Rain, snow and freezing disaster sensing method, device, electronic equipment and storage medium

Abstract

The invention relates to the field of meteorological perception technology, and provides a rain, snow and freezing disaster perception method, device, electronic equipment and storage medium. The method comprises: inputting the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model, determining the atmospheric downlink radiation of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area, and eliminating the interference of water vapor and liquid water in clouds on high-frequency microwave signals; based on the corrected passive microwave brightness temperature combination of the target frequency, respectively performing snow accumulation identification and snow depth monitoring on a stable snow accumulation area in the target area; based on the corrected passive microwave brightness temperature, respectively obtaining the snow depth of a thick snow area and a shallow snow area in an unstable snow accumulation area in the target area through different microwave signal combinations, and obtaining the precipitation intensity and freezing intensity by using an equivalent temperature threshold and a high-frequency signal combination, thereby improving the accuracy of comprehensive perception of the rain, snow and freezing disaster situation in the target area.

Description

Technical Field

[0001] The present invention relates to the field of meteorological perception technology, and in particular to a method, device, electronic equipment and storage medium for sensing rain, snow and freezing disasters. Background Art

[0002] The existing methods in the meteorological disaster system have deficiencies in weather and meteorological monitoring and forecasting. There are few ground observation stations, and the forecasts are mainly forecasts of meteorological processes. There is a lack of perception of the state of atmospheric processes such as rain and snow, and they cannot fully reflect the intensity and scope of the disaster.

[0003] How to improve the accuracy of comprehensive perception of rain, snow and freezing disaster situations is an important issue that needs to be urgently addressed in the industry. Summary of the invention

[0004] The present invention provides a rain, snow and freezing disaster perception method, device, electronic equipment and storage medium, which are used to improve the accuracy of comprehensive perception of rain, snow and freezing disaster situations.

[0005] The present invention provides a method for sensing rain, snow and freezing disasters, comprising:

[0006] Inputting the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0007] Based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain a corrected passive microwave brightness temperature of the target frequency;

[0008] Based on the corrected passive microwave brightness temperature of the target frequency, it is determined whether the target area is in a disaster situation.

[0009] According to a rain, snow and freezing disaster perception method provided by the present invention, the target frequencies include a V polarization frequency of 18 GHz, a V polarization frequency of 23 GHz, a V polarization frequency of 37 GHz and a V polarization frequency of 89 GHz.

[0010] According to a rain, snow and freezing disaster perception method provided by the present invention, the passive microwave brightness temperature corrected based on the target frequency is used to determine whether the target area is in a disaster situation, including:

[0011] Determining that the target area is in a first area, the first area being an area north of the 0°C isotherm in January;

[0012] When (Tb_18V-Tb_89V)>12K, the target area is determined to be a snow area;

[0013] When (Tb_18V-Tb_89V)<=12K, the target area is determined to be a non-snow area;

[0014] Among them, Tb_18V is the corrected passive microwave brightness temperature of the V polarization frequency of 18 GHz, and Tb_89V is the corrected passive microwave brightness temperature of the V polarization frequency of 89 GHz.

[0015] According to a rain, snow and freezing disaster perception method provided by the present invention, after determining that the target area is a snowy area, the method further includes:

[0016] The snow depth in the first area is determined as:

[0017] SD=4.5×(Tb_18V-Tb_37V)+1.5;

[0018] Where SD is the snow depth and Tb_37V is the corrected passive microwave brightness temperature at the V-polarization frequency of 37 GHz.

[0019] According to a rain, snow and freezing disaster perception method provided by the present invention, the passive microwave brightness temperature corrected based on the target frequency is used to determine whether the target area is in a disaster situation, including:

[0020] Determining that the target area is in a second area, the second area being an area south of the 0°C isotherm in January;

[0021] Determine the surface equivalent temperature of the target area based on the corrected passive microwave brightness temperature of the target frequency, and determine whether the target area is a rain, snow or freezing area based on the surface equivalent temperature;

[0022] The equivalent surface temperature is:

[0023] T=59.14-0.38×Tb_18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15;

[0024] Where T is the surface equivalent temperature, Tb_18V is the corrected passive microwave brightness temperature with a V polarization frequency of 18 GHz, Tb_23V is the corrected passive microwave brightness temperature with a V polarization frequency of 23 GHz, Tb_37V is the corrected passive microwave brightness temperature with a V polarization frequency of 37 GHz, and Tb_89V is the corrected passive microwave brightness temperature with a V polarization frequency of 89 GHz.

[0025] According to a rain, snow and freezing disaster perception method provided by the present invention, determining whether the target area is a rain, snow and freezing area based on the surface equivalent temperature includes:

[0026] When T>7, the target area is determined to be a non-rain, snow and freezing area;

[0027] When T<=7, the target area is determined to be a rain, snow and freezing area.

