target either by commands from the track-while-scan radar or from an active guidance system in each such missile.

Abstract: The invention provides a magnetron drive circuit which drives a magnetron to produce a generally rectangular-shaped narrow transmission pulse having sharply shaped rising and falling edges. The magnetron drive circuit includes a nonlinear load circuit and an active damper circuit. The nonlinear load circuit becomes on at around 80% of a peak output voltage of a pulse transformer (at which the magnetron begins to oscillate) is connected to a secondary winding of the pulse transformer in parallel with the magnetron. The active damper circuit absorbs residual energy left in the pulse transformer without any need for an absorption resistor conventionally connected between both ends of a primary winding of the pulse transformer.

Abstract: Process and device for reducing the spectral line noise inside an aircraft, especially a rotating-wing aircraft, in particular a helicopter. Said device (1) comprises sensors (Ca, Cb) for measuring the values of vibratory and/or acoustic parameters, controllable mechanical elements (A) forming secondary sources of noise, and a main computer (CAL) determining, on the basis of the values measured by the sensors (Ca, Cb), control commands for the mechanical elements (A), as well as at least one reference sensor (CO) for measuring a reference parameter which is correlated with the noise, and possibly an auxiliary computer (4) for calculating, on the basis of the values measured by the reference sensor (CO), a reference signal, and said main computer (CAL) determines the control commands by carrying out filtering with respect to the reference signal.

Abstract: A method and apparatus for jamming radar and other electromagnetic signals is disclosed in which the jammer includes a single port, keyed primed oscillator which is primed with the low level signal received at its antenna. In one embodiment the priming signal is gradually shifted in frequency to introduce a false doppler and is then injected into the tank circuit of the oscillator which is rapidly turned on and off (keyed) to produce a rapidly pulsed signal which tracks the frequency of the shifted priming signal. In this embodiment the oscillator keying unit is itself keyed to modulate the output signal of the oscillator to provide false bearing information. In another embodiment, the priming signal is injected directly into the tank circuit of the oscillator and the frequency of the output signal from the oscillator is varied to induce false doppler information. In both embodiments the pulsed signal from the oscillator is detected as a CW signal.

Abstract: A fluid flow device includes an actuator, an RF transmitter, a gated RF receiver, and a processor. The RF transmitter is configured and arranged to produce a plurality of pulses of RF energy spaced apart in time to form a sensor field. The gated RF receiver is configured and arranged to receive RF energy reflected by objects within the sensor field. The processor is coupled to the gated RF receiver for evaluating the reflected RF energy. The processor is also coupled to the actuator and is configured and arranged to activate the actuator in response to the reflected RF energy to control fluid flow. In addition, a new low power radar sensor operates by providing radar pulses that are non-uniformly spaced in time. In operation, a burst of pulses is initiated in the transmitter. Between each burst is a period of rest time in which the transmitter is not transmitting RF energy.

Abstract: In a method and device for the encoding/decoding of the power distribution at the outputs of a system, the distribution encoder comprises an element that receives a signal s(t) and a piece of distribution information i(t), and that superposes said piece of distribution information i(t) received on said signal s(t) received. The piece of information i(t) is used for the subsequent distribution of the total power Ps of said signal s(t) at said output or outputs {S&Ggr;} of a system &Ggr;. The distribution decoder comprises one or more inputs on which there is received an encoded signal c(t) or an encoded signal divided into several signal (cj(t))j&egr;[1,2N] comprising the useful signal s(t) and the piece of distribution information i(t). It also comprises one or more outputs connected to the outputs {S&Ggr;} of said system &Ggr; to which said signal s(t) is transmitted by distributing the total power received Ps according to said piece of distribution information i(t).

Abstract: An apparatus and method for generating an electromagnetic environment in which the free field, plane wave response of electronic systems of an electrically large (greater than several wavelengths in its longest dimension) object, or objects, under test can be measured in the electromagnetic radiating near field of the transmitter array apparatus. The apparatus comprises: (1) one or more transmitting station(s), each station home to an array of radiating elements; (2) a software operating system and computer that controls the electronic circuits of the apparatus and executes an optimizing algorithm based on a Genetic Algorithm to control the radiation of each transmitting station; and (3) mechanical and electrical circuits that enable the apparatus to conduct self calibration and adjustment as required. In operation, the apparatus is placed and distributed about an object under test.

