Method and device for detecting rainfall by laser

Abstract

The invention discloses a method and device for detecting rain fall through laser. The device comprises a laser light source meeting a certain wavelength and power requirement, a parallel sheet light beam generating system based on a specified generation method, a two-dimensional water particle bidirectional sampling measurement area formed by two parallel sheets perpendicularly intersected in the horizontal direction, a linear array sensor and a rain fall detecting data processing and information feedback system. The device for detecting the rain fall through laser greatly improves the constant and stable property of detecting light and reduces measurement errors caused by light source power fluctuation. A real time humidity / meteorological parameter sensing critical starting method is adopted. Due to the fact that calibration and correction are conducted before detection, the measurement errors caused by drifting of work points of the system can be reduced to the largest extent, and meanwhile energy consumption of a measurement system is reduced. By means of the device for detecting the rain fall through the laser, the rain fall, raininess and a raindrop spectrum can be accurately and continuously observed and measured in real time. The device for detecting the rain fall through the laser can be applied to the related fields for observing, measuring and forecasting the rain fall including weather, hydrology, high way conditions, airport taking-off and landing and the like.

Description

technical field [0001] The invention relates to a method and device for detecting rainfall and raindrop spectrum in the technical field of meteorological observation, in particular to a method and device for detecting rainfall by laser with improved detection accuracy from the aspect of optical detection. Background technique [0002] With the development of society and economy, real-time observation of precipitation plays an increasingly important role in meteorology, highways, airports, hydrology and other fields. In the field of meteorology, the weather situation is analyzed according to the observation of precipitation and the climate characteristics of various places are counted; the transportation departments such as airports and expressways formulate various emergency measures according to the precipitation situation; The observation of precipitation has become an important part of people's daily life. [0003] The existing rain gauges are mainly divided into two cat...

AI Technical Summary

Problems solved by technology

After long-term development of mechanical rain gauge, although its system and technology are relatively perfect, due to the limitation of its mechanical principle, it has some difficult problems

For example, when using a tipping bucket rain gauge to observe precipitation, there are mainly the following problems: First, the field application environment is relatively harsh. Due to the settlement of sand and dust, the accumulation of bird droppings, branches, and leaves, it is easy to block the rain gauge and affect the normal operation of the instrument. Use requires human maintenance on the equipment, and it is impossible to realize long-term unmanned automatic observation

For example, the Parsivel raindrop spectrometer, the sampling space is limited by the photoelectric array at the receiving end, and the spatial resolution is too low to detect light rain and drizzle; the FDl2P rain gauge that uses the principle of extinction scattering, the extinction coefficient is transmitted as a low-pass signal, which will be interfered by electromagnetic fields (airport); the 2DVD two-dimensional imaging rain gauge line scan camera developed by Schonhuber et al. only uses 512 photoelectric detection elements, so its resolution for small particles is low, and the physical resolution of the digital grid is 0.25mm. It cannot be measured for precipitation particles smaller than 0.5mm

In addition, existing optical rain gauges still have some common problems: ①The shape of raindrops is asymmetric when there is wind, and one-dimensional detection cannot accurately measure the size of asymmetric raindrops, and the shape of raindrops is calculated according to the spherical assumption, resulting in large errors; The light source mostly uses near-infrared light with a relatively long wavelength, so light diffraction causes large measurement errors; ③Because the thickness of the sheet light beam in the sampling area is different in the direction of light travel, for falling raindrops of the same size, When the position of the linear array detector is different, the measurement results are different, resulting in errors; ④ Since the detection light source will be affected by external conditions such as the environment during use, its output power will change with time, which will inevitably cause corresponding changes in imaging. Cause detection errors; ⑤Low scanning frequency of linear array detectors makes the time interval of scanning measurement too large, so that the representative scale of raindrops cannot be collected and measured, resulting in insufficient measurement accuracy; ⑥The pixel size of linear array detectors is too large, Measurement resolution is too low

Images