River flow measurement method based on radar signal

Abstract

The invention discloses a method for measuring river flow based on radar signals, which comprises the following steps: A) sending radar signals toward the water surface and receiving radar reflection signals through a river water level measuring device, and calculating the water level value of the river through the reflection signals; B) sending radar signals toward the water surface and receiving radar reflection signals through a river flow velocity measuring device, and calculating the flow velocity of the river through the reflection signals; C) calculating the river flow according to the river water level value, the river flow velocity and the river type. The river flow velocity and water level measuring method can measure the river flow in real time based on radar signals, has high measurement accuracy, and can also reduce work intensity and improve safety.

Description

Technical Field

[0001] The invention relates to the technical field of river channel monitoring, and in particular to a river channel flow measurement method based on radar signals. Background Art

[0002] Among the existing river flow velocity measuring devices, the flow velocity devices mainly include propeller-type and cup-type mechanical flow meters or acoustic Doppler flow profilers. Usually, the river flow velocity measuring device is loaded on a small boat, and the flow velocity of the river water in the river is measured by the boat sailing on the river, or the drifting state of the artificial tracer on the river is used to measure the flow velocity of the river water. The above two measurement methods have better measurement effects for calm water surfaces or water surfaces with flat banks, but for water surfaces with turbulent water flow or passing through cliffs, the above two measurement methods cannot be used to measure the flow velocity on the surface of the river. The above measurement method is contact-type. For the surface flow velocity measurement of liquids containing corrosive components or impurities such as sewage and mud, and the measurement of floods and major floods, contact measurement will be subject to many restrictions. The use of contact flow velocity measurement methods requires a large number of operators, and the measurement cycle is long, the measurement accuracy is low, and there are safety hazards for personnel measuring in dangerous rivers.

[0003] The traditional method of measuring water level is to set up a water gauge at the test section and manually observe the water level at regular intervals.

[0004] At present, the commonly used observation instruments mainly include float water level gauges, bubble water level gauges, vibrating string water level gauges, ultrasonic water level gauges and radar water level gauges. These observation instruments all have certain shortcomings. The float water level gauge requires the construction of a vertical shaft, the connecting pipe is silted up, and an inverted siphon needs to be processed. The inverted siphon needs to be vacuumed, which is costly and difficult to handle. Water level observation requires manual reading of a benchmark value in the river every day with a water ruler, and then marking it on the water level gauge as the benchmark value. The manual reading itself is affected by water waves and has large errors. Bubble and vibrating string water level gauges need to be buried underwater, which are greatly affected by water waves. At the same time, they are expensive and difficult to promote widely. The cost of civil engineering projects is high, and it is difficult to adapt to field working environments and large-scale promotion. Water level observation is greatly affected by instrument installation, ancillary facilities and weather, and the observation workload is large; most equipment does not solve the problem of instrument observation being affected by water waves. The automation capability of recording and organizing observation data is poor, and it is greatly affected by human factors. The measurement accuracy is poor, and the actual measurement error is difficult to meet the accuracy requirements. In the actual field environment, the water level measurement of natural rivers is difficult to synchronize with other hydrological elements such as flow due to many human factors. Therefore, the existing observation instruments have not fundamentally solved the problem of the impact of waves on water level observation.

[0005] Therefore, at this stage, there is an urgent need for a river flow measurement method that can measure the natural river flow in real time by contactlessly measuring the river water level and river flow velocity. Summary of the invention

[0006] The purpose of the present invention is to provide a river flow measurement method based on radar signals. The river flow velocity and water level measurement method can perform real-time measurement of river flow based on radar signals, has high measurement accuracy, can also reduce work intensity and improve safety.

[0007] In order to achieve the above object, the present invention provides a river flow measurement method based on radar signals, and the river flow measurement method comprises the following steps:

[0008] A) Sending radar signals toward the water surface and receiving radar reflected signals through the river water level measuring device, and calculating the water level value of the river through the reflected signals;

[0009] B) sending radar signals toward the water surface and receiving radar reflected signals through a river flow velocity measuring device, and calculating the flow velocity of the river through the reflected signals;

[0010] C) Calculate the river flow based on the river water level, river flow velocity and river type.