[0028] According to a method for sensing rain, snow and freezing disasters provided by the present invention, after determining that the target area is a rain, snow and freezing area, the method further includes:

[0029] When the first preset condition is met, the snow depth in the thick snow area of ​​the target area and the snow depth in the thin snow area of ​​the target area are determined based on Tb_18V and Tb_37V, wherein the first preset condition is: within a preset time period, T<4 and (Tb_18V-Tb_89V)>-5;

[0030] When the first preset condition is not met, the freezing intensity of the target area or the precipitation intensity of the target area is determined based on Tb_18V and Tb_89V.

[0031] The present invention also provides a rain, snow and freezing disaster sensing device, comprising:

[0032] An atmospheric downlink radiation determination module is used to input the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0033] A correction module, for correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, so as to obtain the corrected passive microwave brightness temperature of the target frequency;

[0034] The disaster determination module is used to determine whether the target area is a disaster situation based on the corrected passive microwave brightness temperature of the target frequency.

[0035] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for sensing rain, snow, and freezing disasters as described above is implemented.

[0036] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the method for sensing rain, snow and freezing disasters as described above is implemented.

[0037] The rain, snow and freezing disaster perception method, device, electronic device and storage medium provided by the present invention determine the atmospheric downlink radiation of the target frequency through a one-dimensional microwave atmospheric radiation transmission model, and determine the corrected passive microwave brightness temperature of the target frequency based on the atmospheric downlink radiation to determine whether the target area is in a disaster situation. The ground and atmospheric microwave scattering characteristics during the rain, snow and freezing disaster process are realized, and the intensity of ground freezing rain and snow coverage is identified by integrating multiple bands. The passive microwave atmospheric correction technology is used to eliminate the interference of water vapor and liquid water in the cloud on the high-frequency microwave signal, so as to realize the accurate perception of rain, snow and freezing disasters in the target area and improve the accuracy of comprehensive perception of the rain, snow and freezing disaster situation in the target area. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 It is a flow chart of the rain, snow and freezing disaster perception method provided by the present invention.

[0040] Figure 2 It is a schematic diagram of the fitting results of microwave transmittance and atmospheric downward radiation provided by the present invention.

[0041] Figure 3 It is a schematic diagram of the brightness temperature atmospheric correction process provided by the present invention.

[0042] Figure 4 It is a schematic diagram of the snow depth determination decision process provided by the present invention.

[0043] Figure 5 It is a structural schematic diagram of the rain, snow and freezing disaster sensing device provided by the present invention.

[0044] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] The present invention proposes a method for sensing rain, snow and freezing disasters. Figure 1 This is a flow chart of the rain, snow and freezing disaster perception method provided by the present invention. Figure 1 The rain, snow and freezing disaster perception method provided by the present invention may include:

[0047] Step 110, inputting the passive microwave atmospheric transmittance of the target frequency in the target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0048] Step 120, based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correct the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain the corrected passive microwave brightness temperature of the target frequency;

[0049] Step 130: determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency.

[0050] The execution subject of the rain, snow and freezing disaster perception method provided by the present invention can be an electronic device, a component in an electronic device, an integrated circuit, or a chip. The electronic device can be a mobile electronic device or a non-mobile electronic device. Exemplarily, the mobile electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc. The non-mobile electronic device can be a server, a network attached storage (NAS), or a personal computer (PC), etc., which is not specifically limited by the present invention.

[0051] The following takes the rain, snow and freezing disaster perception method provided by the present invention executed by a computer as an example to explain the technical solution of the present invention in detail.

[0052] In step 110, the passive microwave atmospheric transmittance of the target frequency in the target area is input into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, where the target frequency is a frequency within the range of Ku band, Ka band or W band.

[0053] Among them, Ku band refers to the microwave frequency band with a frequency between 12 and 18 GHz (gigahertz) and a wavelength between 2.5 cm and 1.7 cm. It has the advantages of high speed, high capacity and high reliability. The downlink frequency range of Ku band is usually from 10.7 to 12.75 GHz, and the uplink frequency range is from 12.75 to 18.1 GHz. Due to the high frequency of Ku band, terrestrial microwave, very high frequency, high frequency, radio and television cannot interfere with it, so the electromagnetic environment is relatively clear.

[0054] The Ka band is a microwave band in the electromagnetic spectrum with a frequency range of 20 GHz to 40 GHz. The Ka band has the characteristics of wide available bandwidth, less interference and small equipment size. In practical applications, its frequency range is often close to but not necessarily completely covers the entire interval of 20 GHz to 40 GHz.