Abstract: A time domain reflectometry measuring instrument uses a microprocessor that provides added functionality and capabilities. The circuit electronics and probe are tested and calibrated at the factory. Installation and commissioning by the user is simple. The user installs the probe. The transmitter is attached to the probe. The user connects a standard shielded twisted pair to the electronics. Power is applied and the device immediately displays levels. A few simple parameters may need to be entered such as output characteristics and the process material dielectric constant.

Abstract: A system is provided for generating multiple frequencies in a specified frequency band, with a specified step size between frequencies, in which the spectral purity of the frequencies is assured. The switching speed between frequencies is very fast, limited only by the speed of the switches used. In one embodiment, only five tones are generated as the base for the rest of the synthesis, in which the relationship of the five tones is f0+/−⅛f0 and +/−{fraction (1/16)}f0. The subject system may be utilized in air defense systems for generating the transmit channels to be able to permit a missile seeker to transmit a signal at the appropriate frequency. In one embodiment, spectral purity is achieved by providing a number of stages of up converting, expanding, and dividing down of an input signal.

Abstract: A radar exciter including a direct digital synthesis (DDS) wideband waveform generator which performs the frequency synthesis function heretofore performed by a direct analog synthesizer. This is achieved by deriving the DDS frequencies, the exciter RF frequencies, the radar synchronizer clock frequency and receiver analog/digital (A/D) converter clock frequency from a common signal source generating a master frequency. The present invention eliminates the direct analog synthesizer and relies solely on the digital generation of waveforms by a DDS wideband waveform generator which performs a discrete sampling process so as to provide coherent frequency and timing relationships.

Abstract: The invention concerns a method of synthesizing a replica used in the compression filter of pulse compression radar.The replica is calculated from the spectrum of a required impulse response.The required impulse response is preferably obtained from an analytical function, such as a sinc function or a weighted sinc function, and a template.It is preferable to use calibration signals of the instrument to calculate the replica.The invention also applies to synthetic aperture radar.

Abstract: A processing method for use in providing improved SAR imagery at high duty factors that provides for enhanced radar sensitivity. Radar signals are transmitted that embody a high duty factor ultra-high resolution SAR waveform generated using a biphase code with a predetermined high pulse compression ratio. Received radar returns comprising a SAR map are Fourier transformed and multiplied by a stored set of complex weights. The resultant Fourier transformed complex weighted SAR map is then inverse Fourier transformed to obtain compressed range bins. The inverse Fourier transformed SAR map is then processed for display.

Abstract: A power distribution system (12) is provided in radar apparatus to distribute power from a 270 VDC source (60) through an intermediate power converter (70) and very high frequency (VHF) regulator/modulator units (80). Bus conductors (71,74) interconnect the source, the intermediate power converter, and the VHF units. Capacitors (71, 76) are connected to the bus conductors on the input and output sides of the intermediate power converter. Each VHF unit supplies modulating pulses to RF amplifiers (82) of an AESA array of the radar apparatus.

Abstract: A digitally-controlled pulse shaper (DCPS) is provided which precisely controls the shape of the leading and trailing edges of a transmit pulse in a radar wind profiler, or pulsed-radar. In the case of pulse coding, where phase transitions are used to segment an otherwise longer pulse, the intra-pulse phase transitions are also shaped.

Abstract: A method and apparatus for generating a low phase noise RF signal where the output from a low phase-noise stabilized local oscillator operating at relatively high frequencies in the GHz range is combined in a power combiner with a digital data stream generated by a digital waveform generator and which is representative of one or more analog signals in a predetermined frequency spectrum of relatively lower RF frequencies in the MHz range. The combined signal is applied to a Josephson junction array whose output consists of a data stream including pulses of precise constant amplitude and which is then fed to a bandpass filter circuit having a predetermined bandpass. The filter extracts the lower frequency analog signal but now consisting of a signal having low phase-noise.

