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Selectable range lobes using wide-band arraySelectable range lobes using wide-band array description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060273948, Selectable range lobes using wide-band array. Brief Patent Description - Full Patent Description - Patent Application Claims
TECHNICAL FIELD [0001] The present invention relates to a method and system for unambiguous range resolution of a radar system. BACKGROUND [0002] In radar systems there is a desire to keep peak power as low as possible to minimize the risk of detection. [0003] Typical solutions of today utilize fully range coded long pulses, for instance using a binary phase code. Signal classification is difficult with present solutions and different hardware solutions have to be used for a respective function category, for instance, a radar function or a jamming function. [0004] Therefore there is a demand for large duty cycle (low peak power) good range estimation for wide-band system not necessarily being pulse coded with non-deterministic transmit signals. SUMMARY OF THE INVENTION [0005] A method and a system for controlling range resolution of a radar system in a bistatic or monostatic configuration utilize an ultra-wide-band signal, which in a typical embodiment may be continuous bandwidth limited white or colored noise. The noise signal is generated and radiated for instance by an omnidirectional transmitting antenna covering the entire reception range of a receiving antenna and an echo signal is received by the receiving antenna. By means of a selected auto-correlation function defining the wide-band noise signal power spectrum, the convolution of the radiated output signal and the received echo input signal the target range information is obtained. [0006] A system according to the present invention is set forth by the independent claim 1, and further embodiments of the invention are set forth by the dependent claims 2 to 9. [0007] Further a method according to the present invention is set forth by the independent claim 10, and further embodiments are defined by the dependent claims 11 to 18. SHORT DESCRIPTION OF THE DRAWINGS [0008] The invention, together with further objects and advantages thereof, may best be understood by referring to the following detailed description taken together with the accompanying drawings, in which: [0009] FIG. 1 illustrates an illustrative array antenna for use according to the present inventive concept; [0010] FIG. 2 illustrates a principal embodiment of a wide-band array used in line with the present inventive idea and having the number of receiving antenna elements n=32; [0011] FIG. 3 illustrates in a number of graphs a) to f) the auto-correlation function for Gaussian noise with bandwidth from 200% and down to 6.25% expressed as percent of center frequency; [0012] FIG. 4 illustrates in a number of graphs a) to f) the auto-correlation function for white bandwidth limited noise using a bandwidth from 200% and down to 6.25% expressed as percent of center frequency; and [0013] FIG. 5 illustrates in a graph the convolution of radiated and received signal as a function of signal-to-noise ratio. DETAILED DESCRIPTION [0014] In a typical illustrative embodiment a very broad-banded signal is generated. The generated signal may be continuous band-limited white or colored noise and transmitted by an antenna, which for instance is isotropic in its horizontal plane. Echo signals in a bistatic or monostatic configuration are received. [0015] Each antenna may be a vertical array to increase the gain in the horizontal plane. To minimize leakage between the transmitting antenna and the receiver antennas the transmitting antenna preferably is positioned as far as possible from the receiving antennas and for instance at a different height. [0016] FIG. 1 illustrates a principal shape with n=3, the transmitting antenna is denoted as 1 and the receiver antennas are denoted 3. A structure carrying the transmitter antenna is denoted as reference number 5. A transmitter and n receivers with accompanying signal processing is housed in the electronic unit 7. FIG. 2 illustrates a practical embodiment of a circular array with n=32, the transmitting antenna sitting elevated in the middle and the receiving antenna in a ring below. One transmitter, n receivers with accompanying signal processing being housed in the base of the array. [0017] The range to the target is determined by finding the peaks in the convolution between the input and output signal. Basic Theory [0018] Suppose that the radar station is not moving and transmits the ergodic waveform s(t) having a zero average value. For a non-moving target having an extension L and a target area profile .rho.(.tau.) the received signal r(t) may be written according to: r .function. ( t ) = .intg. 2 ( R - L / 2 ) c 0 2 ( R + L / 2 ) c 0 .times. .rho. .function. ( .zeta. ) s .function. ( t - .zeta. ) .times. d .zeta. + n .function. ( t ) ( 1 ) where R is the target range, .zeta. the time integration variable and c.sub.0 the velocity of light. n(t) represents additive noise and possible disturbances. Continue reading about Selectable range lobes using wide-band array... Full patent description for Selectable range lobes using wide-band array Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Selectable range lobes using wide-band array patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Selectable range lobes using wide-band array or other areas of interest. ### Previous Patent Application: Transmit-receive fm-cw radar apparatus Next Patent Application: Energy storage in a radar level gauge Industry Class: Communications: directive radio wave systems and devices (e.g., radar, radio navigation) ### FreshPatents.com Support Thank you for viewing the Selectable range lobes using wide-band array patent info. IP-related news and info Results in 0.10051 seconds Other interesting Feshpatents.com categories: Novartis , Pfizer , Philips , Polaroid , Procter & Gamble , 174 |
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