Optical instruments are replacing the Tretyakov bucket
Despite the crazy pace of technology development on the planet, there are such conservative areas of knowledge, where any innovation can appear only after decades of close comparative experiments. One of these areas is meteorology. Pros and cons of this situation on the example of a specific measuring device - a precipitation gauge - I propose to discuss under the cut.
Meteorological measurements are based on measurements of basic physical quantities - temperature, pressure, relative humidity, wind direction and speed. These are the main characteristics, of which additional (but no less important) meteorological parameters are restored using various transformations and sometimes not simple formulas.
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- average values of relative humidity;
- water vapor elasticity;
- lack of moisture;
- dew point temperature;
- intensity of temperature fluctuations and wind speed;
- vertical heat and momentum fluxes;
- characteristic scales of turbulent temperature and wind speed fluctuations
etc.
All these parameters are necessary for building maps of forecasts and maintaining trends in multi-year meteorological observations. Data collection has been going on for more than 150 years and the main principle that operates in this conservative area is not to rush to change measuring instruments.
According to the principle of correctness of metrological measurements, all measurements should be clearly regulated and carried out by one type of sensor being measured. For example, you need to measure the temperature. We measure it in a special box, at a certain height, at the same time every day, with the same thermometer. The thermometer failed - replaceable with a metrological attorney of the same brand or type. And if suddenly we want to automate the process? Put the digital sensor! More accurate and not mistaken, unlike a meteorologist at the station. It is impossible. It is necessary to ensure the convergence of data and not disrupt the trend of long-term observations. Thus, in order to replace the sensor with a new one, it is necessary to take readings from the old and at the same time from the new one, to look at the convergence of data and discontinuities in measurements, to make special comparative tests and, later, for example, five years of such experiments to prevent (prevent) the sensor to such measurements.
The most troublesome, perhaps, measurement of precipitation. Nothing better is invented here than a simple bucket designed by V. D. Tretyakov. It consists of a vessel with a receiving area of 200 cm² and a height of 40 cm, where rainfall is collected, as well as special protection (in the photo, these petals are at the top), which prevents the precipitation from blowing off by the wind. Set the gauge so that the receiving surface of the bucket was at a height of 2 meters above the ground. The measurement of precipitation in mm of a layer of water is made by a measuring glass with divisions applied on it, and the amount of solid precipitation is measured after they melt in room conditions. Here is a method. I foresee various malicious comments, but I am writing as it is. But despite the conservatism of the industry, there are bold developers and companies that are ready to offer new approaches to measurements in meteorology. They are not even afraid of the requirements of long-term comparative experiments, because the tempting idea to get at the same time to the thousands of posts of Roshydromet after passing all the tests is very promising ...
The development of the IMKES SB RAS proved to be the most successful design of a fully automated precipitation gauge. The device implements an optical principle with image processing of drops and snowflakes in a certain measuring volume.
The principle of operation is extremely simple. Drops or snowflakes fly in the center and literally cast shadows on the receiver of optical radiation from the source. Measurements are in mutually orthogonal regions, which reduces the effect of overlap. The device (RF patent № 119898) showed amazing characteristics. The limiting sensitivity in terms of the amount of precipitation measured is 2 • 10–5 mm. The device eliminated the influence of the wind shortage characteristic of the Tretyakov bucket. The meter can work offline with the release of information to a remote server. An interesting feature of the device is the ability to measure the strength of precipitation, gusts, velocity of drops and the type of precipitation. The device is able to distinguish between rain, snow and hail.
The developers of the device will use its next modification in the large-scale project of IMKES SB RAS to create a large-scale system for monitoring and forecasting the state of the atmosphere. This project has an industrial partner, Sibanalitpribor LLC, and from the state the project is supported by the Ministry of Education and Science (Agreement No. 14.607.21.0030).
What are we measuring?
Meteorological measurements are based on measurements of basic physical quantities - temperature, pressure, relative humidity, wind direction and speed. These are the main characteristics, of which additional (but no less important) meteorological parameters are restored using various transformations and sometimes not simple formulas.
')
- average values of relative humidity;
- water vapor elasticity;
- lack of moisture;
- dew point temperature;
- intensity of temperature fluctuations and wind speed;
- vertical heat and momentum fluxes;
- characteristic scales of turbulent temperature and wind speed fluctuations
etc.
All these parameters are necessary for building maps of forecasts and maintaining trends in multi-year meteorological observations. Data collection has been going on for more than 150 years and the main principle that operates in this conservative area is not to rush to change measuring instruments.
What's the problem?
According to the principle of correctness of metrological measurements, all measurements should be clearly regulated and carried out by one type of sensor being measured. For example, you need to measure the temperature. We measure it in a special box, at a certain height, at the same time every day, with the same thermometer. The thermometer failed - replaceable with a metrological attorney of the same brand or type. And if suddenly we want to automate the process? Put the digital sensor! More accurate and not mistaken, unlike a meteorologist at the station. It is impossible. It is necessary to ensure the convergence of data and not disrupt the trend of long-term observations. Thus, in order to replace the sensor with a new one, it is necessary to take readings from the old and at the same time from the new one, to look at the convergence of data and discontinuities in measurements, to make special comparative tests and, later, for example, five years of such experiments to prevent (prevent) the sensor to such measurements.
Measurement of precipitation
The most troublesome, perhaps, measurement of precipitation. Nothing better is invented here than a simple bucket designed by V. D. Tretyakov. It consists of a vessel with a receiving area of 200 cm² and a height of 40 cm, where rainfall is collected, as well as special protection (in the photo, these petals are at the top), which prevents the precipitation from blowing off by the wind. Set the gauge so that the receiving surface of the bucket was at a height of 2 meters above the ground. The measurement of precipitation in mm of a layer of water is made by a measuring glass with divisions applied on it, and the amount of solid precipitation is measured after they melt in room conditions. Here is a method. I foresee various malicious comments, but I am writing as it is. But despite the conservatism of the industry, there are bold developers and companies that are ready to offer new approaches to measurements in meteorology. They are not even afraid of the requirements of long-term comparative experiments, because the tempting idea to get at the same time to the thousands of posts of Roshydromet after passing all the tests is very promising ...Optical precipitation meter
The development of the IMKES SB RAS proved to be the most successful design of a fully automated precipitation gauge. The device implements an optical principle with image processing of drops and snowflakes in a certain measuring volume.
The principle of operation is extremely simple. Drops or snowflakes fly in the center and literally cast shadows on the receiver of optical radiation from the source. Measurements are in mutually orthogonal regions, which reduces the effect of overlap. The device (RF patent № 119898) showed amazing characteristics. The limiting sensitivity in terms of the amount of precipitation measured is 2 • 10–5 mm. The device eliminated the influence of the wind shortage characteristic of the Tretyakov bucket. The meter can work offline with the release of information to a remote server. An interesting feature of the device is the ability to measure the strength of precipitation, gusts, velocity of drops and the type of precipitation. The device is able to distinguish between rain, snow and hail.
Summary
The developers of the device will use its next modification in the large-scale project of IMKES SB RAS to create a large-scale system for monitoring and forecasting the state of the atmosphere. This project has an industrial partner, Sibanalitpribor LLC, and from the state the project is supported by the Ministry of Education and Science (Agreement No. 14.607.21.0030).
Source: https://habr.com/ru/post/239945/
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