[0011] Preferably, the river water level measuring device comprises: a first radio frequency front-end circuit and a first signal processing module, wherein the first radio frequency front-end circuit is used to send radar signals vertically toward the water surface and receive radar reflection signals; wherein,

[0012] The method for measuring the river water level value includes the following steps:

[0013] A1) The first signal processing module removes the DC from the radar reflected signal, intercepts a section of the signal, performs a 2048-point FFT, and performs spectrum analysis according to the configured starting range of the measurement range;

[0014] A2) Find the maximum value of the spectrum within the effective segment and the sub-maxima on both sides of the maximum value of the spectrum, determine the frequency point to be found based on the parabola fitting method, and finally refine the spectrum through Chirp-z to obtain the accurate spectrum value and calculate the real-time water level height value.

[0015] Preferably, the method for measuring the water level value further comprises:

[0016] The real-time water level height value is stored in a fixed-length array for sliding storage, and the average value disAvg of the water level height value data at the fixed-length position is calculated.

[0017] Preferably, the method for measuring the water level value further comprises:

[0018] Calculate the difference between disAvg and the array average value disMean of the previously stored average value and take the absolute value disDiff, compare the absolute value disDiff with the jump threshold hopValue, when disDiff ≥ hopValue, the jump count value hopcnt is accumulated and added by 1, otherwise, the jump count value hopcnt is cleared;

[0019] When the jump count value hopcnt is equal to 0, disAvg is placed in the fixed-length array and its average value is calculated as the final output water level height;

[0020] When hopcnt is greater than 0 and less than the transition number threshold, disAvg is placed in a fixed-length array and the previously calculated distance is used as the final output water level height;

[0021] When hopcnt is greater than the transition count threshold, the transition count value hopcnt is reset to zero, and its average value is calculated as the final output water level height.

[0022] Preferably, the river flow velocity measuring device comprises: a second RF front-end circuit and a second signal processing module, wherein the second RF front-end circuit is used to send radar signals from the upper side of the river toward the water surface and receive radar reflection signals; wherein,

[0023] The method for measuring river flow velocity includes the following steps:

[0024] B1) The second signal processing module performs signal preprocessing on the radar reflection signal, intercepts a section of the signal, calculates the signal zero-crossing rate, and determines whether the collected signal is a useful signal;

[0025] B2) When the signal is a useful signal, perform a 1024-point FFT operation to find out whether the ratio of the maximum amplitude in the frequency domain to the average amplitude in the frequency domain exceeds the threshold, and again determine whether the collected signal is useful;

[0026] B3) When the signal is judged as a useful signal again, the frequency signals of the consecutive useful signals are saved in a first-in-first-out manner, the saved multiple frames of data are accumulated, and then the maximum frequency position is obtained. Then, Chirp-Z is used to refine the frequency according to the searched frequency value to obtain the final frequency, and the current flow rate value is calculated according to the flow rate calculation formula.

[0027] Preferably, the method for measuring river flow velocity also includes:

[0028] Put the real-time measured flow rate value into the corresponding array, sort the measurement results, intercept the data in the effective segment and average it to get the average flow rate V within a period of time now .

[0029] Preferably, the method for measuring river flow velocity also includes:

[0030] Sort the stored average flow rate values ​​and obtain the average flow rate value V of the data in the fixed-length array his , calculate the current average flow velocity V now The average velocity value V calculated in the array his The absolute value of the difference, diff_value, is compared with the jump value hop_value set by the system. When diff_value≥hop_value, the jump count value hop_cnt is accumulated and added by 1; otherwise, the jump count value hop_cnt is cleared;

[0031] When the accumulated hop_cnt is greater than the jump number threshold, hop_cnt is initialized to 0 and the current average flow rate V is now The data are stored in the average flow velocity array, sorted, and the average value of the fixed-length array is taken as the final displayed average flow velocity value;

[0032] When hop_cnt is less than the jump number threshold, the average value of the fixed-length data in the previous average flow rate value array is directly used as the final displayed average flow rate value.

[0033] Preferably, in step B2), before calculating the flow velocity, the influencing frequency domain range is processed in the frequency domain.

