Remote sensing using Rayleigh signaling
AssigneeGreenwich Technologies Associates
InventorCarl M. Elam
Life of this patent
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Abstract
This invention features an improved technique for search and track surveillance. In this invention, distinct and random (in both space and time) signal beams are simultaneous transmitted from an array of transmitter source elements in a manner to cover all sectors about a source location. In addition, countermeasures against a system according to the invention are difficult because the signal waveforms for each beam are distinct and random, making prediction of any signal waveform for any beam very unlikely. An array of receiver sensor elements is provided to receive signals that are scattered from remote objects and may or may not be co-located with and share the elements of the source array element. The scattered signals are received and processed to yield the direction and range of the remote objects.
Claims56
An apparatus having a transmitter and a receiver for sensing remote objects, wherein the transmitter comprises J transmitter source elements, the apparatus comprising:
- a source generator configured to provide J carrier signals;
- a modulator signal generator configured to generate J statistically independent chip sequences, wherein each chip sequence comprises a plurality of chips, each chip having a random phase;
- and
- a modulator configured to independently modulate the J carrier signals with the J statistically independent chip sequences, respectively, to generate J modulated signals, wherein each modulated signal comprises a plurality of chips, each chip having a random phase.
A method for sensing remote objects comprising:
- generating J carrier signals;
- generating J statistically independent chip sequences, wherein each chip sequence comprises a plurality of chips, each chip having a random phase;
- and
- independently modulating the J carrier signals with the J statically independent chip sequences, respectively, to generate J modulated signals, wherein each modulated signal comprises a plurality of chips, each chip having a random phase.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- and
- one or more processing elements configured to perform beamforming for one or more directions of interest on the received scattered modulated signals and signal comparison.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- a storage element configured to store snapshots of the received scattered modulated signals and output the stored signals multiple times;
- and
- a processing element configured to perform, for one or more directions of interest, beamforming on the stored signals and signal comparison.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- a signal combiner configured to combine the received scattered modulated signals to form a resultant signal;
- and
- one or more processors configured to simultaneously perform beamforming for one or more directions of interest while performing signal comparison between the resultant signal and a predicted transmitted signal.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- a signal combiner configured to combine the received scattered modulated signals to form a resultant signal;
- a storage element configured to store snapshots of the resultant signal and output the stored resultant signal multiple times;
- and
- a processor configured to perform, for one or more directions of interest, beamforming while performing signal comparison between the resultant signal and a predicted transmitted signal.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- and
- one or more processing elements configured for one or more directions of interest to randomize phases of the received scattered modulated signals and to perform signal comparison.
An apparatus for receiving modulated signals to detect remote objects, wherein the modulated signals have been transmitted by a transmitter wherein each modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects, the receiver comprising:
- receiver sensor elements to receive the scattered modulated signals;
- a storage element configured to store snapshots of the received scattered modulated signals and output the stored signals multiple times;
- and
- a processing element configured to randomize phases of the received signals and to perform signal comparison for one or more directions of interest.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and each transmitted modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- performing beamforming and signal comparison on the received scattered modulated signals with one or more processors for one or more directions of interest.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and each transmitted modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- storing snapshots of the received scattered modulated signals;
- outputting the stored signals multiple times;
- and
- performing beamforming and signal comparison on the stored signals, for one or more directions of interest.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- combining the received scattered modulated signals to form a resultant signal;
- and
- performing beamforming on the resultant signal with one or more processors for one or more directions of interest, while performing signal comparison between the resultant signal and a predicted transmitted signal.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and each transmitted modulator signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- combining the received scattered signals to form a resultant signal;
- storing snapshots of the resultant signal;
- outputting the stored resultant signal multiple times;
- and
- performing, for one or more directions of interest, beamforming on the resultant signal while performing signal comparison between the resultant signal and a predicted transmitted signal.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and each transmitted modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- and
- randomizing phases of the received scattered modulated signals and performing signal comparison with one or more processors for one or more directions of interest.
A method for sensing remote objects comprising:
- receiving transmitted modulated signals, wherein the transmitted modulated signals have been transmitted by a transmitter and each transmitted modulated signal includes a plurality of chips, each chip having a random phase and wherein the modulated signals are scattered by remote objects;
- storing snapshots of the received scattered modulated signals;
- outputting the stored signals multiple times;
- and
- randomizing phases of the stored signals and performing signal comparison, for one or more directions of interest, with a processor.
Dependencies are inferred from the claim text.