A time domain communications system wherein a broadband of time-spaced signals, essentially monocycle-like signals, are derived from applying stepped-in-amplitude signals to a broadband antenna, in this case, a reverse bicone antenna. When received, the thus transmitted signals are multiplied by a D.C. replica of each transmitted signal, and thereafter, they are, successively, short time and long time integrated to achieve detection.

Time domain radio transmission system

A method and apparatus for preventing the occurrence of range ambiguities and Doppler ambiguities in both a radar and sonar environment. A series of N pulses are produced, each of which contains a number of contagious subpulses. Each of the subpulses exhibit a different frequency than the remaining subpulses in that particular pulse. Furthermore, the order of appearance of the subpulses in each of the pulses is unique with respect to the remaining pulses in the series. A matched filter receiver and Doppler processor are used to provide auto correlations and cross correlations to prevent the range ambiguities and Doppler ambiguities.

Radar/sonar system concept for extended range-doppler coverage

A multi PRF doppler radar processor system for airborne target search radar preferably using five PRF's. The received signal is processed through a bank of doppler filters, and the filter number and PRF of every target indication in a single range band is memorized. When indications have been made at two different PRF's, the first and second data sets are processed. The first data set is used to determine a doppler band shift value, Δf, required to bring the center of a velocity band, A 1 , to the center of the filter band, and this same Δf is applied to the second data set, from which the corresponding velocity band, A 2 is determined. The velocity bands A 1 and A 2 are converted by use of the Chinese Ramainder Theorem to an unambiguous velocity band Au. The original frequency shift Δf is applied to the center frequency of Au to determine the unambiguous doppler frequency of the target.

Multi-PRF signal processor system

Disclosed are hair care compositions and methods for preparing such compositions which provide the benefits of cleaning, conditioning, curl retention, styling and setting properties simultaneously to hair in the application of a single product. The hair care compositions contain fatty alkyl amine salts, long chain quaternary ammonium salts and mixtures thereof of anionic styling polymers in a non-anionic surfactant system, wherein the surfactant system contains nonionic surfactants, semi-polar nonionic surfactants, amphoteric surfactants and mixtures thereof. The styling, setting and conditioning agents are present in the form of fatty alkyl amine salts or fatty quaternary ammonium salts which form anionic styling polymer particulate networks upon dilution in water. These networks are dispersed in the aqueous non-anionic surfactant system and are stabilized and thickened by optional swellable polymer thickening agents. Hair care compositions of the present invention can be made in the form of structured liquids, pearlescent/opaque isotropic liquids and/or translucent/clear isotropic liquids. The hair care compositions of the present invention, which allow for re-styling of the hair by wetting the hair with water, contain non-anionic surfactants, silicones, solvents or cationic polymeric conditioning agents. Furthermore, multiple application of these hair care compositions does not produce a noticeable build-up on the hair.

Cleaning, conditioning and styling hair care compositions

The delay between a first signal and a second signal is evaluated by deriving from the first signal substantially aperiodic events, possibly by using a zero-crossing detector on a random signal, and using these events to define respective segments of the second signal. The segments are combined, e.g. by averaging, to derive a waveform which includes a feature representing coincidences of parts of the second signal associated with the derived events. The delay is determined from the position within the waveform of this feature.

Time delay determination and determination of signal shift

A pulse Doppler radar system with variable pulse repetition frequency has a coherent integrator to which the reflected pulses are supplied in order to avoid deterioration of the indication of a moving target given over-the-horizon reception. The coherent integrator subjects the reflected pulses to a simplified vectorial addition by the use of a number of filters. A precondition for the modified coherent integration is a staggering of the pulse repetition periods such that their sums formed over successive pulse repetition periods are constant, and a phase reference for the signal amplitudes is obtained such that the phase difference is equal to zero after every second pulse repetition.

Pulse doppler radar with a variable pulse repetition frequency

A pulse doppler radar having variable repetition rates, noise pulses resulting from echos received from stationary multiple-time-around objects are removed by subjecting the reflected pulses to a coherent integration modified by means of a simplified vectorial addition of the reflected pulses, using an integration circuit consisting of a plurality of filters.The signal amplitude produced at the output of each filter is individually compared to the mean value of signals produced by all other filters, and a target indication is produced when the mean value is exceeded by the amplitude of a signal from an individual filter.

Pulse doppler radar with variable pulse repetition rate

A pulsed Doppler radar device with variable repetition frequency, having at least one range channel operatively connectable at the pulse rate of the pulse repetition frequency, a doppler filter which suppresses clutter interference in the low Doppler frequency range, and a device for the variation of the pulse repetition frequency, in which the doppler filter of each range channel comprises at least one sampling-and-holding circuit and a following high pass or band pass filter, the switching pulse rate of the sampling-and-holding circuit being changeable with changes in the pulse repetition frequency, with the same high pass or band filter being utilized for all repetition frequency variations, the cut-off frequency of the following filter, if a high pass filter or, the lower cut-off frequency of such filter, if a band pass filter being approximately equal to the upper frequency of the clutter band width whereby the latter is suppressed, and the upper cut-off frequency, if a band pass filter is employed, being above the maximum pulse repetition frequency.

Pulsed doppler radar device having at least one range channel

The invention relates to a pulse Doppler radar with a video threshold and with a PPI. When ECCM measures are used in the signal processing part of the radar receiver, only a specific selection of signals is displayed on the indicator. In order to enable the operator to overview the total position in the air, the signals selected by the ECCM are underlaid by all further signals exceeding the video threshold as an additional image with reduced brightness.

Pulse Doppler radar with a video threshold

1. A pulse-Doppler-radar device with an analysis circuit in the video position, which has devices for moving target indication and for secondary integration and with a CFAR-threshold for the implementation of ECCM-measures, characterized in that in order to produce a threshold value for the target decision in the CFAR-threshold the amplitude values of the videosignals at the input of the secondary integration circuit are transferred into an intermediate store, and that a circuit for mean value formation (MB) with a following circuit for threshold value generation (M, SPw) can be switched over at its input end, via a controlled switch (U), between the output of the intermediate store and the output of the threshold value circuit, in such manner that the changeover switch (U) connects the input of the mean value formation circuit (MB) to the intermediate store prior to the first mean value formation, and, on the occurrence of a signal at the output of the CFAR-threshold (VS), to the output of the threshold value circuit (SPw) for iterative mean value formation.

Harald Siegel

Papers

Pulse doppler radar with a variable pulse repetition frequency

Pulse doppler radar with variable pulse repetition rate

Pulsed doppler radar device having at least one range channel

Pulse Doppler radar with a video threshold

Pulse-Doppler radar with a CFAR threshold