[0055] The frequency range of the W band is 75GHz to 110GHz. It has the following characteristics: shorter wavelength, higher frequency, can carry more information; stronger penetration, can better penetrate the atmosphere and troposphere; less susceptible to interference, less likely to interfere with electromagnetic waves in other bands.

[0056] The one-dimensional microwave atmospheric radiation transmission model is a mathematical or computational model that describes the transmission process of electromagnetic waves (especially microwaves) in the atmosphere. The core of this model is to understand the influence of the atmosphere on electromagnetic waves, including physical processes such as absorption, scattering, and reflection. The one-dimensional microwave atmospheric radiation transmission model is based on the physical principles of electromagnetic wave transmission in the atmosphere, and takes into account the effects of gas molecules, aerosols, clouds, etc. in the atmosphere on the scattering, absorption, and emission of electromagnetic waves.

[0057] Optionally, the target frequency may specifically be a V polarization frequency of 18 GHz, a V polarization frequency of 23 GHz, a V polarization frequency of 37 GHz, and a V polarization frequency of 89 GHz.

[0058] Among them, V polarization, also known as vertical polarization, means that the vibration direction of the radio wave is vertical. Specifically, when the satellite transmits a signal to the ground, if the vibration direction of its radio wave is perpendicular to the ground, it is called V polarization.

[0059] The target area is any area that needs to be aware of rain, snow and freezing disasters.

[0060] The passive microwave atmospheric transmittance of the target frequency in the target area can be the passive microwave atmospheric transmittance of 10 km per day. The passive microwave atmospheric downlink radiation of the target frequency at 10 km per day is estimated through a one-dimensional microwave atmospheric radiation transmission model.

[0061] Optionally, based on the one-dimensional atmospheric microwave radiation model, the microwave atmospheric transmittance and atmospheric downlink radiation can be simulated, and the fitting relationship between the atmospheric transmittance and atmospheric downlink radiation of the spaceborne microwaves at 18 GHz V polarization, 37 GHz V polarization and 89 GHz V polarization is obtained as follows:

[0062] For 18 GHz V polarization, ;

[0063] For 37GHz V polarization, ;

[0064] For 89GHz V polarization, ;

[0065] Among them, T b_down_18V， T b_down_37V， T b_down_89V They are the atmospheric downlink radiation of 18 GHz V polarization, 37 GHz V polarization and 89 GHz V polarization, Γ 18V ,Γ 37V and Γ 89V They are the atmospheric transmittances of 18 GHz V polarization, 37 GHz V polarization and 89 GHz V polarization. The fitting results of microwave transmittance and atmospheric downlink radiation are shown in Figure 2 The schematic diagram of the microwave transmittance and the atmospheric downward radiation fitting result provided by the present invention is shown as follows: wherein the horizontal axis Transmittance is the microwave transmittance, and the vertical axis Upwelling radiation is the atmospheric downward radiation fitting result.

[0066] According to the fitting formulas of microwave atmospheric transmittance and atmospheric downlink radiation of 18 GHz V polarization, 37 GHz V polarization and 89 GHz V polarization, and using the known daily 10 km atmospheric transmittance, the daily 10 km atmospheric downlink radiation values ​​of 18 GHz V polarization, 37 GHz V polarization and 89 GHz V polarization are calculated for the subsequent calculation of microwave atmospheric correction algorithm.

[0067] In step 120, based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, the passive microwave remote sensing original brightness temperature of the target frequency in the target area is corrected to obtain the corrected passive microwave brightness temperature of the target frequency.

[0068] Optionally, the passive microwave remote sensing original brightness temperature at the target frequency in the target area can be corrected by using the spaceborne passive microwave brightness temperature atmospheric correction algorithm based on radiation transmission. The specific correction process diagram can be as follows: Figure 3 The brightness temperature atmospheric correction process provided by the present invention is shown in the schematic diagram.

[0069] The specific implementation process is:

[0070] The formula derivation process of the spaceborne passive microwave brightness temperature atmospheric correction method based on radiation transmission is as follows:

[0071] Spaceborne microwave radiometer at frequency and observation angle Earth Observation Brightness Temperature It can be expressed as:

[0072] (1);

[0073] In formula (1), and are the frequency and the satellite observation angle, is the brightness temperature observed by the spaceborne microwave radiometer on Earth (in K), is the microwave atmospheric transmittance, is the land surface microwave emissivity, is the effective temperature of the atmosphere (in K), is the ground temperature (in K), The cosmic background radiation is 2.73K.

