SU1571794A1 - Device for determining centres of interference bands - Google Patents

Abstract

The invention relates to television. The purpose of the invention is to improve the accuracy and reliability of the determination of the centers of interference fringes (CIP). The device contains a television camera 1, ADC 2, delay lines 3, 4, and 5, comparison blocks 6-13, electrons AND 14, 15, and 16, and electr OR 17. Detection of the digital-optical control takes place in accordance with a predetermined algorithm for processing samples. This process is repeated for each element of the interferogram. At the end of the image scan, all the DICs are detected. The specified detection algorithm for the DIC provides more accurate and reliable detection of the DIC, since DIT is enabled to detect the distorted macrorelief so that the angle between the line of maximum values and the axial lines of the synthesized aperture is close to 45 °. 4 il.

Description

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The invention relates to television technology and can be used in the analysis of interferograms.

The aim of the invention is to improve the accuracy and reliability of determining the centers of interference fringes.

Fig. 1 is an electrical block diagram of the proposed device for determining interference fringes; Fig. 2-4 are examples of determining the centers of interference fringes.

The device for determining the centers of interference fringes contains a television camera 1, an analog-digital converter 2, first, second and third delay lines 3-5, first - eighth comparison blocks 6-13, first - third elements 14-16 and OR element 17

The device works as follows.

The image of the analyzed interferogram is projected onto the television camera 1. The output of TV camera 1 is converted by analog-to-digital converter 2, and the result of the conversion is sequentially recorded in the first, second and third delay lines 3-5, made, for example, in the form of a shift register. The number of cells in each shift register is equal to the number of K elements in the page.

ke television image. At the end of the third line, all three registers are filled and on their respective outputs there are signals from the image elements forming the cruciform multi-element aperture.

The detection of the center of the interference band occurs in accordance with the sample processing algorithm:

0 (X0, Y0) GM: () L (S) A L () L ();

0 (X0, Y0) M: (C “iA) L () L A ());

0 (X0, Y0) eM: () L () L L () L ().

where X-, YO are the current coordinates of the image elements j M are the set of points belonging to the fringes;

g

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five

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five

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five

D - a symbol of logical multiplication.

At the first outputs of the fifth, sixth, seventh and eighth blocks 10–13 comparisons, the signals of a logical unit are formed in the case when the signals at the first inputs of these comparison blocks are larger than the signals at their second inputs, which corresponds to the case D A (Fig. 2). In this case, the signal of the logical unit appears at the output of the second element AND 15, which causes the appearance of the signal of the logical unit at the output of the element OR 17. This corresponds to the situation of correct detection of the center of the interference band.

In the case when the conditions with "cA; shh, 1 (fig.z),

at the second outputs of the fifth, sixth, seventh, and eighth blocks 10–13 of the comparison, there appear signals of a logical unit that arrive at the input of the third element I 16. At the same time, a signal of a logical unit appears at its output, which causes signal of a logical unit at the output of the element OR 11.

In the case when the conditions О А А, (Fig. 4) are fulfilled, the signals of a logical unit appear at the outputs of the first, second, third and fourth blocks 6–9 of the comparison, which causes the appearance of the signal of the logical unit at the output of the first element 14 and at the output of the element OR 11.

This process is repeated for each element of the interferogram. At the end of the image scan, all fringes are detected.

The proposed algorithm for detecting the centers of interference fringes provides more accurate and reliable detection of the centers of interference fringes. Since the detection of the centers of interference fringes, which are twisted by macrorelief, is provided, the angle between the maximum value line and the axial lines of the synthesized aperture is close

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to 45.

Claims (1)

Invention Formula An apparatus for determining interference fringe centers, comprising serially connected television camera, whose optical input is the input of the image of interference fringes, the analog-to-digital converter, the first, second and third delay lines per K clock, as well as the first, second, third, fourth and fifth units of comparison, the first and second elements And the OR element, with the n-th output of the second delay line, where 1 Ј p «cK, is connected to the first inputs of the first, second, third and fourth comparison blocks, the n-th output of the first delay line is connected to the second input of the first comparison block, n -1st and n + 1th pins of the second delay line are connected to the second inputs of the third and second comparison units, respectively, the nth terminal of the third delay line is connected to the second input of the fourth comparison block, the output of the first and the output of the fourth comparison block are connected to the first and e with the fact that, with a chain, increasing the accuracy and reliability of determining the centers of interference fringes, the sixth, seventh and eighth comparison blocks and the third AND element, the output of which is connected to the third input of the OR element, are introduced, and the outputs of the second and third comparison blocks are connected respectively to the third and fourth inputs of the first element And, the n-th output of the first delay line is connected to the first inputs of the fifth and sixth comparison blocks, the n-th output 5 of the third delay line is connected to the first inputs of the seventh and eighth comparison units, the n-1-th output of the second delay line is connected to the second inputs of the sixth and eighth comparison blocks, the n + 1-th output of the second delay line is connected to the second inputs of the fifth and fifth the seventh comparison block, the first outputs of the sixth, seventh and eighth comparison blocks to the second inputs of the first element And, you 25 are connected respectively to the second, the stroke of the first and the output of the second And elements are connected respectively to the first and second inputs of the OR element, the first output of the fifth comparison unit is connected to the first input of the second And element, which differs 0ЈM. O / o $ M A o the third and fourth inputs of the second element And, the second outputs of the fifth, sixth, seventh and eighth comparison units are connected respectively to the first, second, third and fourth inputs of the third element I. Fig.Z 0 € M Fi.by