[0034] Preferably, in step B1), the method in which the second signal processing module performs signal preprocessing on the radar reflection signal at least includes: direct current removal and low-pass filtering.

[0035] Preferably, the channel type is pre-stored in the measurement system, and the channel type includes the cross-sectional specifications of the riverbed of the measured section. The measurement system calculates the cross-sectional area of ​​the river according to the current water level of the river, and calculates the channel flow according to the cross-sectional area and the flow rate of the river.

[0036] According to the above technical scheme, the river flow velocity and water level measurement method in the present invention can measure the river flow in real time based on radar signals, has high measurement accuracy, and can also reduce work intensity and improve safety.

[0037] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1It is a measurement status diagram of a preferred real-time mode of a river flow velocity measurement device;

[0040] Figure 2 It is a measurement status diagram of a river water level measuring device in an optimal real-time manner;

[0041] Figure 3 It is a flow chart of river water level calculation and jump processing;

[0042] Figure 4 It is a flow chart for river flow velocity calculation and jump processing. DETAILED DESCRIPTION

[0043] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0044] In the present invention, unless otherwise stated, directional words contained in terms such as "up, down, left, right, front, back, inside, outside" merely represent the orientation of the terms in normal usage, or are common names understood by those skilled in the art, and should not be regarded as limitations on the terms.

[0045] See also Figure 1-4 As shown, the present invention provides a river flow measurement method based on radar signals, and the river flow measurement method includes the following steps: A) sending radar signals toward the water surface and receiving radar reflection signals through a river water level measuring device, and calculating the water level value of the river through the reflection signals; B) sending radar signals toward the water surface and receiving radar reflection signals through a river flow velocity measuring device, and calculating the flow velocity of the river through the reflection signals; C) calculating the river flow according to the river water level value, river flow velocity and river type.

[0046] Through the implementation of the above technical solution, the river flow measurement method includes two parts: river water level measurement and river flow velocity measurement. The river water level height is measured by the river water level measuring device, and the river flow velocity water level measuring device measures the river flow velocity. The two measured parameters are combined with the selected river type to calculate the river flow. The river flow velocity water level measurement method can measure the river flow in real time based on radar signals, has high measurement accuracy, and can also reduce work intensity and improve safety.

[0047] Figure 2 This is a schematic diagram of the actual measurement scenario of the water level measuring device. Since the measurement results may fluctuate due to external interference, in order to solve this problem, the following method is used to calculate and resolve the impact of the fluctuation.

[0048] In this embodiment, in order to measure the accuracy of river flow, it is necessary to further accurately measure the water level of the river. The water level measuring device includes: a first RF front-end circuit and a first signal processing module, wherein the first RF front-end circuit is used to send a radar signal vertically toward the water surface and receive a radar reflection signal; wherein the method for measuring the water level value of the river includes the following steps: A1) the first signal processing module removes the DC processing of the radar reflection signal and intercepts a section of the signal for 2048-point FFT, and performs spectrum analysis according to the starting range of the configured measurement range; A2) finds the maximum value of the spectrum in the effective section and the secondary maximum values ​​on both sides of the maximum value of the spectrum, determines the frequency points to be found according to the parabola fitting method, and finally refines the spectrum through Chirp-z to obtain an accurate spectrum value, and calculates the real-time water level value. Since the water level in the river changes relatively slowly in a short period of time, in order to avoid excessive differences in the measured values ​​caused by environmental interference during the test, the above method can ensure the measurement accuracy of the water level in the river.

[0049] Furthermore, the water level measurement method also includes: storing the real-time water level height value in a fixed-length array, performing sliding storage, and calculating the average value disAvg of the water level height value data at the fixed-length position. By calculating the average value disAvg of the water level height value data at the fixed-length position, the height value measurement data of the river water level is more accurate. In a specific implementation, the length of the fixed-length array is set to 10.