Abstract: A random number generator for generating a pseudo-random code for use with ittered pulse repetition interval radar systems has been disclosed in which the code generated by the random number generator possesses the five attributes desirable for a jittered radar PRI: a flat frequency spectrum, a nearly perfect spike for an autocorrelation function, a controllable absolute minimum and maximum interval, long sequences that do not repeat, and a reasonable average pulse rate. A method for analyzing the autocorrelation properties of the code generated by the random number generator is also disclosed. A means to generate a pulse signal with random pulse repetition jitter has been disclosed.

Abstract: An apparatus and method for improving stability in a transmitter receiving a staggered pulse train includes maintaining a constant temperature of the transmitter at the start of each pulse of the pulse train. Such maintenance may be accomplished by inserting "false", "phantom" or "synthetic" pulses into the pulse train. These pulses may be inserted between pulses, prior to a cooler pulse, or after a hotter pulse. The inserted pulses are then gated out prior to the final RF transmission.

Abstract: An apparatus and method of linear frequency modulation waveform bandwidth multiplication including a digital linear frequency modulation waveform synthesizer for generating a synthesized waveform having an upchirp component of linearly varying frequency during a first half signal duration of the synthesized waveform followed by a downchirp component having linearly varying frequency during a second half of the signal duration of the synthesized waveform. The synthesized waveform is upconverted and subsequently bandpass filtered to provide a filtered waveform to a mixer for mixing with local oscillation signals. The upchirp and downchirp components of the filtered waveform are respectively mixed by first and second local oscillation signals having respective first and second oscillation frequencies in the mixer.

Abstract: X-band signals are generated from the output of a Josephson junction array which is excited by a first RF frequency waveform digitally implemented in a data stream generated by a digital waveform generator gated by a stabilized local oscillator operating at a second frequency (X-band). The Josephson junction array outputs a digital data stream having pulses of quantum mechanically accurate uniform amplitude and picosecond pulsewidth. These pulses are fed to a bandpass filter which operates to extract a low phase-noise RF signal at X-band and consisting of the sum of the first and second frequencies and which can thereafter be used to generate transmit signals in a radar system and more particularly a cryogenic radar system.

Abstract: A radar detection system includes a transmitter and a receiver. The transmitter generates a pulse including a first subpulse generated at a first predetermined frequency and a second subpulse generated at a second predetermined frequency. At least one of the first and second subpulses include a digitally adjusted rise time and fall time, each of the rise time and fall time being separately adjustable independent of the other to provide for the relative lowering of transmission power above and below the first and second predetermined frequencies. The transmitter then transmits generated first and second subpulses at the respective first and second predetermined frequencies, as digitally adjusted in rise and fall time.

Abstract: A codeword generator produces codewords in the form of digital electronic signals which may be employed, for example, in spread spectrum communications system or RADAR systems. The generator effects a mixing ergodic transformation upon a suitable irrational number to produce a complex number sequence. The generator truncates the complex number sequence to a predetermined length, thus forming a codeword. The generator then forms other codewords within a family by permuting this first codeword. Other families of codewords may be generated by employing another mixing ergodic transform to transform the same irrational number or another suitable irrational number.

Abstract: A differential gain characteristic can be equivalently improved by providing a compensation circuit. The compensation circuit compensates a differential gain of a voltage-controlled oscillator, of which oscillating frequency is controlled by a control voltage. The compensation circuit comprises a first resistor which is connected to an input side of the voltage-controlled oscillator in series and a series circuit of a second resistor and a first diode, which is connected to the input side of the voltage-controlled oscillator in parallel, and further a first bias electric source for giving a bias voltage to the first diode in a forward direction. It becomes possible to make DG to be less than 5%, even if a modulator having a larger slope of characteristic, such as DG<50%.

Abstract: A timing generator comprises a crystal oscillator connected to provide an output reference pulse. A resistor-capacitor combination is connected to provide a variable-delay output pulse from an input connected to the crystal oscillator. A phase monitor is connected to provide duty-cycle representations of the reference and variable-delay output pulse phase. An operational amplifier drives a control voltage to the resistor-capacitor combination according to currents integrated from the phase monitor and injected into summing junctions. A digital-to-analog converter injects a control current into the summing junctions according to an input digital control code. A servo equilibrium results that provides a phase delay of the variable-delay output pulse to the output reference pulse that linearly depends on the input digital control code.

