SU1659795A1 - Photometer for scanning firmament - Google Patents

Abstract

The invention relates to the field of geophysics and allows you to quickly detect the presence of clouds, lightning flashes, and traces of falling meteorites. The purpose of the invention is to increase the scanning speed. The photometer contains several lines of optical fibers, and in each line the angle between the direction of the normals to the input ends of the optical fibers (all the normals in this line are parallel to each other) and the horizon line is the same, but the height of the scanning line in the sky is different for each fiber of the line. Due to this, the measurement of both the azimuth and the height of the object being sighted is provided. Fast scanning is provided by rotating the input optical device and alternating optical communication of each fiber array with the photodetector. 3 il. $ (L

Description

The invention relates to geophysics and can be used for optical scanning of the sky for the purpose of high-speed measurement of the brightness of various points of the entire sky, which, in particular, makes it possible to detect the presence of clouds, lightning flashes, traces of falling meteorites, etc.

Figure 1 shows one of the lines of optical fibers; Figure 2 shows another line of optical fibers (the angle between the normal to the input ends and the plane of the horizon); FIG. 3 shows the input receiving device in its entirety.

The photometer contains a base 1, a line of light guides 2, input ends of 3 light guides with depolators installed in front of them 4, output ends of 5 light guides mounted on base 1,

the light guide unit 6, the lens 7 and the radiation receiver 8.

In FIG. 3, the nodes of the input optical device are separated for clarity. The upper node consists of groups of rigid, inclined fibers with their ends at an angle to the horizon. This inclination varies from one group to another in the range of angles to the horizon from 0 to 90 °. Figure 1 shows one of these groups, the ends of which are located horizontally (0 ° to the horizon); 2 - another group - ends at an angle of 45 ° to the horizon; Fig. 3 shows several groups, in each of which the ends have their own inclination. In order not to clutter figure 3, not all the fibers of this group are shown, but only one. The position of the other fibers is symbolically depicted by circles running along the diameters of the base circle. Top knot

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consists of a flat cylindrical base 1, which is penetrated by light guides 2 that are rigidly fixed to it and passing through it, and depolarizers 4 are installed near the inlet ends 3 of each fiber. The depolarizer is necessary because light, for example, a daytime cloudless sky, is polarized . Due to the polarization of light in the fiber itself, this can lead to significant and difficult to take into account errors. With the help of a depolarizer, these errors are eliminated. The length and diameter of the tube determine the angle of the instrument solution. The output ends of the 5 optical fibers are located in the lower plane of the base. All other fiber optic lines shown in Figs. 1,2 and 3 are similar in structure. They differ only in length and inclination. The output ends of the rulers are located by centers of long straight lines — diameters of base circles (FIG. 3). The angular distance between adjacent diameters corresponding to these rulers is 360 ° / n, where n is the number of rulers. The inclination to the horizon from one group to another varies uniformly with an angular pitch of 180 ° / (p-1), which is clear from FIG. 3. The block of light guides 6 consists of a monolithic cylinder (FIG. 3) with optical fibers rigidly mounted into it. The input and output ends of these fibers lie in the plane of the bases of the cylinder; the axis of the optical fibers lie in the same plane along the diameter of the cylinder. A collecting lens 7 is located under the unit of light guides b and its focus is radiation receiver 8 (Fig. 1). The diameters of the ends of all optical fibers of the upper and lower nodes are the same. The rotation of the nodes around the vertical axis is carried out by gear wheels, driven or by other known methods.

To clarify the operation of the device, we choose a spherical coordinate system. Azimuth A will be counted from the vertical plane of the horizon. The inclination of the fibers of different groups is characterized, therefore, by different heights of H. The azimuth of the measured points A is determined by the rotation of the block of fibers 6 vertically oriented fibers.

When the block 6 is stationary in the drawing plane and the upper part of the device rotates with lines of inclined light guides, the light from the sky is successively supplied from the sky points from different heights, i.e. light successively on each group of light guides will come from points of the sky with a height of O, Hi, H2, Nz ,. ., 90 ° - the number of these points is equal to the number of lines of optical fibers. In this case, the azimuth of these points is equal to either zero or 180 °, since the block of vertical light guides was supposed to be fixed. Thus, in this case, the light comes from the points of the sky, lying at different heights above the horizon, but with two azimuths - 0 ° and 180 °. Consider the path of the rays at a given H and A. If the output ends of this group of inclined light guides are installed so that their centers are t0 s on the same vertical axis with the centers of the respective input ends of block 6 (in pairs), the light from the sky passes through depolarizer 4 and further along the light guide through the lens 7 to the receiver 8. Example of a stroke

5 beam is schematically shown in figure 2. It is obvious that the other fibers also function in the same way, and the light in this group is perceived by them all in the same coordinates H and A. As a result, the total

0 the flux from all fibers of the group will be correspondingly greater than from one. During the rotation, it is possible, therefore, to receive data from the intensity of the sky at the incoming signal to the receiver.

5 different heights from 0 to 90 ° and at azimuths A 0 ° and 180 °.

In order to measure the intensity for the same altitudes at different azimuths, it is necessary to rotate the vertical block

0 light guides on the corresponding angle. The process is similar to the previous one. As a result, data can be obtained on the intensity of different points of the sky with different azimuths and heights.

5It is also clear that the intensity should be estimated from the maximum of the signal samples, which occurs when the above condition for pairwise arrangement is fulfilled along the common axis

0 centers of the ends of the respective optical fibers,

In order to prevent direct sunlight from reaching the device, a shading screen can be installed in front of it, like

5, this is done in known antinometric instruments. The speed of rotation of the nodes is limited only by the inertia of the recording devices, recording devices and with their small inertia

0 can be quite high. The appearance in the sky of rapidly vanishing objects of increased brightness (lightning, a trace from meteorites) can be fixed with great speed.

5 The advantages of the proposed device are as follows: the possibility of high-speed scanning of many points of the sky; high sensitivity, because the streams arrive at a number of fibers in this section; high angular resolution

(small angles of solution), since the diameters of the individual fibers can be chosen of very small size; reliability of the device operation - monolithic rotating blocks of optical fibers mechanically possess high strength and, therefore, allow successful rotation of the nodes; reduction of errors associated with the polarization of sky light.

Claims (1)

A photometer for scanning the sky containing an input optical device equipped with a rotation mechanism and mounted on a base optically coupled to a radiation receiver connected to a recording device, characterized in that the input optical device is made to increase the scanning speed in the form of lines of optical fibers, in each line the fibers are rigidly mounted so that the normals to their input ends are parallel and lie in one plane, perpendicular to the base plane, the angles between the normal direction to the output ends of the optical fibers and the base plane are different for each fiber line, the output ends of the optical fibers are rigidly mounted on the base along the straight lines of the straight lines so that each straight output corresponds to the output ends of only one line of optical fibers, the input optical device additionally contains t unit of optical fibers whose optical axes are parallel; the unit of optical fibers is installed with the possibility of alternate optical communication of the output ends of each fiber line with the radiation receiver, and depolarizers are installed in front of the input ends of all optical fibers. Thebes 1 1 Fig.Z