[0050] Furthermore, in order to further improve the accuracy of the water level height and suppress the occurrence of water level measurement jumps, the water level measurement method also includes: calculating the difference between disAvg and the array average value disMean of the previously stored average value to obtain the absolute value disDiff, comparing the absolute value disDiff with the jump threshold hopValue, when disDiff≥hopValue, the jump count value hopcnt is accumulated and added by 1, otherwise, the jump count value hopcnt is cleared; when the jump count value hopcnt is equal to 0, disAvg is placed in the stored fixed-length array, and its average value is calculated as the final output water level height; when hopcnt is greater than 0 and less than the jump number threshold, disAvg is placed in the stored fixed-length array, and the previously calculated distance is used as the final output water level height; when hopcnt is greater than the jump number threshold, the jump count value hopcnt is cleared, and its average value is calculated as the final output water level height. Through the implementation of the above scheme, the measured water level height changes smoothly, and the measurement accuracy reaches 0.001m. In this implementation, the length of the array storing the average value is set to 5.

[0051] Figure 1The actual picture of the actual measurement scene of the velocity measurement device, the radar signal f emitted by the velocity measurement device, the river channel reflection echo f', f received by the velocity measurement device d is the Doppler difference frequency signal generated by the transmitted signal and the received signal, f d =|f-f'|, the angle between the signal emitted by the flow velocity measuring device and the liquid surface is θ, c is the propagation speed of the radar wave in the air, then the calculation formula for calculating the river flow velocity can be expressed as During the flow velocity calculation process, the reflected signal may be affected by external factors, causing data jumps in individual segments of the calculation result. In order to solve this problem, the following specific implementation method is used to achieve the effect of suppressing jumps in flow velocity measurement.

[0052] In this embodiment, in order to measure the accuracy of the river flow, it is necessary to further accurately measure the flow velocity of the river. The river flow velocity measuring device includes: a second RF front-end circuit and a second signal processing module, wherein the second RF front-end circuit is used to send a radar signal from the upper side of the river toward the water surface and receive a radar reflection signal; wherein the river flow velocity measurement method includes the following steps: B1) the second signal processing module performs signal preprocessing on the radar reflection signal and then intercepts a section of the signal to calculate the signal zero crossing rate, and determines whether the collected signal is a useful signal. If the signal is a useless signal, the collected data is invalid and the calculation result is ignored; B2) the second signal processing module performs signal preprocessing on the radar reflection signal and then intercepts a section of the signal to calculate the signal zero crossing rate, and determines whether the collected signal is a useful signal. If the signal is a useless signal, the collected data is invalid and the calculation result is ignored; 2) When the signal is a useful signal, perform a 1024-point FFT operation to find out whether the ratio of the maximum amplitude in the frequency domain to the average value of the frequency domain amplitude exceeds the threshold, and again determine whether the collected signal is useful, and take different signal result processing; B3) When the signal is again determined to be a useful signal, in order to avoid deviations in the frequency position search of a single measurement, the frequency signals of multiple consecutive useful signals are saved in a first-in-first-out manner, and the saved multiple frames of data are accumulated, and then the maximum frequency position is obtained, and then the frequency is refined using Chirp-Z according to the searched frequency value to obtain the final frequency, and the current flow rate value is calculated according to the flow rate calculation formula. Since the flow rate of water in the river changes relatively slowly in a short period of time, in order to avoid excessive differences in the measured values ​​caused by environmental interference during the test, the above method can ensure the accuracy of the flow rate measurement of the river.

[0053] In this embodiment, in order to calculate the accuracy of the flow velocity result, it is judged multiple times whether the obtained signal is a valid signal, and the zero crossing rate of the time domain signal and the ratio of the frequency domain maximum value to the frequency domain amplitude are used as the judgment basis.

[0054] Furthermore, in order to make the flow velocity measurement more stable, the method for measuring the flow velocity of a river channel also includes: placing the flow velocity value measured in real time into a corresponding array, sorting the measurement results, intercepting the data in the effective section and averaging to obtain the average flow velocity V within a period of time. nowIn one embodiment, the average flow rate V now The data length is set to 30.