[0074] Ground-based microwave radiometer at the same frequency and observation angle Earth Observation Brightness Temperature for:

[0075] (2);

[0076] The atmospheric transmittance and effective atmospheric temperature It can be expressed as:

[0077] (3);

[0078] (4);

[0079] and is the optical thickness and absorption coefficient at the atmospheric height z, is the temperature in K at altitude z in the atmosphere.

[0080] Let (1)-(2)×(3), we can get (5):

[0081] (5);

[0082] At atmospheric height z=0, the observation angle The atmospheric downward radiation observed by the ground-based microwave radiometer for:

[0083] (6);

[0084] (7);

[0085] (8);

[0086] (9);

[0087] in , then formula (4) can be written as:

[0088] (10);

[0089] (11);

[0090] Substituting equation (11) into (5), we can obtain the passive microwave brightness temperature after atmospheric correction:

[0091] (12);

[0092] Based on equation (12), given the daily satellite-borne radiometer brightness temperature (such as the AMSR2 brightness temperature at 10 km), daily atmospheric downwelling radiation (10 km resolution), daily atmospheric transmittance (10 km), and T CB =2.73 K, the atmospheric-corrected daily AMSR2 passive microwave brightness temperatures at 18 GHz V polarization, 37 GHz V polarization, and 89 GHz V polarization frequencies can be directly calculated and used in the subsequent decision-making process for rain, snow, and freezing disasters.

[0093] In step 130, it is determined whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency.

[0094] Specifically, based on the analysis of historical disaster data, we can determine the performance characteristics of different disaster types (such as rain, snow, freezing, etc.) on V-polarized microwave brightness temperature data at different frequencies. Since microwaves of different frequencies have different penetration capabilities into the surface and atmosphere, different disaster types may exhibit different characteristics at different frequencies. For example, low-frequency microwaves (such as 18 GHz) may be more sensitive to soil moisture, while high-frequency microwaves (such as 89 GHz) may be more sensitive to surface roughness.

[0095] Therefore, based on the corrected passive microwave brightness temperature of the target frequency, the process of determining whether the target area is in a disaster situation can be realized.

[0096] The rain, snow and freezing disaster perception method provided by the embodiment of the present invention determines the atmospheric downlink radiation of the target frequency through a one-dimensional microwave atmospheric radiation transmission model, and determines the corrected passive microwave brightness temperature of the target frequency based on the atmospheric downlink radiation, and determines whether the target area is in a disaster situation. The ground and atmospheric microwave scattering characteristics during the rain, snow and freezing disaster process are realized, and the intensity of ground freezing rain and snow coverage is identified by integrating multiple bands. The passive microwave atmospheric correction technology is used to eliminate the interference of water vapor and liquid water in the cloud on the high-frequency microwave signal, so as to realize the accurate perception of rain, snow and freezing disasters in the target area and improve the accuracy of comprehensive perception of the rain, snow and freezing disaster situation in the target area.

[0097] In one embodiment, based on the corrected passive microwave brightness temperature of the target frequency, it is determined whether the target area is in a disaster situation, including: determining that the target area is in a first area, the first area is the area north of the 0°C isotherm in January; when (Tb_18V-Tb_89V)>12K, determining that the target area is a snowy area; when (Tb_18V-Tb_89V)<=12K, determining that the target area is a non-snowy area; wherein Tb_18V is the corrected passive microwave brightness temperature of the V polarization frequency of 18 GHz, and Tb_89V is the corrected passive microwave brightness temperature of the V polarization frequency of 89 GHz.

[0098] Based on the annual 0℃ isotherm in January, the region is divided into two research areas: the area north of the 0℃ isotherm in January is defined as the first area, and the area south of the 0℃ isotherm in January is defined as the second area. It can be understood that the first area is a colder area and the second area is a warmer area.

[0099] In the first region, the difference in brightness temperature between the atmospherically corrected passive microwave 18 GHz V polarization and 89 GHz V polarization is calculated and used to extract the snow cover extent:

[0100] (Tb_18V-Tb_89V)>12K, it is determined to be a snow area;

[0101] (Tb_18V-Tb_89V)<=12K, it is determined as a non-snow area;

[0102] Wherein, Tb_18V and Tb_89V are the brightness temperatures of 18 GHz V polarization and 89 GHz V polarization after atmospheric correction, respectively, and K stands for kilo.

