RU2321029C1 - Method of determining height, direction and velocity of bottom boundary of cloudiness - Google Patents

Abstract

FIELD: meteorology.

SUBSTANCE: method comprises measuring three angular coordinates of the visible shift of a part of the bottom boundary of cloudiness with respect to the optical axes of two unmovable matrix photodetectors having a regular structure of pixels and located at a distance one from the other so that their optical axes are inclined to the vertical and horizontal lines at given angles and lie in a single vertical plane, and the angles of visualization are overlapped at a given height between them. The velocity and direction of motion of the bottom boundary of cloudiness are determined by comparing the position of the same part of the bottom boundary of the cloudiness at a current and previous time moment of measurements of the height of the bottom boundary of cloudiness carried out each known time interval.

EFFECT: enhanced precision and expanded functional capabilities.

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Description

The invention relates to meteorology, to methods for determining the physical parameters of the atmosphere, and allows to obtain information about the height, speed and direction of movement of the lower cloud cover (NGO).

A known method of measuring the height of the lower boundary of the clouds by means of a meter [1], which consists in observing a spot of light formed on the basis of a cloud with a searchlight beam directed vertically upward, the searchlight and photodetector spaced a known distance, and their optical axes are located in the same vertical plane. The disadvantages of this method are the small resource of the source of light pulses of the meter, the low accuracy of the data and the inability to measure in conditions of solar exposure and inconsistent cloudiness.

Also known are radar methods for measuring the height of the lower boundary of clouds, according to which solid state lasers are used in meters as a source of light pulses [2, 3]. The disadvantages of this method are the limited life of the solid-state laser, the high cost of manufacturing and operating the meter.

In addition, the disadvantages of the methods according to [1, 2, 3] are the large dimensions and significant power consumption of the meters, as well as the presence of an active emitter.

The closest technical solution to this invention is the prototype method, which implements the system [4], designed for passive determination of the coordinates of the radiation source (horizontal angle, elevation angle and distance) using two television CCD cameras. The cameras in the system [4] are located on one common vertical axis, around which they can rotate synchronously, and at a known distance from each other so that their optical axes are always in the same vertical plane. In this case, the distance is determined by the method of triangulation from the angles of the apparent displacement of the radiation source obtained from each of the cameras. The disadvantage of this method is the presence of mechanical vertical and horizontal rotary devices and, as a result, the low accuracy of the vertical and horizontal angles of the optical axes of the CCD cameras.

The problem to which this invention is directed is to eliminate the influence of mechanical movements of the photodetectors on the accuracy of measurements of the vertical and horizontal angles of their optical axes.

The technical result is to increase the reliability and accuracy of measurements and expand the functionality of meteorological observations.

The specified technical result in the implementation of the invention is achieved by the fact that in the known method, by means of two matrix photodetectors having a regular structure of the position of the pixels and located at a known distance from each other so that their optical axes lie in the same vertical plane and the viewing angles overlap, register simultaneously the radiation source and, according to the measured vertical and horizontal angles of the optical axes of the photodetectors and the angles of the apparent displacement of the radiation source, relate no optical axes of the photodetectors is determined by triangulation distance to it.

In contrast to the known in the proposed method, the stationary matrix photodetectors are arranged in such a way that their optical axes have known unchanged vertical and horizontal angles, and the viewing angles of the photodetectors overlap in the same vertical plane at a certain height between them, and three are used to determine the height of the lower cloud boundary angular coordinates of the apparent displacement of the lower cloud boundary relative to the optical axes of the photodetectors. The speed and direction of movement of the lower cloud cover is determined by comparing the position of the portion of the lower cloud cover at the current and previous moments of measuring the height of the lower cloud cover, made after a known period of time.

Comparison of the proposed method with the prototype made it possible to establish compliance with their condition of "novelty." When comparing the proposed method with other known technical solutions, no similar signs were revealed, which allows us to conclude that the condition "inventive step" is met.

The method is illustrated by drawings. Figure 1 shows the arrangement of optical receivers; figure 2 shows a diagram of the implementation of the method of measuring the height of the NGO; figure 3 shows a diagram of the implementation of the method of measuring the speed and direction of movement of NGOs.

Example. At a known distance L from each other, array photodetectors A and B are arranged so that their optical axes AA ′ and BB ′ are in the same vertical plane, and the viewing angles δ _A and δ _B have a spatial overlap at a certain height between them (Fig. one).

At a certain point in time t _i-1 , the three angular coordinates of the portion of the lower cloud cover C are measured: α for receiver A, β for receiver B and γ for both receivers (Fig. 2). In this case, the height H is calculated by the following formula:

Simultaneously with the calculation of the height H, the coordinates x _i-1 and y _{i-1 of} point C are determined.

At the next discrete time instant t _i , a second measurement of the height H and determination of the coordinates x _i and y _{i of} point C are made (Fig. 3). Knowing the time interval between measurements Δt = t _i -t _i-1 and the coordinate difference Δx = x _i -x _i-1 and Δy = y _i -y _i-1 , 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 φ

Thus, the proposed method allows to obtain information about the height, speed and direction of movement of the lower border of cloudiness. An advantage of the invention is that the accuracy of measuring the height of the lower cloud cover is enhanced by the use of stationary photodetectors with previously known values of the vertical and horizontal angles of their optical axes, while it becomes possible to determine the direction and speed of movement of the lower cloud cover.

Used sources

1. USSR author's certificate No. 598390, IPC G01C 3/06, G01S 9/62, for the invention "A meter for the height of the lower boundary of the clouds."

2. RF patent No. 2136016, IPC G01S 17/95, G01W 1/00, for the invention "Radar meter for measuring the height of the lower boundary of the clouds."

3. Advertising catalog of the company Vaisala, Finland, Ceilometr CL31.

4. European patent No. EP0379425, IPC G01C 3/18, G01S 11/12, for the invention of "System for determining the position of at least one target by means of triangulation".

Claims (1)

A method for determining the height, speed and direction of movement of the lower cloud cover at discrete time instants, according to which, by means of two matrix photodetectors having a regular pixel position structure and located at a known distance from each other so that their optical axes lie in one vertical plane and viewing angles overlap, simultaneously register the radiation source and the measured vertical and horizontal angles of the optical axes of the photodetectors and the angles of the apparent displacement of the source The radiation radiation relative to the optical axes of the photodetectors is determined by the method of triangulation, characterized in that the stationary matrix photodetectors are positioned so that their optical axes have known unchanged vertical and horizontal angles, and the viewing angles of the photodetectors overlap in the same vertical plane at a certain height between them , and to determine the height of the lower cloud cover, three angular coordinates of the apparent displacement of the lower cloud cover relative to the optical axes of the photodetectors, and the speed and direction of motion are determined by comparing the position of the portion of the lower cloud cover at the current and previous moments of measuring the height of the lower cloud cover, performed after a known time interval.

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