RU2414728C2 - Method of determining direction and speed of cloud base - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: method uses a wide-panorama automated scanning system to scan in the intrinsic emission range of the cloud field and a set of frames is recorded, which is a set of matrices, where there are N values on the horizontal and M values on the vertical, and each of the N*M values is a specific region - an image in the infrared region on the celestial sphere. The form of the matrix is changed in order to switch from angular coordinates to Cartesian coordinates. Paired comparison of all neighbouring frames is performed and the shift direction is determined for each pair, for which the most probable shift between frames is determined. The shift for the entire set of frames is calculated and a broken line is plotted, averaging of which yields the motion vector of the cloud base, from which the direction and speed of the cloud base are determined.

EFFECT: automation and high accuracy of determining direction and speed of a cloud base on real time and broader functionalities of meteorological observations.

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Description

The invention relates to meteorology, to methods for determining the physical parameters of the atmosphere, and allows you to determine the direction and speed of movement of the lower border of cloudiness (NGO).

A known method of measuring the height, speed and direction of movement of the lower boundary of the clouds using a meter [2], which consists in measuring the angular coordinates of the selected portion of the lower boundary of the cloud relative to two stationary matrix photodetectors having a regular structure of the position of the pixels, and located so that their optical axes have known vertical and horizontal angles lie in the same plane, and the viewing angles overlap at a certain height between them. The disadvantages of this method are the problem of selecting and identifying the same cloud fragment, which is performed manually by the operator, the increased sensitivity of the system to errors in photodetectors, the relatively high cost of manufacturing and operating the meter, a small viewing area and, as a consequence, the complexity and high error in determining the direction and the speed of movement in the presence of a distributed cloud field exceeding the field of view of the device when the identification of the selected area It clouds the border is impossible, that is, such a system can only work at high contrasts (cloud-lumen) radiation "broken cloud types": the cumulus, stratocumulus, Towering cumulus. The method cannot be used with vortex structures of cloud forms.

The problem to which this invention is directed, is the automation of the scanning process and analysis of the cloud field.

The technical result is automation, improving the accuracy of determining the direction and speed of movement of the lower cloud boundary both day and night in real time by shifting its spatial structure of its own radiation and expanding the functionality of meteorological observations.

Comparison of the proposed method with the prototype made it possible to establish compliance with its condition of "novelty." When comparing the proposed method with other well-known technical solutions did not reveal similar signs, which allows us to conclude that the condition "inventive step".

The method is illustrated by drawings. Figure 1 shows an example of displaying an image frame by the intrinsic cloudiness (dark color) in projection onto a plane; figure 2 shows the image of the converted frame at the selected time and through the interval Δt.

The specified technical result during the implementation of the invention is achieved by means of a wide-panoramic automated scanning system [1], which performs continuous circular scanning in the range of the natural radiation of the cloud field by almucantarat during the time at which the spatial structure of the radiation of the cloud field remains unchanged. During this time, a series of values of the energy brightness, or the radiation temperature of the cloud field through each degree, or minutes of the arc are recorded, that is, the height of the NGO is determined, which is unambiguously associated with the radiation temperature. After the data recording is completed, the angle of inclination of the scanning mirror changes, the cycle repeats, the next line is recorded. After a specified number of lines, the scanning mirror of the wide-panoramic automated scanning system returns to its original starting position, the cycle repeats, and the next frame is recorded.

Thus, a set of matrices is recorded, where horizontally - N values, and vertically - M. Each of N * M values represents a specific area - an image in the infrared region on the celestial sphere. Estimating the height of the NGO by the value of the energy brightness of the radiation temperature, the projection of the intrinsic radiation of clouds on the plane is constructed (Fig. 1). Then carried out

the shape of the matrix for the transition from angular coordinates to Cartesian coordinates (figure 2). Since the image of the projection of the cloud field is built regardless of its real height, the linear scale of an individual cell depends on the specific height of the NGO and is determined by the formula

,

,

where N _ngo is the height of the NGO (in meters), H _pxl is the conditional height of the NGO (in pixels) to construct the image of the projection of the NGO, A is the selected cell size (in pixels).

To determine the motion vector of a series of frames, a pairwise comparison of all neighboring frames is performed, and for each pair the direction of the shift is determined. To determine the shift between the matrices M ₁ and M ₂ (Fig. 2), a series of values of the measure of difference between the matrix M ₁ and the displaced matrix M _{2 is} calculated. As a measure of difference, the total value of the cell radiation differences is used.

The minimum value of the measure of difference corresponds to a pair of values (Δх, Δу) - the most probable offset of the second frame relative to the first.

By calculating the displacements for the entire set of frames, it is possible to construct a broken line, averaging which will give the motion vector of the NGO, over a selected time interval. The coordinates of the vector (x, y) show that in the selected time interval, the NGO shifted from the initial position by x cells along the abscissa axis and from cells along the ordinate axis. Go to the metric coordinates based on the linear size of the cell. Knowing the time interval Δt during which measurements were made and the coordinates of the vector (x, y), the components of the velocity V _x and V _{y are} determined, and then the velocity V

and the direction of movement of the NGO (angle φ)

The accuracy of calculating the speed and direction of movement is achieved by summing and averaging the set of individual vectors at small intervals in real time.

Information sources

1. Patent of the Russian Federation No. 2331853, IPC G01J 3/06, the invention of "Cloud Pattern Recognition Device".

2. RF patent №2321029, IPC G01W 1/00, the invention "a Method for determining the height, direction and speed of movement of the lower cloud cover".

Claims (1)

A method for determining the direction and speed of movement of the lower cloud cover in a predetermined time interval, in which, by means of a wide-panoramic automated scanning system, a cloud is scanned in the range of the natural radiation of the cloud field, a set of frames is recorded, which are a set of matrices, where there are N values horizontally and vertically M, and each of the N · M values represents a specific area - an image in the infrared region on the celestial sphere, then the shape of the mat is changed To change from angular coordinates to Cartesian coordinates, they make a pairwise comparison of all neighboring frames and determine the direction of shift for each pair, for which, using the minimum value of the measure, the differences between the corresponding matrices determine the most probable shift between frames, calculate the shifts for the entire set of frames, and build a polyline a line, averaging of which gives the motion vector of the lower cloud cover in a given time interval, along which the directions and speeds of the lower cloud cover are determined at a predetermined time interval.

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