[0103] It is understandable that passive microwave remote sensing satellites obtain information by measuring the microwave radiation emitted by the surface objects themselves. Due to the different physical properties of different substances (such as water, snow, vegetation, soil, etc.), such as dielectric constant, temperature, humidity, etc., there are also differences in the brightness temperature of microwave radiation emitted by them. This difference provides a basis for extracting the range of snow cover using passive microwave remote sensing technology. Snow cover has high albedo and low thermal conductivity, which give it unique radiation characteristics in the microwave band. Compared with other surface types such as soil and vegetation, there are significant differences in the radiation brightness temperature of snow cover in microwave bands such as 18GHz and 89GHz. In particular, when snow covers the surface, the microwave energy emitted by the underlying soil is scattered by snow particles, resulting in a significant change in brightness temperature. The scattering characteristics of V-polarized microwave radiation on the snow surface are different from those of horizontal polarization, which further enhances the difference in brightness temperature between snow cover and other surface types. Therefore, choosing V polarization for measurement helps to identify snow cover more accurately.

[0104] In an embodiment of the first area, after determining that the target area is a snow area, it also includes: determining the snow depth as: SD=4.5×(Tb_18V-Tb_37V)+1.5; wherein SD is the snow depth, and Tb_37V is the corrected passive microwave brightness temperature of the V polarization frequency of 37 GHz.

[0105] In the snowy area of ​​the first region, the snow depth (SD) is calculated using the brightness temperature difference between the atmospheric-corrected passive microwave 18 GHz V polarization and 37 GHz V polarization. The unit of SD is cm:

[0106] SD=4.5×(Tb_18V-Tb_37V)+1.5;

[0107] In one embodiment, based on the corrected passive microwave brightness temperature of the target frequency, determining whether the target area is in a disaster situation includes: determining that the target area is in a second area, and the second area is an area south of the 0°C isotherm in January; based on the corrected passive microwave brightness temperature of the target frequency, determining the surface equivalent temperature of the target area, and based on the surface equivalent temperature, determining whether the target area is a rain, snow and freezing area; the surface equivalent temperature is: T=59.14-0.38×Tb_ 18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15; wherein T is the surface equivalent temperature, Tb_18V is the corrected passive microwave brightness temperature with a V polarization frequency of 18 GHz, Tb_23V is the corrected passive microwave brightness temperature with a V polarization frequency of 23 GHz, Tb_37V is the corrected passive microwave brightness temperature with a V polarization frequency of 37 GHz, and Tb_89V is the corrected passive microwave brightness temperature with a V polarization frequency of 89 GHz.

[0108] Wherein, based on the surface equivalent temperature, determining whether the target area is a rain, snow or freezing area includes: in the case of T>7, determining that the target area is a non-rain, snow or freezing area;

[0109] When T<=7, the target area is determined to be a rain, snow and freezing area.

[0110] Specifically, passive microwave 18GHz V polarization, 23GHz V polarization, 37GHz H polarization and 89GHz V polarization are used to calculate the surface equivalent temperature T, and to determine the rain, snow and freezing areas:

[0111] T=59.14-0.38×Tb_18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15;

[0112] T>7, the second area is determined to be a non-rain, snow and freezing area, and no rain, snow and freezing disaster identification is performed;

[0113] T<=7, the second area is determined to be a rain, snow and freezing area.

[0114] In rainy and snowy weather, water droplets and ice crystals in the atmosphere will have a significant impact on microwave radiation. By monitoring the changes in microwave radiation in different frequency bands and polarizations, rainy and snowy weather areas can be identified. In particular, 37GHz H polarization is more sensitive to precipitation, while 89GHz V polarization can better reflect the presence of ice crystals.

[0115] Frozen areas (such as snow, frozen soil, etc.) have lower microwave radiation brightness temperatures. By comparing the microwave radiation brightness temperatures of different frequency bands and polarizations with the characteristic values ​​of known frozen areas, it is possible to determine whether the surface is frozen.

[0116] In one embodiment, after determining that the target area is a rain, snow or freezing area, it also includes: when a first preset condition is met, based on Tb_18V and Tb_37V, determining the snow depth in the thick snow area of ​​the target area and the snow depth in the thin snow area of ​​the target area, the first preset condition being: within a preset time period, T<4 and (Tb_18V-Tb_89V)>-5; when the first preset condition is not met, determining the freezing intensity of the target area or the precipitation intensity of the target area based on Tb_18V and Tb_89V.

[0117] Optionally, the specific determination process can be as follows Figure 4 The snow depth determination decision process provided by the present invention is shown in the schematic diagram.

[0118] When it is determined that the target area is in the rain, snow and freezing area of ​​the second area, the equivalent temperature T of the previous 5 days is calculated using the above-mentioned surface equivalent temperature T calculation formula, and it is determined whether T<4 for five consecutive days and (Tb_18V-Tb_89V)>-5;

[0119] If the above judgment is true for five consecutive days, T<4, and (Tb_18V-Tb_89V)>-5, it is judged as a snowy area, and the snow depth (cm) is calculated in the snowy area using passive microwave 18GHz V polarization, 37GHz V polarization (or 89GHz V polarization) after atmospheric correction. Before calculating the snow depth in the snowy area, first preliminarily determine whether the snow depth SD of the snowy area is greater than 15cm based on the latest snow depth data collected from ground stations and news reports.

