SU1596315A1 - Device for optical spectrum processing of rough surface image - Google Patents

Abstract

The invention relates to analog computing techniques and can be used to measure the temporal image spectra of a rough surface, in particular a sea surface. The goal is to increase accuracy. To achieve the goal, the modulator has the ability to reciprocate in the horizontal plane and is equipped with a group of contacts, LEDs and photodiodes that facilitate the synchronous conversion and filtering of temporal frequencies corresponding to spatial frequencies on the sea surface image. 2 hp ff, 1 ill.

Description

the direction of movement of the modulator 3 is connected to the input of setting the phase variation of oscillator 14. Generator outputs 13 and 1 are connected respectively to the first and second inputs of the frequency converter frequency converter 12. N reference inputs of frequency converter 12 are connected to the outputs of the corresponding photodiodes 11. Photodetector output 5 is connected to the information input of the frequency converter 12, the N outputs of which are connected to the corresponding inputs of the analyzer 1. In addition, (Y-I) - optical flat lattice 6 of the modulator 3 is made and in the form of two combined in one plane optical gratings, installed with the possibility of changing the mutual orientation of the bands, and k optical gratings 6 (k N) oriented at different angles of the horizontal axis. Frequency converter 12 contains N synchronous detectors 15, each of which consists of a band-pass filter 1b, single-band signals 17 and 18, a multiplier 19 and a low-pass filter 20. The output of the band-pass filter 16 of each synchronous detector 15 is connected to the information input of the corresponding single-sided modulator 17, the output of which is connected to the second input of the corresponding multiplier 19. The output of the multiplier 19 of each synchronous detector 15 is connected to the input of the corresponding filter 20. The inputs of the bandpass filters 16 are combined and are the information input of the converter 12. The carrier inputs of the single-band modulators 17 and 18 are combined and are respectively the first and second inputs of the carrier frequency 12. Ono photoelectret ny input of each single-band fashion l torus 18 is a corresponding reference input of the converter 12 and the output of each filter 20 is a respective output transducer 12. The device operates as follows. Lens 2 forms an image of the investigated surface (in this case, the sea surface) in the plane of the optical lattices 6 of the modulator 3. When displaced along the X axis, the modulator 3 converts the image focused by the lens 2 into N light signals, the brightness of which is proportional to the product of the modulator density 3 and the brightness of the image of the sea surface in coordinates X, Y. In this case, the phase of each signal has a component (2.jr /;) Vt, where is the spatial period of the corresponding lattice 6j V is the displacement speed of the modulator 3. Lights The signals from the output of the modulator 3 are integrated by lens i, and the photodetector 5 converts the light signals into electrical signals to the input of the frequency converter 12. The band-pass filters 1b of the synchronous detector 15 separate the electrical signal into components corresponding to the light signals formed by optical gratings 6 moving modulator. 3. The signals at the outputs of the band-pass filters 16 have the following form:, t) (-V27 - -, xcosC -; - V, t ± -:; - Vt), where L (is the direction of the analysis along the azimuth angle; €, (/. c) is the spectral density of the slopes of the waves in a spatial period of 1 "in the direction of Lf, respectively the central frequency and bandwidth of the corresponding bandpass filter I6i is the maximum velocity of waves on the surface under study relative to the plane of the optical arrays 6. These signals are fed to the inputs of the corresponding single-band modulators 17, on the supporting inputs signal generator 13 is supplied to the carrier frequency. plank modu5

A torus 17 in each synchronous detector 15 transfers the signal from the output of the corresponding filter 16 to the frequency oJ of the generator 13. At the same time, the auxiliary reference signal generated by each photodiode 11 by the corresponding LED 10 when the corresponding optical lattice 6 of the modulator 3i is displaced between them arrives at the reference input of the corresponding single-band modulator 18. The signal with the frequency to the generator 1 is fed to the other input of each single-band modulator 18. Single-band modulators 18 carry out the transfer Aux of the auxiliary reference signal from the corresponding photodiodes 11 to the frequency uJ of the generator 1.- Signals at the outputs of single-sided modulators

18 have the following form:.

Acos (wt + - Vt).

The signals generated by single-band modulators 17 and 18 are fed to the corresponding inputs of the multiplier 19. At the output of the multiplier

19, in each synchronous detector 15, a signal is generated at the difference frequency Wo ω-Ы.

Each low-pass filter 20 filters out the signal components with a frequency greater than the cut-off frequency from "U, where" is the passband of the corresponding band-pass filter 1b. At the outputs of the filters 20, the signals are

., 21Г.

-

t

 r-j

K1

2 -

xCOsCtOjt 4- -V t).

From the OUTPUTS of the filters 20, the signals arrive at the analyzer 1 of the time frequency spectrum.

When changing the direction of the displacement of the modulator 3 with the electric motor 8 and the cam mechanism 7, the group 9 of contacts provides the formation of a signal to the input of the task of changing the phase of the generator 1.

In this case, the phase of the generator signal 1A changes to T, and the signals to

9f3156

the outputs of the single-sided modulators of the tori 18 take the form

7lf - 5 AcosCwt -4 Vt).

Pi

Consequently, in any direction of movement, the modulator 3 provides for the in-phase processing of the signals formed by the image of the sea surface.

Analyzer 1 works either in the mode of formation and recording of current

. random realizations of the time spectrum, or in the mode of incoherent temporal accumulation of random realizations of the spectrum using a multichannel integrator, which is part of analyzer 1. In the first case, at the output of analyzer 1, current spectra of the sea surface are formed, which determine the period and form of modulation of long energy-carrying waves, and also compare the nature of the signals at different spatial periods of the optical gratings and azimuthal angles gj of the modulator 3. In the second case, the output of the analog isator

30 1, an averaged spectrum is formed from which it is possible to determine the average shift of the center of the spectrum from the frequency of cos, caused by the projection of the wind drift and current on. the direction of the analysis and the phase velocity of the wave being analyzed, as well as the 1hrinu of the spectrum, due to the orbital velocities of the long modulating energy-independent waves.

Claims (1)

1. A device for optical spectral processing of an image of a rough surface, containing an analyzer of a spectrum of temporal frequencies and a lens sequentially arranged on the optical axis, a modulator placed in the adjoining plane of the lens, a lens and photo receiver, 50 and the modulator is made in the form placed in a plane, perpendicular to the optical axis, N rectangles from optical flat arrays of different periods, with their long sides, different, so that, in order to improve accuracy, N svetodibdov, N photodiodes, a frequency converter, first and second generators