[0055] Furthermore, in order to further improve the accuracy of river flow velocity measurement and suppress the occurrence of velocity value jumps, the river flow velocity measurement method also includes: sorting the stored average velocity values, and obtaining the average velocity value V of the data in the fixed-length array. his , calculate the current average flow velocity V now The average velocity value V calculated in the array his The absolute value of the difference, diff_value, is compared with the jump value hop_value set by the system. When diff_value ≥ hop_value, the jump count value hop_cnt is accumulated and added by 1; otherwise, the jump count value hop_cnt is cleared to zero; when the hop_cnt accumulation is greater than the jump count threshold, hop_cnt is initialized to 0, and the current average flow rate V now The data are stored in the average velocity storage array, sorted, and the average value of the fixed-length array is taken as the final average velocity value displayed; when hop_cnt is less than the jump number threshold, the average value of the fixed-length data of the previous average velocity value array is directly used as the final average velocity value displayed. In this embodiment, the length of the fixed-length array is 10, and the jump number threshold is 5. Through such implementation, the measured river velocity changes smoothly, and the measurement accuracy reaches 0.01m / s.

[0056] Furthermore, in order to reduce interference from the mains, rain, etc., in step B2), before calculating the flow rate, the frequency domain range that affects the flow rate is processed in the frequency domain. For example, the mains frequency interference, rain interference, and the maximum measurement speed influence are processed in the frequency domain.

[0057] Furthermore, in order to further optimize the radar reflection signal and improve the accuracy of river flow velocity measurement, in step B1), the method in which the second signal processing module performs signal preprocessing on the radar reflection signal at least includes: DC removal and low-pass filtering.

[0058] Furthermore, the channel type is pre-stored in the measurement system, and the channel type includes the cross-sectional specifications of the riverbed of the measured section. The measurement system calculates the cross-sectional area of ​​the river according to the current water level of the river, and calculates the flow of the river according to the cross-sectional area and the flow rate of the river. The specific calculation formula is selected according to the type of riverbed. For example, if the cross-sectional area of ​​the riverbed is rectangular, the cross-sectional area of ​​the river is obtained by multiplying the width of the riverbed by the water level of the river. When the riverbed is a trapezoid, the cross-sectional area of ​​the river is calculated according to the area formula of the trapezoid. Of course, the inclination degrees of the two sides of the trapezoid need to be preset in the system.

[0059] In the present invention, in the measurement of river flow velocity, in order to reduce the instability of the measurement result caused by a single-frame signal, the spectrum of a multi-frame signal is saved, and in the process of calculating the flow velocity, the multi-frame spectrum signal is used to accumulate and obtain the maximum value of the spectrum. In order to make the measured flow velocity result accurate and stable without large jumps, multiple storage, sorting, averaging, comparison and other methods are used to calculate the flow velocity using different methods according to different situations as the result output to ensure the accuracy of the measured flow velocity. The signal for measuring the water level can be analyzed according to the measurement range of the configuration, the range is clear, and external interference is avoided during the measurement process.

[0060] In the present invention, in the measurement of the river water level, the water level signal to be analyzed is the better segment signal of the intercepted reflection signal, and in the process of determining the frequency domain, a combination of parabola fitting and Chirp-Z is used to determine the frequency position, so that the obtained frequency position is more accurate and the calculated water level is more accurate. In the process of measuring the water level, multiple storage, sorting, averaging, comparison and other methods are used to calculate the water level according to different situations as the result output, so as to ensure the accuracy of the measured water level.

[0061] The final river flow needs to be calculated using the corresponding formula according to the river type, assuming that the flow rate and water level measured by the device are accurate. Ultimately, compared to the existing technology, the method of calculating flow rate and water level and the interference processing of the present invention can make river measurement more accurate and have higher measurement precision.

