Monopulse radar system for determining the height of a target
AssigneeLockheed Martin Corporation
InventorsPeter H. Stockman, Miroslaw T. Hepel
Life of this patent
Estimating the term…
Abstract
An improved method of estimating target elevation angle for dual squinted beam radar systems is disclosed. The target's elevation angle is estimated by receiving complex I/Q data from two receive radar beams and calculating the complex ratio of the complex I/Q data. The calculated complex ratio is compared to a set of previously determined reference complex ratios in complex lookup tables that have been corelated to known target elevation angles.
Claims20
A method of determining a detected target's elevation in a radar system, the method comprising:
- generating a main receive beam from a main receive channel and an auxiliary receive beam from an auxiliary receive channel;
- receiving complex data, I/Qmain and I/Qaux, from the main receive beam and the auxiliary receive beam, respectively;
- detecting the target based on the received data;
- calculating a received complex-ratio by computing:
- recieved complex - ratio = I / Q aux I / Q main ;
- calculating a compensated received complex-ratio by compensating the received complex-ratio for any channel-to-channel drift in the receive channels;
- and
- converting the compensated received complex-ratio to the target elevation angle.
A radar system for determining the height of a detected target comprising:
- a transmitter for generating a pulse of radio energy;
- an antenna for emitting the pulse from the transmitter and receiving a target echo signal;
- two receive channels, electrically connected to the antenna, for receiving a main monopulse receive beam and an auxiliary monopulse receive beam, measuring I/Q data from each of the two monopulse receive beams;
- a complex divider for calculating a compensated received complex-ratio of the two I/Q data;
- and
- a conversion unit for converting the compensated received complex-ratio to the target's height.
A radar system for determining the height of a detected target comprising:
- a transmitter for generating a pulse of radio energy;
- an antenna for emitting the pulse from the transmitter and receiving a target echo signal;
- two receive channels, electrically connected to the antenna, for receiving a main monopulse receive beam and an auxiliary monopulse receive beam, receiving I/Q data, I/Qmain and I/Qaux, from each of the two monopulse receive beams, respectively;
- a complex divider for calculating a compensated received complex-ratio of the two I/Q data;
- a conversion unit for converting the compensated received complex-ratio to the target's height;
- and
- a calibration circuit for executing a calibration sequence for generating a compensation factor for compensating channel-to-channel amplitude and/or phase drift with time and variation over frequency.
Dependencies are inferred from the claim text.