Orthophoria synthetic aperture laser imaging radar single branch scanning and launching unit

Abstract

The invention discloses an orthophoria synthetic aperture laser imaging radar single branch scanning and launching unit, which comprises a half wavelength plate, a phase plate, a polarization beam splitter, a first 1 / 4 wave plate, a linear deflection scanner, a second 1 / 4 wave plate, a reflecting mirror and a primary mirror for a transmitter telescope. According to the orthophoria synthetic aperture laser imaging radar single branch scanning and launching unit disclosed by the invention, one branch in two separation branches is subjected to linear scanning, two branches are subjected to ranging distance diffraction, and the linear term phase modulation required for the one-dimensional distance resolution of a far-field target surface and the quadratic term phase course combined by the one-dimensional aperture can be finally realized. The orthophoria synthetic aperture laser imaging radar single branch scanning and launching unit disclosed by the invention has the advantages of simple and reliable structure, small size and vibration resistance, and the linear scanning of a target position can be realized by a single scanner.

Description

Technical field [0001] The invention relates to a direct-view synthetic aperture laser imaging radar. It is a device that uses phase plate diffraction at different distances to perform wavefront transformation and direct linear scanning. The on-track phase wavefront of the device is transformed by the phase plate and decomposed into orthogonal polarization components. The two channels are diffracted at different distances to produce different wavefront phases. The cross-orbit direction directly scans one of the two separate branches linearly, and then combines them into two coaxially polarized orthogonal scanning emission wavefronts. Finally, the main mirror of the emission optics is directly imaged to the target surface to realize the linear term phase modulation required for one-dimensional distance resolution and the quadratic phase history of one-dimensional aperture synthesis. Background technique [0002] The principle of synthetic aperture lidar is derived from the princip...

AI Technical Summary

Problems solved by technology

The main problems are: the wave surface conversion scanning device of the entire emission beam is bulky, the transmission loss is large, and the vibration of the airborne platform is greatly affected; the change of the radar operating performance needs to change the phase distribution function of the light field in the emission system, and the entire system must be changed at this time. The optical and mechanical structure of the wavefront conversion scanner has poor applicability; the optical elements passed by the two polarization orthogonal separation optical paths are different, which makes the wavefront phase of the two branches easy to cause large errors

[0005] Prior technologies [3] (Liu Liren, direct-looking synthetic aperture laser imaging radar emission beam direct wave surface conversion scanner, publication number: CN103245939A) and [4] (Liu Liren, direct-looking synthetic aperture laser imaging radar separate wave surface conversion scanning device, Publication No.: CN103344952A) described in the scanning device of the direct-looking synthetic aperture laser imaging radar, the devices passed by the two polarized orthogonally separated beams are different, which may easily cause unequal optical paths, resulting in a large wavefront phase error; and the device Many, complex structure

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