摘要:
An radar apparatus including a first transmitter, a second transmitter, a first receiver, a second receiver, and a control device. The control device is programmed to use both the characteristics of a first transmit signal from the first transmitter and a second transmit signal from the second transmitter to determine a first control signal for applying to the first receiver to determine its impulse response characteristics, and to determine a second control signal for applying to the second receiver to determine its impulse response characteristics which differ from the first receiver. These control signals have the ability to separate out the first transmit signal and the second transmit signal from their combined sum that appears at the input of the receiver. The procedure can be generalized to include any number of transmit signals and a corresponding number of control signals to separate out the transmit signals from their combined form.
摘要:
A new method for transmitter-receiver design that enhances the desired signal output from the receiver by whitening the total interference and noise input to the receiver and maximizing the output Signal to Interference plus Noise power Ratio (SINR) is presented. As a result of the whitening process, the receiver “sees” a desired signal in white noise, and the receiver structure is then optimized to maximize the receiver output at the desired decision making instant. Furthermore the new design scheme proposed here can be used for transmit signal energy and bandwidth tradeoff. As a result, transmit signal energy can be used to tradeoff for “premium” signal bandwidth without sacrificing the system performance level in terms of the output Signal to Interference plus Noise power Ratio (SINR).
摘要:
A new method for transmitter-receiver design that enhances the desired signal output from the receiver while minimizing the total interference and noise output from the receiver at the desired decision making instant is presented. Further the new design scheme proposed here can be used for transmit signal energy and bandwidth tradeoff. As a result, transmit signal energy can be used to tradeoff for the “premium” signal bandwidth without sacrificing the system performance level in terms of the output Signal to Interference plus Noise power Ratio (SINR). The two designs—the one before and the one after the tradeoff—will result in two different transmitter-receiver pairs that have the same performance level. In many applications such as in telecommunications, since the available bandwidth is at premium, such a tradeoff will result in releasing otherwise unavailable bandwidth at the expense of additional signal energy. The bandwidth so released can be used for other applications or to add additional telecommunication capacity to the system.
摘要:
The objective of this patent is to develop new signal processing algorithms for a wide-band circular electronically scanned array (CESA) or a wideband linear electronically scanned array (LESA) for use in surveillance and communications applications, where a sequence of pulses are transmitted and their returns are collected by the array for further processing. Instead of partitioning the entire wideband frequency into various subbands and then processing them separately using narrowband schemes, a frequency focusing method is proposed here to compensate and focus the wideband spatio-temporal data into a single narrow frequency band. This is made possible by operating with a pre-computed frequency focusing matrix that transforms the data from various frequency slots that are spread across the entire wideband region into a common narrowband frequency for the array outputs. Finally the focused narrowband data can be processed using conventional space-time adaptive processing methods to suppress the clutter/noise returns and detect any targets present.
摘要:
Methods are provided for obtaining wideband waveforms from a set of narrowband waveforms. The synthesized wideband waveforms are suitable for generating fine range resolution synthetic aperture radar images. Furthermore, narrowband pulse compressed data can be siphoned from the processing chain to be used in multi-look GMTI processing either independently or jointly.
摘要:
Methods are provided for obtaining wideband waveforms from a set of narrowband waveforms. The synthesized wideband waveforms are suitable for generating fine range resolution synthetic aperture radar images. Furthermore, narrowband pulse compressed data can be siphoned from the processing chain to be used in multi-look GMTI processing either independently or jointly.
摘要:
An iterative method for modifying an initial time signal to form a created signal having a prescribed envelope, and frequency notches at prescribed frequency values, wherein the created signal closely resembles the initial time signal, the envelope of the created time signal is the prescribed envelope, and the Fourier magnitude of the created time signal at the prescribed frequency values is nearly zero. The created time signal may be a real-valued signal as well as a complex-valued time signal which closely resembles an arbitrary initial time signal, including initial time signals which are standard transmit signals for radar systems, and which have Fourier transform magnitudes with notches and stop-bands at prescribed frequency values. These notches and stop bands are created by enforcing nulls of prescribed order at the prescribed frequency values within the modified time signal.
摘要:
The present invention discloses one or more methods to perform multimode processing using a single set of measured data in a multi-sensor fusion framework. In this context, various data processing methodologies are combined in parallel in a suitable manner to simultaneously image, detect, identify and track moving targets over clutter such as stationary background using data obtained from a single set of measurements. Traditionally multiple sets of data would be required to perform these tasks, furthermore the disparate datum would be processed independently of one another. By using a common data source and interconnected processors the information content of the measured data can be fully exploited and leveraged to provide actionable intelligence and aid logistics.
摘要:
A method, system, and apparatus to detect when one or more moving vehicles are close to a first vehicle, and to take necessary actions to maintain a minimum distance between vehicles in a dynamic environment by automatic navigation. A computer method and apparatus for automobile accident reduction by maintaining a minimum distance with respect to all nearby vehicles on the road. In addition, methods to synchronously move a group of vehicles on a highway through a swarming action where each vehicle keeps a region immediately around it free of other vehicles while maintaining the speed of the vehicle immediately in front or nearby is also disclosed.
摘要:
One or more embodiments of the present invention relates to the design an adaptive transmit non-periodic ON-OFF pulse width modulated (PWM) signal sequence over a radar dwell time that is matched to the target and clutter characteristics so as to maximize the target response adaptively. In this context, in the first step, some optimality criterion such as maximizing the ratio of the target output signal power to the mean clutter power at the receiver input is used to design a pre-transmit waveform. In the second step, a Pulse Width Modulation method is used to convert the pre-transmit waveform so designed to a non-periodic ON-OFF pulse width modulated (PWM) waveform signal without destroying the target and clutter matching characteristics of the pre-transmit signal. This allows maximum response from the target and minimum response from the clutter and the environment when the target and its surroundings are interrogated with the non-periodic ON-OFF pulse width modulated (PWM) signal waveform.