[0120] If SD>15cm, the formula SD=4×(Tb_18V-Tb_37V)+1 is used, and the output is the snow depth in the thick snow area;

[0121] If SD<=15cm, use the formula SD=0.5×(Tb_37V-Tb_89V)+2, and the output is the snow depth in the light snow area.

[0122] If the above judgment is not true for five consecutive days, T<4, and (Tb_18V-Tb_89V)>-5, it is determined to be an icing / precipitation area, and the precipitation intensity / freezing intensity SD' (dimensionless) is calculated in the icing / precipitation area using passive microwave 18GHz V polarization and 89GHz V after atmospheric correction:

[0123] SD'=1.5×(Tb_18V-Tb_89V)+2>8, which is determined as precipitation intensity (dimensionless);

[0124] SD'=1.5×(Tb_18V-Tb_89V)+2<=8, determined as freezing intensity (dimensionless).

[0125] It is understandable that the high-frequency microwave channel based on spaceborne radiometers is highly sensitive to new snow / thin snow and has obvious responses to the atmosphere. Combined with the microwave low-frequency band combination for snow monitoring, a microwave atmospheric correction method is introduced. Aiming at the characteristics of low-temperature rain and snow processes, a decision tree method with multi-band combination and multi-threshold control is used to develop a new method for monitoring the snow depth, snow accumulation range and freezing intensity disaster situation based on spaceborne microwave radiometers (such as FengYun series / WMRI, GCOM-W1 / AMSR2).

[0126] This method can not only effectively monitor the range and thickness of thick snow (>15cm) and thin snow, but also sense the range and intensity of rain, snow and ice, and distinguish precipitation process information, forming a comprehensive judgment of (1) monitoring snow depth and snow range in snow accumulation areas, (2) freezing intensity information in freezing-affected areas, and (3) providing precipitation intensity and range information in precipitation areas. This method fully considers the problem of cloud cover when low-temperature rain and snow disasters occur, as well as the common new snow, thin snow and low-temperature freezing in snow disasters. The satellite-borne radiometer is used as the main data acquisition method, giving full play to the advantages of the sensor that is not blocked by clouds, can be observed continuously day and night, and has a high revisit rate. It develops all-weather, high-temporal-resolution satellite remote sensing monitoring that is sensitive to new and thin layers of snow and ice, and forms an all-weather rapid monitoring capability for freezing rain and snow disasters and snow accumulation emergency information.

[0127] This method fully considers the ground and atmospheric microwave scattering characteristics during new snow, thin snow and freezing processes, integrates the Ku, Ka and W bands to identify the intensity of ground freezing rain and snow cover, and uses passive microwave atmospheric correction technology to eliminate the interference of water vapor and liquid water in clouds on high-frequency microwave signals, thereby realizing all-weather low-temperature rain and snow monitoring.

[0128] Compared with the snow accumulation algorithms developed for high-latitude regions in related methods (such as the JAXA AMSR2 snow accumulation algorithm), it can better adapt to the scattering characteristics of new snow and thin snow, improve the detection capability of snow-covered area, especially overcome the influence of factors such as clouds and light, and achieve stable observation around the clock. It can meet the needs of timeliness and stability of disaster situation perception during emergency rescue work when freezing rain and snow disasters occur.

[0129] Figure 5 The structural diagram of the rain, snow and freezing disaster sensing device provided by the present invention is as follows: Figure 5 The device comprises:

[0130] The atmospheric downlink radiation determination module 510 is used to input the passive microwave atmospheric transmittance of the target frequency in the target area into the one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0131] The correction module 520 is used to correct the passive microwave remote sensing original brightness temperature of the target frequency in the target area based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency to obtain the corrected passive microwave brightness temperature of the target frequency;

[0132] The disaster determination module 530 is used to determine whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency.

[0133] The rain, snow and freezing disaster perception device provided by the embodiment of the present invention determines the atmospheric downward radiation of the target frequency through a one-dimensional microwave atmospheric radiation transmission model, and determines the corrected passive microwave brightness temperature of the target frequency based on the atmospheric downward radiation, and determines whether the target area is in a disaster situation. It realizes the ground and atmospheric microwave scattering characteristics during the rain, snow and freezing disaster process, integrates multiple bands to identify the intensity of ground freezing rain and snow coverage, and adopts passive microwave atmospheric correction technology to eliminate the interference of water vapor and liquid water in the cloud on the high-frequency microwave signal, realizes accurate perception of rain, snow and freezing disasters in the target area, and improves the accuracy of comprehensive perception of the rain, snow and freezing disaster situation in the target area.

