Marine Radar Based on Cylindrical Array Antennas with Other Applications
First Claim
1. A method of providing and operating a radar system for detecting moving targets comprising:
- providing a cylindrical array antenna with one layer of array elements equally spaced around a cylinder;
providing a transmit/receive module for each of the array elements;
activating a subset array elements at any given time, which is typically about ⅓
rd of the total;
generating waveforms that are to be common to all active transmit/receive modules;
employing pulsed waveforms with phase or frequency modulation to provide high resolution in range;
digitally controlling the transmit/receive modules to activate a subset of the cylindrical array to transmit the waveforms generated;
controlling the amplitude and phase of the transmit signal in each of the active transmit/receive modules in the subset to form and point the respective transmit beam;
receiving returns of transmit signal in the active transmit/receive modules;
controlling amplitude and phase of the receive signal in the active transmit/receive modules to form the receive beam;
down converting the received the returns in each active transmit/receive module to an intermediate frequency;
combining the received returns from all active transmit/receive modules at an intermediate frequency in a manifold;
digitizing the down converted intermediate frequency return at the output of the manifold;
passing of digitized down converted received returns to a digital signal processor to;
obtain range resolution;
coherently process a sequence of received returns to obtain Doppler resolution, repeated in each beam for each range sample;
envelope detect the range and Doppler samples;
compare the envelope detected range and Doppler samples with at least one threshold for detection of the moving targets;
record the beam positions of detected moving targets;
compare detected moving targets with previously detected targets already in track, check for range ambiguities, and update track files;
display the tracked targets on computer monitor;
display stationary returns in a background mode;
change waveform repetition frequency on alternate scans to resolve range and Doppler ambiguities.
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Accused Products
Abstract
An all-solid-state marine radar technology based on a non-rotating cylindrical array antenna is described. Multiple transmit/receive (T/R) modules are used to form the antenna beam, which allows the beam sequencing, the dwell time in each beam position, the resolution, and the beam shape to be varied in order to make best use of the available energy. Waveforms with a high duty ratio can be used on transmit in order to make efficient use of solid-state power amplifiers. High resolution in both range and Doppler provides high measurement accuracy and superior performance in clutter. Alternate embodiments, including continuous waveform embodiments are disclosed.
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Citations
24 Claims
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1. A method of providing and operating a radar system for detecting moving targets comprising:
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providing a cylindrical array antenna with one layer of array elements equally spaced around a cylinder; providing a transmit/receive module for each of the array elements; activating a subset array elements at any given time, which is typically about ⅓
rd of the total;generating waveforms that are to be common to all active transmit/receive modules; employing pulsed waveforms with phase or frequency modulation to provide high resolution in range; digitally controlling the transmit/receive modules to activate a subset of the cylindrical array to transmit the waveforms generated; controlling the amplitude and phase of the transmit signal in each of the active transmit/receive modules in the subset to form and point the respective transmit beam; receiving returns of transmit signal in the active transmit/receive modules; controlling amplitude and phase of the receive signal in the active transmit/receive modules to form the receive beam; down converting the received the returns in each active transmit/receive module to an intermediate frequency; combining the received returns from all active transmit/receive modules at an intermediate frequency in a manifold; digitizing the down converted intermediate frequency return at the output of the manifold; passing of digitized down converted received returns to a digital signal processor to; obtain range resolution; coherently process a sequence of received returns to obtain Doppler resolution, repeated in each beam for each range sample; envelope detect the range and Doppler samples; compare the envelope detected range and Doppler samples with at least one threshold for detection of the moving targets; record the beam positions of detected moving targets; compare detected moving targets with previously detected targets already in track, check for range ambiguities, and update track files; display the tracked targets on computer monitor; display stationary returns in a background mode; change waveform repetition frequency on alternate scans to resolve range and Doppler ambiguities. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification