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US 9,696,419 B2Granted
Marine radar based on cylindrical array antennas with other applications
AssigneeMARK Resources, Inc.
InventorRichard L. Mitchell
Life of this patent
Estimating the term…
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.
Claims32
A method of providing and operating a radar system for detecting moving targets comprising:
- providing a cylindrical array antenna with at least one layer of array elements equally spaced around a cylinder;
- providing a transmit/receive module for each of the array elements;
- generating pulsed waveforms with phase and frequency modulation that are to be common to all active transmit/receive modules;
- digitally controlling the transmit/receive modules to activate a subset of the cylindrical array antenna to transmit the pulsed waveforms generated;
- controlling amplitude and phase of a transmit signal in each of the active transmit/receive modules in the subset of the cylindrical array antenna to form and point a respective transmit beam;
- receiving returns of the transmit signal in the active transmit/receive modules;
- controlling amplitude and phase of a receive signal in the active transmit/receive modules;
- down converting the received 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 to form a received beam;
- digitizing the down converted intermediate frequency return at the output of the manifold;
- passing the digitized down converted received returns to a digital signal processor;
- obtaining range resolution represented by a sequence of range samples;
- coherently processing a sequence of digitized radar returns to obtain Doppler resolution represented by a sequence of Doppler samples, repeated for each range sample;
- envelope detecting the samples in the range Doppler space;
- comparing the envelope detected samples with at least one threshold for detection of the moving targets;
- recording transmit/receive beam positions of detected moving targets;
- comparing detected moving targets with previously detected targets already in track, check for range ambiguities, and update track files;
- displaying the tracked targets on a computer monitor;
- displaying stationary returns in a background mode;
- repeating the process for all transmit/receive beam positions that constitutes a scan;
- and,
- changing waveform repetition frequency on alternate scans to resolve range and Doppler ambiguities.
19 more elements
A method of providing and operating a radar system for detecting moving targets comprising:
- providing a cylindrical array antenna with at least one layer of array elements equally spaced around a cylinder;
- providing a transmit/receive module for each of the array elements;
- generating pulsed waveforms with phase and frequency modulation that are to be common to all active transmit/receive modules;
- digitally controlling the transmit/receive modules to activate a subset of the cylindrical array antenna to transmit the pulsed waveforms generated;
- controlling amplitude and phase of a transmit signal in each of the active transmit/receive modules in the subset of the cylindrical array antenna to form and point a respective transmit beam;
- receiving returns of the transmit signal in the active transmit/receive modules;
- down converting the received returns in each active transmit/receive module to an intermediate frequency and separately digitizing;
- forming receive beams in a digital signal processor;
- processing the digitized received returns to obtain range resolution represented by a sequence of range samples;
- coherently processing a sequence of digitized radar returns to obtain Doppler resolution represented by a sequence of Doppler samples, repeated for each range sample;
- envelope detecting the samples in range Doppler space;
- comparing the envelope detected range and Doppler samples with at least one threshold for detection of the moving targets;
- recording transmit/receive beam positions of detected moving targets;
- comparing detected moving targets with previously detected targets already in track, checking for range ambiguities, and updating track files;
- displaying the tracked targets on a computer monitor;
- repeating the process for all transmit/receive beam positions that constitute a scan;
- and,
- changing waveform repetition frequency on alternate scans to resolve range and Doppler ambiguities.
15 more elements
Dependencies are inferred from the claim text.