[0134] In one embodiment, the atmospheric downlink radiation determination module 510 is specifically used to:

[0135] The target frequencies are determined to include a V polarization frequency of 18 GHz, a V polarization frequency of 23 GHz, a V polarization frequency of 37 GHz, and a V polarization frequency of 89 GHz.

[0136] In one embodiment, the disaster determination module 530 is specifically configured to:

[0137] The determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency includes:

[0138] Determining that the target area is in a first area, the first area being an area north of the 0°C isotherm in January;

[0139] When (Tb_18V-Tb_89V)>12K, the target area is determined to be a snow area;

[0140] When (Tb_18V-Tb_89V)<=12K, the target area is determined to be a non-snow area;

[0141] Among them, Tb_18V is the corrected passive microwave brightness temperature of the V polarization frequency of 18 GHz, and Tb_89V is the corrected passive microwave brightness temperature of the V polarization frequency of 89 GHz.

[0142] In one embodiment, the disaster determination module 530 is further specifically configured to:

[0143] After determining that the target area is a snow-covered area, the method further includes:

[0144] The snow depth in the snow accumulation area of ​​the first region is determined as:

[0145] SD=4.5×(Tb_18V-Tb_37V)+1.5;

[0146] Where SD is the snow depth and Tb_37V is the corrected passive microwave brightness temperature at the V-polarization frequency of 37 GHz.

[0147] In one embodiment, the disaster determination module 530 is further specifically configured to:

[0148] Determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency includes:

[0149] Determining that the target area is in a second area, the second area being an area south of the 0°C isotherm in January;

[0150] Determine the surface equivalent temperature of the target area based on the corrected passive microwave brightness temperature of the target frequency, and determine whether the target area is a rain, snow or freezing area based on the surface equivalent temperature;

[0151] The equivalent surface temperature is:

[0152] T=59.14-0.38×Tb_18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15;

[0153] Where T is the surface equivalent temperature, Tb_18V is the corrected passive microwave brightness temperature with a V polarization frequency of 18 GHz, Tb_23V is the corrected passive microwave brightness temperature with a V polarization frequency of 23 GHz, Tb_37V is the corrected passive microwave brightness temperature with a V polarization frequency of 37 GHz, and Tb_89V is the corrected passive microwave brightness temperature with a V polarization frequency of 89 GHz.

[0154] In one embodiment, the disaster determination module 530 is further specifically configured to:

[0155] The determining whether the target area is a rain, snow or freezing area based on the surface equivalent temperature includes:

[0156] In the case of T>7, the target area is determined to be a non-rain, snow and freezing area;

[0157] When T<=7, the target area is determined to be a rain, snow and freezing area.

[0158] In one embodiment, the disaster determination module 530 is further specifically used to: determine the snow depth in the thick snow area of ​​the target area and the snow depth in the thin snow area of ​​the target area based on Tb_18V and Tb_37V when a first preset condition is met, wherein the first preset condition is: within a preset time period, T<4 and (Tb_18V-Tb_89V)>-5;

[0159] When the first preset condition is not met, the freezing intensity of the target area or the precipitation intensity of the target area is determined based on Tb_18V and Tb_89V.

[0160] Figure 6 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 6 As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the rain, snow and freezing disaster perception method, which includes:

[0161] Inputting the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0162] Based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain a corrected passive microwave brightness temperature of the target frequency;

[0163] Based on the corrected passive microwave brightness temperature of the target frequency, it is determined whether the target area is in a disaster situation.

[0164] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0165] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, when the program instructions are executed by a computer, the computer can execute the rain, snow and freezing disaster perception method provided by the above methods, the method comprising:

[0166] Inputting the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0167] Based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain a corrected passive microwave brightness temperature of the target frequency;

[0168] Based on the corrected passive microwave brightness temperature of the target frequency, it is determined whether the target area is in a disaster situation.

[0169] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to perform the rain, snow, ice and freezing disaster perception method provided above, the method comprising:

[0170] Inputting the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band;

[0171] Based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain a corrected passive microwave brightness temperature of the target frequency;

[0172] Based on the corrected passive microwave brightness temperature of the target frequency, it is determined whether the target area is in a disaster situation.