[0062] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0063] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0064] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for measuring river flow based on radar signals, characterized in that: The river flow measurement method comprises the following steps: A) Sending radar signals toward the water surface and receiving radar reflected signals through the river water level measuring device, and calculating the water level value of the river through the reflected signals; B) sending radar signals toward the water surface and receiving radar reflected signals through a river flow velocity measuring device, and calculating the flow velocity of the river through the reflected signals; C) Calculate the river flow according to the river water level, river flow velocity and river type; The river water level measuring device comprises: a first radio frequency front-end circuit and a first signal processing module, wherein the first radio frequency front-end circuit is used to send radar signals vertically toward the water surface and receive radar reflection signals; wherein, The method for measuring the river water level value includes the following steps: A1) The first signal processing module removes the DC from the radar reflected signal, intercepts a section of the signal, performs a 2048-point FFT, and performs spectrum analysis according to the configured starting range of the measurement range; A2) Find the maximum value of the spectrum in the effective section and the sub-maxima on both sides of the maximum value of the spectrum, determine the frequency point to be found according to the parabola fitting method, and finally refine the spectrum through Chirp-Z to obtain the accurate spectrum value and calculate the real-time water level height value; The water level measurement method also includes: The real-time water level height value is stored in a fixed-length array for sliding storage, and the average value disAvg of the water level height value data at the fixed-length position is calculated; The water level measurement method also includes: Calculate the difference between disAvg and the array average value disMean of the previously stored average value and take the absolute value disDiff, compare the absolute value disDiff with the jump threshold hopValue, when disDiff ≥ hopValue, the jump count value hopcnt is accumulated and added by 1, otherwise, the jump count value hopcnt is cleared; When the jump count value hopcnt is equal to 0, disAvg is placed in the fixed-length array and its average value is calculated as the final output water level height; When hopcnt is greater than 0 and less than the transition number threshold, disAvg is placed in a fixed-length array and the previously calculated distance is used as the final output water level height; When hopcnt is greater than the transition count threshold, the transition count value hopcnt is reset to zero, and its average value is calculated as the final output water level height; The river flow velocity measuring device comprises: a second RF front-end circuit and a second signal processing module, wherein the second RF front-end circuit is used to send a radar signal from the upper side of the river toward the water surface and receive a radar reflection signal; wherein the river flow velocity measuring method comprises the following steps: B1) The second signal processing module performs signal preprocessing on the radar reflection signal, intercepts a section of the signal, calculates the signal zero-crossing rate, and determines whether the collected signal is a useful signal; B2) When the signal is a useful signal, perform a 1024-point FFT operation to find out whether the ratio of the maximum amplitude in the frequency domain to the average amplitude in the frequency domain exceeds the threshold, and again determine whether the collected signal is useful; B3) When the signal is judged as a useful signal again, the frequency signals of the consecutive useful signals are saved in a first-in-first-out manner, the saved multiple frames of data are accumulated, and then the maximum frequency position is obtained, and then the frequency is refined using Chirp-Z according to the searched frequency value to obtain the final frequency, and the current flow velocity value is calculated according to the flow velocity calculation formula; Other methods for measuring river flow velocity include: Put the real-time measured flow rate value into the corresponding array, sort the measurement results, intercept the data in the effective section and average it to get the average flow rate Vnow within a period of time; Other methods for measuring river flow velocity include: Sort the stored average flow rate values, calculate the average flow rate value Vhis of the data in the fixed-length array, calculate the absolute value diff_value of the difference between the current average flow rate Vnow and the average flow rate value Vhis calculated in the array, and compare it with the jump value hop_value set by the system. When diff_value≥hop_value, the jump count value hop_cnt is accumulated and added by 1; otherwise, the jump count value hop_cnt calculated by the jump value is cleared; When the accumulated hop_cnt is greater than the transition number threshold, hop_cnt is initialized to 0, and the current average flow rate Vnow is stored in the average flow rate storage array, and then sorted, the average value of the fixed-length array is taken as the final displayed average flow rate value; When hop_cnt is less than the jump number threshold, the average value of the fixed-length data in the previous average flow rate value array is directly used as the final displayed average flow rate value.

2. The method for measuring river flow based on radar signals according to claim 1, characterized in that: In step B2), before calculating the flow velocity, the influencing frequency domain range is processed in the frequency domain.

3. The method for measuring river flow based on radar signals according to claim 1, characterized in that: In step B1), the method in which the second signal processing module performs signal preprocessing on the radar reflection signal at least includes: DC removal and low-pass filtering.

4. The method for measuring river flow based on radar signals according to claim 1, characterized in that: The channel type is pre-stored in the measurement system, and the channel type includes the cross-sectional specifications of the riverbed of the measured section. The measurement system calculates the cross-sectional area of ​​the river according to the current water level of the river, and calculates the channel flow according to the cross-sectional area and the flow rate of the river.

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