RU171634U1 - RIGID SURFACE OPTICAL SPECTRAL PROCESSING DEVICE - Google Patents

Abstract

The invention relates to the field of optical measurements and relates to a device for optical spectral processing of an image of a rough surface. The device includes a sequential lens mounted in the focal plane of the lens, a rotating modulator disk with a recorded reference structure, three photodetectors, a multi-channel analog-to-digital converter, and an image spectrum forming and recording unit. The reference structure on the modulator disk is a periodic straight lattice recorded on three radially arranged tracks in five sectors of the disk with different spatial frequencies and with continuously changing strokes in each sector along the radius in the range of angles ± 30 ° relative to the middle of the sector. The modulator disk is equipped with sector start marks. Each integrating photodetector corresponds to its own track on the modulator disk. The technical result is to reduce the time of registration of the spectrum. 2 ill.

Description

The invention relates to optical analog devices for spectral processing of images, for example, the surface of the sea, using incoherent light and can be used to solve a number of scientific and technical problems, in particular, to measure the spectra of images of a rough surface, including the spatial spectrum of waves of a water surface in real time.

Optical analog analyzers are known in incoherent light, for example, an optical analyzer of the spectrum of signal recordings OSA-2 (see Zverev VA, Orlov EF “Optical analyzers”, M., Soviet Radio, 1971, pp. 96-99) . This optical analyzer of the spectrum of signal recordings contains sequentially located on the optical axis of the device: a lens, a block of optical arrays with a mechanism for shifting them relative to each other, a frame for mounting the recording medium of the analyzed signals (film), an aperture and an integrating photodetector in the form of a lens system with a photomultiplier. The disadvantage of this analyzer is the need to record the image of the water surface on a carrier (film) for subsequent analysis. The use of media reduces the dynamic range of the analyzed images due to the nonlinearity of the amplitude characteristics of the media. In addition, there are additional noises introduced by the image carrier, and the ability to quickly process images and obtain spectra in real time is lost.

A further analogue of the developed device for optical spectral processing of the image of a rough surface is a device known by the copyright certificate SU No. 1018132, IPC ³ G06G 9/00, G01R 23/16, publ. 05/15/1983, which conducts spectral processing of the optical image of a rough surface, such as sea waves, simultaneously for five spatial frequencies in real time. The device comprises a sequentially placed lens for forming an image of a rough surface, a modulator fixed to the focal plane of the lens, an optical circuit and a photodetector that is electrically connected to a time frequency spectrum analyzer. The modulator is a set of spatial frequency filters and is made in the form of a set of optical gratings, periodic along the X axis and having discrete different periods along the Y axis. The optical scheme is made in the form of a lens.

A disadvantage of the distant analogue is that the device simultaneously records only five spatial frequencies of the wave spectrum of the water surface and only in one direction of the wave vector defined by the X axis, which does not allow real physical processes to occur, for example, on the surface of the ocean, since this requires real-time registration of a two-dimensional wave spectrum with a much larger number of simultaneously measured spatial frequencies of the spectrum in different wave directions.

The closest analogue to the developed device for optical spectral processing of an image of a rough surface is a device known according to the patent of the Russian Federation for invention No. 2400705 (Device for optical spectral processing of an image of a rough surface: patent for invention No. 2400705 RU: IPC G01B 11/30, G06K 9/58, G01R 23/16 / E.M. Zuykova, V.I. Titov, Yu.I. Troitskaya; Institution of the Russian Academy of Sciences Institute of Applied Physics RAS. - 2009103024/28; 01/30/2009; publ. 09/27/2010, bull. 27), which performs spectral processing of the optical image w rohovatoy surface, for example sea waves, in real time, and registers its two-dimensional spectrum. The prototype device comprises a sequentially placed lens for forming an image of a rough surface, a rotating prism for image rotation, a rotating disk modulator mounted in the focal plane of the lens, an optical circuit and a photodetector that is electrically connected to the computer. In this device, the disk modulator scans the image spectrum for spatial frequency due to the applied reference structure in the form of multi-helix with a frequency varying around the circumference of the modulator disk, and the prism scans the image spectrum in the direction of the wave vector due to image rotation when it is returned - translational rotation. The disadvantage of the prototype is the large registration time of the two-dimensional wave spectrum - about 1 s, since the "bundle" of the modulator disk and the prism does not allow to increase their speed due to mechanical limitations.

The problem the utility model aims to solve is to reduce the time it takes to register a two-dimensional spectrum of a rough surface.

The technical result is achieved by the fact that the developed device comprises a sequential lens, a rotating disk modulator with a recorded reference structure mounted on it in the focal plane of the lens, at least one integrating photodetector, and also a unit for generating and recording the image spectrum of a rough surface, the functions of which runs a computer equipped with a multi-channel analog-to-digital converter (ADC)

New in the developed device is that the reference structure on the modulator disk is a periodic straight lattice recorded on three radially arranged tracks in five sectors of the modulator disk with different spatial frequencies and with continuously changing stroke directions in each sector in a radius range of angles ± 30 ° relative to the middle of the sector, where the bars of the lattice are directed along the radius of the modulator disk, while the modulator disk is provided with marks on the beginning of the disk sectors to generate a sync lsov beginning sectors using optocouplers, and each of the three tracks on the disc modulator corresponds to integrating a photodetector.

The device is illustrated by the following drawings.

In FIG. 1 is a block diagram of a developed device for optical spectral processing of images of a rough surface: 1 — lens, 2 — disk modulator, 3 — integrating photodetector (three pieces), 4 — optocoupler, 5 — spectrum forming and recording unit.