[0173] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0174] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0175] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for sensing rain, snow and freezing disasters, characterized in that: The method comprises: Inputting the passive microwave atmospheric transmittance of the target frequency in the target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band, and the target frequency includes a V polarization frequency of 18 GHz, a V polarization frequency of 23 GHz, a V polarization frequency of 37 GHz and a V polarization frequency of 89 GHz; Based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area to obtain a corrected passive microwave brightness temperature of the target frequency; Determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency; Determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency includes: Determining that the target area is in a second area, the second area being an area south of the 0°C isotherm in January; Determine the surface equivalent temperature of the target area based on the corrected passive microwave brightness temperature of the target frequency, and determine whether the target area is a rain, snow or freezing area based on the surface equivalent temperature; The equivalent surface temperature is: T=59.14-0.38×Tb_18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15; Where T is the surface equivalent temperature, Tb_18V is the corrected passive microwave brightness temperature with a V polarization frequency of 18 GHz, Tb_23V is the corrected passive microwave brightness temperature with a V polarization frequency of 23 GHz, Tb_37V is the corrected passive microwave brightness temperature with a V polarization frequency of 37 GHz, and Tb_89V is the corrected passive microwave brightness temperature with a V polarization frequency of 89 GHz.

2. The method for sensing rain, snow and freezing disasters according to claim 1, characterized in that: The determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency includes: Determining that the target area is in a first area, the first area being an area north of the 0°C isotherm in January; When (Tb_18V-Tb_89V)>12K, the target area is determined to be a snow area; When (Tb_18V-Tb_89V)<=12K, the target area is determined to be a non-snow area; Among them, Tb_18V is the corrected passive microwave brightness temperature of the V polarization frequency of 18 GHz, and Tb_89V is the corrected passive microwave brightness temperature of the V polarization frequency of 89 GHz.

3. The method for sensing rain, snow and freezing disasters according to claim 2, characterized in that: After determining that the target area is a snow-covered area, the method further includes: The snow depth in the first area is determined as: SD=4.5×(Tb_18V-Tb_37V)+1.5; Where SD is the snow depth and Tb_37V is the corrected passive microwave brightness temperature at the V-polarization frequency of 37 GHz.

4. The method for sensing rain, snow and freezing disasters according to claim 1, characterized in that: The determining whether the target area is a rain, snow or freezing area based on the surface equivalent temperature includes: In the case of T>7, the target area is determined to be a non-rain, snow and freezing area; When T<=7, the target area is determined to be a rain, snow and freezing area.

5. The method for sensing rain, snow and freezing disasters according to claim 4, characterized in that: After determining that the target area is a rain, snow and freezing area, the method further includes: When the first preset condition is met, the snow depth in the thick snow area of ​​the target area and the snow depth in the thin snow area of ​​the target area are determined based on Tb_18V and Tb_37V, wherein the first preset condition is: within a preset time period, T<4 and (Tb_18V-Tb_89V)>-5; When the first preset condition is not met, the freezing intensity of the target area or the precipitation intensity of the target area is determined based on Tb_18V and Tb_89V.

6. A rain, snow and freezing disaster sensing device, characterized in that: include: An atmospheric downlink radiation determination module is used to input the passive microwave atmospheric transmittance of a target frequency in a target area into a one-dimensional microwave atmospheric radiation transmission model to determine the atmospheric downlink radiation of the target frequency, wherein the target frequency is a frequency within the range of the Ku band, the Ka band or the W band, and the target frequency includes a V polarization frequency of 18 GHz, a V polarization frequency of 23 GHz, a V polarization frequency of 37 GHz and a V polarization frequency of 89 GHz; A correction module, for correcting the passive microwave remote sensing original brightness temperature of the target frequency in the target area based on the atmospheric downlink radiation of the target frequency and the passive microwave atmospheric transmittance of the target frequency, so as to obtain the corrected passive microwave brightness temperature of the target frequency; A disaster determination module, configured to determine whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency; Determining whether the target area is in a disaster situation based on the corrected passive microwave brightness temperature of the target frequency includes: Determining that the target area is in a second area, the second area being an area south of the 0°C isotherm in January; Determine the surface equivalent temperature of the target area based on the corrected passive microwave brightness temperature of the target frequency, and determine whether the target area is a rain, snow or freezing area based on the surface equivalent temperature; The equivalent surface temperature is: T=59.14-0.38×Tb_18V+1.1×Tb_23V-0.41×Tb_37V+0.34×Tb_89V-273.15; Where T is the surface equivalent temperature, Tb_18V is the corrected passive microwave brightness temperature with a V polarization frequency of 18 GHz, Tb_23V is the corrected passive microwave brightness temperature with a V polarization frequency of 23 GHz, Tb_37V is the corrected passive microwave brightness temperature with a V polarization frequency of 37 GHz, and Tb_89V is the corrected passive microwave brightness temperature with a V polarization frequency of 89 GHz.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the rain, snow and freezing disaster perception method as described in any one of claims 1 to 5 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the rain, snow and freezing disaster perception method as described in any one of claims 1 to 5 is implemented.

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