Abstract: A self-calibrating pulse compression system which is able to optimally compress a chirped waveform notwithstanding variations in the chirped spectrum due to changes in transmitter characteristics or other factors. In a most general sense, the inventive pulse compression system includes a first circuit (12, 14) for providing a first waveform, a second circuit (16, 30, 32) for sampling the first waveform at predetermined time intervals to provide a plurality of calibration samples, a third circuit (30) for storing the calibration samples; and fourth circuit (16, 28, 30) for multiplying a second waveform by the stored calibration samples. In a specific implementation, the first circuit of the self-calibrating pulse compression system includes an impatt chirp transmitter (12). The output of the transmitter (12) is fed to an antenna (18) and to a first switch (22) by a circulator (20). The switch (22) is controlled by a timing circuit (16) which may be implemented with software in a host computer.

Abstract: A switched-inverter modulator for use in driving a load that comprises master and slave high voltage power supplies for providing output pulses that directly drive the load. A synchronized pulse generator provides pulse width tinting and synchronized amplitude commands to the master power supply. The timing pulse instructs the power supplies when to initiate high voltage and for what time interval. The analog waveform instructs the master power supply as to what high voltage level to obtain. The master power supply may have multiple slaves connected in parallel for additional current capacity. A low voltage DC capacitor bank is connected in parallel with each of the power supplies to supplement energy storage. Isolation resistors are coupled between outputs of the respective high voltage power supplies and the load to minimize temporary shorts from ringing back into the power supplies.

Abstract: A signalling system in time-frequency space for detecting targets in the presence of clutter and for penetrating media, includes a transmitter antenna system, receiver and processor system. The transmitter antenna system generates and launches into a medium containing the targets an energy pulse (wave packet) having a predetermined duration and frequency characteristic, and which energy pulse matches at least one of the following: 1) the time-frequency reflection characteristics of the target(s) but not the clutter, or 2) the penetration time-frequency dielectric window of the medium, or 3) the time-frequency characteristics of the window of the receiver. Preferably, the time-frequency wave packet is the complex conjugate of the impulse response of the combined medium and target.

Abstract: A monolithic digital chirp synthesizer (DCS) chip using GaAs/AlGaAs HI.sup.2 L technology. The 6500 HBT gate DCS chip is capable of producing linear frequency modulated (chirp) waveforms or single frequency waveforms. The major components of the DCS are two pipelined accumulators, a sine ROM, a cosine ROM and two digital to analog converters.

Abstract: The present invention relates to a signal processing apparatus for use in radars, which can detect a target from a receive signal by digital processing. An A-D converter samples the receive signal by a clock signal A, and quantizes the sampled value. A clock accelerator generates a clock signal B having a frequency which is N times a frequency of the clock signal A. A signal latch holds an output from the A-D converter for an N clock period of the clock signal B. A digital low-pass filter performs low-pass filtering processing with respect to an output from the signal latch with the clock signal B as an operating clock. As a result, an output from the digital low-pass filter includes a more approximate value of the maximum value in the receive signals. Therefore, it is possible to provide improved accuracy of the target detection by a target detector.

Abstract: A bank of matched filters are employed to impose on a transmitted pulse, as well as the optimum matched filter receiver response, exact amplitude and phase modulations necessary to maximize the likelihood of accurate target identification. This is accomplished by subjecting the output of each matched filter (corresponding to a target signature) to a threshold level detector to eliminate identification outputs caused solely by noise. The outputs from the threshold device represents the target identification from each matched filter. Since each matched filter corresponds to a particular target, the highest output identification signal will indicate the presence of a corresponding target.

Abstract: A radar system (20) has a chaotic code source (22) with a chaotic code output (23), which generates a chaotic code according to a chaotic difference equation. The radar system (20) further includes a transmitter (24) with a carrier signal source (28) of a carrier signal (29), and an encoder (30) having as a first input the carrier signal (29) of the carrier signal source (28) and as a second input the chaotic code output (23) of the chaotic code source (22), and as an output a transmitted radar signal (36) having the chaotic code output (23) encoded onto the carrier signal (29). A radar system receiver (26) includes a correlator (46) having as a first input the chaotic code output (23) of the chaotic code source (22) and as a second input a received radar signal (44), and as an output an indication of the correlation of the first and second inputs. The correlation is used to determine the distance, speed, or other characteristic of an object that reflected the radar signal.