In FIG. 2 shows a modulator disk with a reference structure applied.

The device carries out its work as follows.

First, the lens 1 creates an image of a rough surface on a modulator disk 2 mounted in the focal plane of the lens (see Fig. 1).

On the modulator disk 2 there are five sectors of three tracks with a width of 16 mm each (see Fig. 2), on which direct gratings are applied with different spatial frequencies. The first track is at an average distance from the center of 99 mm, the second is 83 mm, the third is 67 mm. We will consider the first sector to be the sector with the minimum spatial frequencies of the gratings on all three tracks: 0.1; 0.6; 2.9 strokes per millimeter, respectively. On the second: 0.15; 0.85; 3.7 strokes per millimeter, respectively. On the third: 0.2; 1,2; 4.6 strokes per millimeter, respectively. On the fourth: 0.3; 1.65; 5.6 strokes per millimeter, respectively. And on the fifth: 0.4; 2.2; 6.7 strokes per millimeter, respectively. Thus, the disk modulator 2 allows you to obtain the spectra of the image for 15 discrete spatial frequencies.

Moreover, in each sector, the direction of the direct gratings continuously varies along the radius in the angle range of ± 30 ° relative to the middle of the sector, where the strokes of the gratings are directed along the radius of the modulator disk 2. At the outer radius, where there is no recording of direct gratings, there is a track with five marks of the beginning of sectors . As a result of this recording of the gratings on the modulator disk 2, the angle analysis during rotation of the modulator disk 2 becomes continuous. The angle resolution of the spectrum is determined by the size of the integrating window (see Fig. 2).

The difference between the modulator disk 2 in the proposed utility model and the prototype modulator disk is that due to the above-described reference structure of its use, it is enough to use the proposed device to scan the image spectrum of a rough surface both in spatial frequency and in direction wave vector. This removes the mechanical restrictions on the speed of the “bundle” of the modulator disk and the prism that are present in the prototype, and the time to obtain a two-dimensional spectrum of a rough surface is determined only by the rotation speed of the modulator disk 2.

Each track of the modulator disk 2 corresponds to an integrating photodetector 3. For each integrating photodetector 3, a bold ellipse shows the integrating window on the corresponding track of the modulator disk 2. Marks of the beginning of sectors located along the outer radius of the disk of modulator 2 at the beginning of each sector (Fig. 2), are read using an optocoupler 4. The mark at the beginning of the sector with minimum spatial frequencies is smaller in size along the circumference and simultaneously serves as a sync pulse of disk rotation. Optocouple 4 is an electronic device consisting of a light emitter (usually an LED) and a photodetector (photodiode) connected by an optical channel. When the modulator disk 2 is rotated, labels representing opaque sections on the modulator disk 2 interrupt the light flux on the photodiode of the optocoupler 4, forming a pulse at the output of the optocoupler 4.

Thus, the image of a rough surface created by the lens 1 on the modulator disk 2 is modulated by direct gratings within the integration window of each integrating photodetector 3 on each track of the modulator disk 2, then the modulated image within the integration window is collected using the corresponding integrating photodetector 3 on each track . The signal from the output of each integrating photodetector 3 will be proportional to the Fourier spectrum of the image of a rough surface. Next, the signals from the output of each integrating photodetector 3 and from the optocoupler 4 are fed to a block for forming and recording a spectrum 5 of an image of a rough surface, the function of which is performed by a computer equipped with a multi-channel analog-to-digital converter (ADC), and in which a two-dimensional spectrum is formed on the basis of the obtained set of signals rough surface.

As a result, the proposed device — optical spectral image processing — can record the image spectrum of a rough surface in coordinates of the spatial frequency — direction of the wave vector in one revolution of the disk modulator 2, and the spatial spatial spectrum is discrete 15 spatial frequencies (three tracks with direct gratings with different spatial frequencies into 5 sectors of the modulator disk 2), and the spectrum along the directions is continuous in the angular range of 60. The spectrum recording time is is determined by the rotation speed of the modulator disk 2, which can be selected. For example, when the modulator disk 2 is rotated at a speed of 25 r / s, as occurs in the prototype, the registration time of one implementation of the two-dimensional spectrum by the proposed device is 25 times less than the registration time of the two-dimensional spectrum by the prototype.

The advantages of the developed device for optical spectral processing of the image of a rough surface over similar devices with television cameras are the large dynamic range and the absence of “blur” of the image due to the movement of the carrier on which the device is located, since the Fourier transform is carried out instantly. Thanks to this, the developed device can, for example, record spectra of arbitrarily short waves along the ship, as soon as the observation geometry allows.

Claims (1)

A device for optical spectral processing of an image of a rough surface, comprising a sequential lens, a rotating disk modulator with a reference structure recorded on it, mounted in the focal plane of the lens, at least one integrating photodetector, and also a unit for generating and recording an image spectrum of a rough surface, the functions of which runs a computer equipped with a multi-channel analog-to-digital converter (ADC), characterized in that the reference structure on a modulator disk is a periodic straight lattice recorded on three radially arranged tracks in five sectors of a modulator disk with different spatial frequencies and with continuously changing stroke directions in each sector in a radius range of ± 30 ° relative to the middle of the sector where the lattice strokes are directed along the radius of the modulator disk, while the modulator disk is equipped with marks of the beginning of the sectors of the disk for generating clock pulses of the beginning of the sectors using an optocoupler, and each of the three tracks on the disc e-modulator corresponds to integrating a photodetector.

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