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DOE OSTI2024

Notes on Amplitude versus Phase Comparison Monopulse Antennas for Radar

Monopulse is a technique for determining the Direction of Arrival (DOA) of a radar echo by comparing the simultaneous signal responses from two or more antenna beams or apertures. Two principal architectures are employed: 1) amplitude-comparison monopulse, and 2) phase-comparison monopulse. For a constrained-size fully and uniformly illuminated aperture, there is no meaningful difference between the DOA angle precision achievable by an amplitude monopulse architecture versus a phase monopulse architecture. DOA angle estimation precision is almost exclusively a function of antenna size, operating wavelength, and SNR, regardless of amplitude versus phase monopulse architectures.

47 OTHER INSTRUMENTATION↗

DOE OSTI2020

Two-Channel Monopulse Antenna Null Steering

Traditional dual-channel phase-monopulse and amplitude-monopulse antenna systems might electrically steer their difference-channel nulls by suitably adjusting characteristics of their constituent beams or lobes. A phase-monopulse systems' null might be steered by applying suitable relative phase shifts. An amplitude-monopulse systems' null might be steered by applying a suitable relative beam amplitude scaling. The steering of the null might be employed by a continuously mechanically-scanning antenna to stabilize the null direction over a series of radar pulses.

42 ENGINEERING↗

DOE OSTI2024

Notes on Real-Beam Ground Mapping with Monopulse Radar

The spatial awareness required of modern flight systems is facilitated by images generated by ground-mapping radar. In the forward and aft directions, synthetic aperture techniques are not viable, leaving us with enhancing real aperture radar data. Enhancing real aperture radar data with monopulse information can be achieved with any of several monopulse beam sharpening techniques. Two such algorithms are discussed.

47 OTHER INSTRUMENTATION↗

DOE OSTI2023

Curvilinear Aperture Monopulse

By a symmetry argument, a synthetic aperture radar collection along a linear path does not collect three-dimensional information about the scene. However, it is known that vertical curvature can be used to derive some vertical position information. This paper approaches the problem from a monopulse perspective, resulting in a non-iterative computation that commutes with efficient image formation algorithms.

Story, Mark↗

DOE OSTI2026

Practical Three-Dimensional Curvilinear Aperture Monopulse Synthetic Aperture Radar

When collected over a curved path, Synthetic Aperture Radar (SAR) contains information about the three-dimensional content of a scene that can aid interpretation of this difficult imaging modality. In a point scatterer simulation with amplitudes and heights derived from a real SAR image pair, we supplement confocal processing with a monopulse-based algorithm to compute heights of certain bright points, which we find automatically. In SAR, bright points often reflect man-made infrastructure central to scene interpretation.

Story, Mark [ORNL] (ORCID:0000000289148911)↗

DOE OSTI2025

Notes on Bayliss Taper for Monopulse Radar

A radar system’s antenna characteristics are fundamental to its performance. A principal defining feature of an antenna’s performance are its often problematic sidelobes. Often in monopulse antenna topologies, the emphasis has been on the sum channel sidelobes at the expense of difference channel sidelobes. Edward Bayliss published a paper detailing a design procedure for managing the difference channel sidelobes. The resulting aperture taper now is identified by his name. This report analyzes his taper derivation, and resulting performance attributes, after which some implementation comments are rendered.

42 ENGINEERING↗