Abstract: A digital chirp generator for generating linear frequency modulated signals, comprises a plurality of frequency/phase accumulators pipelined together. Each frequency/phase accumulator includes a frequency accumulator driving phase accumulator. In the pipelined configuration the frequency accumulator and the phase accumulator of each frequency/phase accumulator are interconnected with the corresponding frequency accumulator and phase accumulator adjacent of the frequency/phase accumulator.

Abstract: Variable array thinning to achieve efficient radar pulse shaping for advanced radar waveforms such as pulse burst or monopulse doppler. At the beginning of the pulse, only a few elements, spread out over the array, are turned on. The effective amplitude can be controlled with precision because each element is either off or at saturation. High efficiency is maintained because the off-state of each element is long enough so that prime power is not consumed.

Abstract: The present invention is a system that performs code compression in stages where each stage includes two processing paths 36 and 38. The two paths allow bidirectional crossover cascade complementary code compression reducing the number processing stages to log.sub.2 N and reducing the number of processing by a factor of N/(2 log.sub.2 N) where N is the length of the code. Each path includes a delay provided by a delay unit 44 and each path arithmetically combines the data from its own path with data from the other path. The upper path 36 uses an adder 40 while the lower path uses an adder/substracter unit 42 which adds or subtracts depending on the phase of the transmitted complementary phase code. The delay provided in each stage increases in a binary progression with the delay of the last stage being N/2. A systolic processor 68 is the preferred embodiment although the invention could be implemented in a programmable digital signal processor.

Abstract: A pulse compression modified OMIR waveform s.sub.N (t) is obtained by computing the OMIR eigenfunctions .phi..sub.i, i=1, 2, . . . , .infin., for an autocorrelation function of the expected target impulse response, specifying a waveform c(t) having a desired pulse compression characteristic, and generating expansion terms ##EQU1## for various expansion indices N, until a desired waveform is obtained. The expansion coefficients c.sub.

Abstract: This radar system comprises an emitter (3, 4, 5) for the transmission of coherent non-equidistant pulses forming a periodic pattern and being distinguished from each other by a phase modulation according to different quasi-orthogonal laws, the average interval between pulses being of the order of magnitude of the minimum duration of the flashes. For reception, the system comprises a single receiver (7) and a device (8) for coherent elimination of the clutter and echoes of the target bodies, followed by N processing channels for pulse compression (9.1 to 9.N) by correlation with the particular phase modulation laws. The outputs from the processing channels are sent to a device (11) for elimination of secondary peaks due to partial ambiguities.The invention applies to radar surveillance systems for helicopter detection.

Abstract: An optimized theoretical approach to the design of a waveform for a matched illumination-reception radar system incorporates radar cross section codes along with detailed target geometry and system constrains to maximize the signal energy of a received echo. An Eigensystem is used to generate a family of solutions, one of which is chosen based upon system constraints to optimize the waveform.

Abstract: A ground (or similar)--probing radar system in which the signal radiation is interrupted for short intervals. Reception is possible during these intervals and the dead range is virtually eliminated.

Abstract: A method and apparatus exploiting the discovery that the crosscorrelation of constantly spaced rows of the matrices representing certain pulse codes sum to zero. In a ranging system, such as a radar, pulses are coded according to the rows of a such a matrix, transmitted sequentially and each return processed sequentially through a filter matched to one of the coded pulses. (A different preselected filter is used for each return.) The sequence of filters is chosen so that for returns for a given range interval, each filter is matched to the returning pulse, resulting in outputs from the filters representing auto-correlations of the returned pulses. These outputs are time delayed added coherently to form the compressed pulse, and annunciated as a target hit. Should the filters and returns be mismatched, as with ambiguous stationary clutter returns, the outputs of the filters are cross-correlations which, according to said discovery, sum to zero.

Abstract: A pulse compressing apparatus for use in a radar system receives an input signal data stream which has been received by the radar system and which corresponds to a transmitted long pulse. A weight coefficient generator generates the same number of weight coefficients as the number of input signal values in the input signal data stream. The same number of arithmetic units is provided and the weight coefficients are sequentially transferred to each arithmetic means where they are processed with the input signal values. The results of the processing from the arithmetic units are added together to produce a compressed pulse output.

