76 results about "High range resolution" patented technology

The present invention is directed to an improved radar system that produces high range resolution while using existing narrow processing bandwidths and sampling rates to achieve a low cost radar product that is particularly useful for moving targets. The present invention uses a small number of closely spaced Linear Frequency Modulated Chirps. In one embodiment typically 2, 3, 4 chirps are used. Each frequency is sampled at a rate commensurate with the narrower bandwidth, corrected for motion (Time Aligned) and combined to produce a single wide-band chirp but achieved using the lower sample rate commensurate with the narrower transmitted waveform.

A radar classifies an unknown target illuminated with a large bandwidth pulse. The large bandwidth pulse may be algorithmically synthesized. The target reflects the large bandwidth pulse to form a return. The return is digitized into digital samples at range bin intervals. A computer extracts unknown range and amplitude pairs descriptive of the unknown target from the digital samples. Some range and amplitude pairs are located within one range bin interval. Principle scatterers are extracted from the unknown range and amplitude pairs using Modified Forward backward linear Prediction to form an unknown feature vector for the target. A plurality of pre-stored, known feature vectors containing known range and amplitude pairs are retrieved from the computer. The known range and amplitude pairs are descriptive of known targets, and are grouped in clusters having least dispersion for each of the known targets. The computer associates, for the principal scatterers, the unknown feature vector descriptive of the unknown target with each of the known feature vectors. The target is classified by using highest a posteriori conditional probability density obtained from comparing the known feature vectors with the unknown feature vector. The principal scatterers descriptive of the unknown, target are estimated using a Modified Forward Backward Linear Prediction. The Modified Forward Backward Linear Prediction also estimates range of the principal scatterers forming the unknown target. The principal scatterers are tested for decaying modes. The Modified Forward Backward Linear Prediction estimates are evaluated using Cramer Reo Bound computation for robustness.

An ultrasonic wave space monitoring anti-theft device based on distance images comprises a controller, a warning device connected with the controller, a digital signal processor connected with the controller in a data mode and a waveform generator. The waveform generator can generate narrow pulse signals and linear FM signals and is connected with an ultrasonic wave emitting device. The digital signal processor is connected with an ultrasonic wave receiving device. The ultrasonic wave receiving device separates received ultrasonic wave signals into narrow pulse and linear FM signals which are transmitted to the digital signal processor respectively. The invention further discloses an ultrasonic wave space sampling method and a monitoring anti-theft method based on distance images. By forgetting weighted processing and changing position comparison processing, the misinformation probability is lowered, the problem that the ultrasonic wave high range resolution and the long detection range cannot be achieved at the same time is solved, the ultrasonic wave emitting device and the ultrasonic wave receiving device can be placed on one side of a space, and high application flexibility is achieved.

The invention relates to a radar apparatus and a method. A radar apparatus for obtaining a higher range resolution than conventional radar apparatus without increasing the bandwidth comprises a transmitter antenna (11) that transmits a frequency modulated transmit signal having a transmit bandwidth and a receiver antenna (12) that receives a receive signal reflected from said scene in response to the transmission of said transmit signal. A mixer (13) mixes said receive signal with said transmit signal to obtain a mixed receive signal, a sampling unit (14) samples said mixed receive signal to obtain receive signal samples from a period of said receive signal, and a processor (15) processes said receive signal samples by defining a measurement matrix and determines the positions of one or more targets of the scene by applying compressive sensing using said measurement matrix and said receive signal samples.

A system, method and computer program product for performing automatic navigation of a first aircraft to a second aircraft is provided. The system includes a radar system, a processor, memory, and a flight control system. The radar system generates a one-dimensional radar profile of the second aircraft. The processor determines flight information of the second aircraft based on the generated one-dimensional radar profile and one-dimensional radar profiles stored in the memory. The flight control system automatically directs the first aircraft based on the determined flight information of the second aircraft. In one embodiment, the first aircraft is an unmanned airborne vehicle and the second aircraft is a tanker aircraft. In another embodiment, the radar system may include a high-range resolution radar.

A radar apparatus for obtaining a higher range resolution than conventional radar apparatus without increasing the bandwidth comprises a transmitter antenna that transmits a frequency modulated transmit signal having a transmit bandwidth and a receiver antenna that receives a receive signal reflected from said scene in response to the transmission of said transmit signal. A mixer mixes said receive signal with said transmit signal to obtain a mixed receive signal, a sampling unit samples said mixed receive signal to obtain receive signal samples from a period of said receive signal, and a processor processes said receive signal samples by defining a measurement matrix and determines the positions of one or more targets of the scene by applying compressive sensing using said measurement matrix and said receive signal samples.

The present invention is directed to an improved radar system that produces high range resolution while using existing narrow processing bandwidths and sampling rates to achieve a low cost radar product that is particularly useful for moving targets. The present invention uses a small number of closely spaced Linear Frequency Modulated Chirps. In one embodiment typically 2, 3, 4 chirps are used. Each frequency is sampled at a rate commensurate with the narrower bandwidth, corrected for motion, Time Aligned and combined to produce a single wide-band chirp but achieved using the lower sample rate commensurate with the narrower transmitted waveform.

The invention provides a non-blind area high-range resolution laser radar wind measurement system. A laser is connected to an electro-optical phase modulator and an acousto-optic frequency shifter through a first coupler; the electro-optic phase modulator, the fiber amplifier, the circulator and the telescope are sequentially connected. The telescope is connected to a second coupler through a circulator; the acousto-optic frequency shifter, the second coupler, a balance detector, an amplifier, a dual-channel AD collection card and a computer are sequentially connected; a sinusoidal signal generator is connected to the acousto-optic frequency shifter; an arbitrary waveform generator is connected to the dual-channel AD collection card and an electro-optical phase modulator; and an external trigger is connected to the arbitrary waveform generator and a dual-channel AD collection card. The invention also provides a non-blind area high-range resolution laser radar wind measurement method. Through combination of the pseudo-random code phase modulation technology and the heterodyne detection technology, the system works under the wide pulse width and the low peak power to obtain the profile wind speed information at the non-blind area with a high-range resolution through adoption of the algorithm of removing an end face signal influence.