Abstract: A radar device, of the almost linearly frequency-modulated type of the transmission signal during the pulse, comprises a transmit circuit including a high-frequency oscillator (29), a transmit-receive aerial (7) and a receive circuit including a pulse compression element (33). According to the invention, inside the transmit circuit, an Impatt diode (17) of a diode switch (16) produces directly at microwave frequency a synchronizing signal of the oscillator (pulses modulated in accordance with negative frequency slopes). For this purpose, a clock pulse generator (26) commands a switch (25) arranged in series on the conductor (19) of the supply current of the Impatt diode (17) which current is substantially continuous, to conduct for the duration of each pulse to be transmitted.

Abstract: A portion of a radar transmit pulse is inserted into a recirculating delay line having a one cycle delay equal to the duration of a transmit pulse. A pulse train coupled from the recirculating delay serves as a local oscillator for the radar receiver. The delay medium may be an optical fiber, a coaxial transmission line or a surface acoustic wave (SAW) device.

Abstract: A coherently interruptible frequency hopped chirp waveform generator has a ignal generating synthesizer and a chirp generator with digitally stored chirp samples in which both are phase locked to a reference clock and responsive to a timing and control circuit. The digitally stored chirp signal sample is D/A converted and mixed with a fixed frequency signal generated by the synthesizer forming translated chirp signals. The translated chirp signals are output, being controlled by a timing and control circuit so that a plurality of coherently interruptible and frequency selectable chirp sub-pulses are formed.

Abstract: A transmitting channel includes a pulse generator unit for generating frequency or phase code modulated pulses having a common centre frequency. The pulses are transformed to a transmitting frequency in the transmitting channel. An antenna, which is connected to the output of the transmitting channel, radiates the transformed frequency pulses and receives return signals. A receiver channel processes the return signals. The receiver channel includes a pulse compressor unit for compressing the return signals. Each pulse to be transmitted consists of two or more sub pulses, at least one of the sub pulses being substantially longer than at least another one of the sub pulses. Each sub pulse is coded with a different compression code. The compression code of each sub pulse having a low cross-correlation property with the compression codes of all other sub pulses, all sub pulses having the same center frequency.

Abstract: In a radar system, comprising a digital expander, two analog modulation signals are generated with two digital to analog converters and raised to an intermediate frequency range through a quadrature modulator. The amplitude and phase ripple of the output signal occurring in the quadrature modulator due to limited carrier and image frequency suppression are compensated through a multiple regulating circuit. To this end, if necessary calibration signals, of constant amplitude and different phase positions, are generated sequentially by means of the two digital to analog converters and the amplitude of their output signals measured in an amplitude detector. Setting values for the multiple regulating circuit are determined from the averaged amplitude measured values in a phase and amplitude correction unit which via setting elements set the requisite offset and phase and amplitude symmetry values until the deviations of the output signal in amplitude and phase disappear.

Abstract: The present invention includes an apparatus that prebiases a transmitted radar signal. The prebiasing of the transmit signal automatically aligns the return signals in one dimension or dimensionally transforms the return signals thereby removing the need for one of the dimensional processing operations of a conventinal two dimensional return signal interpolator. A map function generator produces small frequency (phase) changes in the transmitted signal during each pulse over the entire integration or exposure period. The map function generator produces a parabolic frequency change control signal applied during the integration period. The control signal is divided into segments where each segment controls a single transmit pulse. The control signal modifies a linear frequency modulation control signal. conventionally produced by high resolution radar systems.

Abstract: Sets of group-complementary code arrays which have the property of being ually orthogonal over a subinterval of their total cross-correlation function have been identified. These group-orthogonal arrays are generated by a multiplication operation upon a given group-complementary array using a matrix which has diagonal elements from vectors which are orthogonal. Composite code arrays are synthesized by interleaving rows from the group-orthogonal set of arrays, and applying the resulting rows of codes to bi-phase modulate pulses in bursts. The resulting composite waveform has the desirable property of temporal (zero-Doppler) sidelobe cancellation in the maximum unambiguous range interval and response cancellation over one or more multiple-time-around range intervals of an equivalent uncoded pulse sequence.