Dangerous weather auxiliary discrimination method for airborne weather radar

Abstract

The invention provides an airborne meteorological radar dangerous meteorological auxiliary discrimination method, and belongs to the technical field of airborne meteorological radars, and the method specifically comprises the steps: designing a combined waveform which is used for detecting a meteorological distribution situation in a wide range and detecting meteorological target speed and spectral width information in a key distance; secondly, a scanning mode different from that of conventional meteorological detection is adopted, so that required detection data can be obtained more effectively; and then processing echo data to obtain relevant information such as intensity, speed and spectral width of the meteorological target, and comprehensively judging the threat degree of weather to flight. According to the method, the existing meteorological detection capability of the radar is not influenced, the speed and spectral width information of the meteorological target in the key distance range can be detected and estimated with relatively high precision, the assessment capability of the radar on the threatening meteorological target can be effectively improved, and the flight safety is improved.

Description

Technical Field

[0001] The present application relates to the field of airborne weather radars, and in particular to a method for assisting in distinguishing dangerous weather conditions using airborne weather radars. Background Art

[0002] Airborne weather radar detects the weather distribution ahead of the aircraft route and presents it to the pilot through a display, assisting the pilot in route planning under complex weather conditions and ensuring flight safety. Therefore, the amount and accuracy of information displayed by the weather radar directly affects the pilot's observation and judgment.

[0003] Existing airborne radar meteorological detection uses a single meteorological detection waveform, which can only detect the intensity information of meteorological targets. However, the intensity of meteorological reflectivity is not the only criterion for judging the degree of meteorological threat to flight safety. By analyzing the characteristics of meteorological targets, it can be seen that different types of meteorological targets exhibit different speed and spectrum width characteristics. For example, the airflow activities inside convective clouds that have a serious impact on flight safety are violent and complex, while the airflow activities inside non-convective clouds are relatively simple. Therefore, speed and spectrum width information can be used as an important feature to assist in judging the degree of threat to flight safety caused by meteorological weather, especially severe convective weather. At the same time, the acquisition of environmental wind speed and direction also has a very significant advantage in tracking and predicting meteorological targets.

[0004] The waveforms and detection methods used by existing airborne meteorological radars make it difficult to obtain effective meteorological speed and spectral width information. For example, the currently widely used meteorological composite waveform, which is a composite waveform combining one meteorological pulse and four coherent turbulence pulses, can roughly estimate the turbulence spectral width. However, due to the small number of pulses and the low signal-to-noise ratio, the speed estimation accuracy is poor. At the same time, the distance distribution of meteorological targets is not taken into account. In the actual detection process, there are still influences such as distance and speed ambiguity, which seriously restricts the speed and spectral width estimation performance of meteorological targets. Summary of the invention

[0005] In view of this, the present application provides an auxiliary method for distinguishing dangerous weather by airborne weather radar, which solves the problems in the prior art. It does not affect the existing weather detection capability of the radar, but can also achieve high-precision detection and estimation of the speed and spectral width information of meteorological targets within a key distance range, which can effectively enhance the radar's assessment capability for threatening meteorological targets and improve flight safety.

[0006] The present application provides an airborne weather radar dangerous weather auxiliary identification method using the following technical solutions:

[0007] An airborne weather radar dangerous weather auxiliary identification method comprises the following steps:

[0008] The airborne meteorological radar transmits a combined waveform during meteorological detection, the combined waveform comprising a first waveform and a second waveform, the first waveform and the second waveform have different pulse repetition periods and pulse numbers, the second waveform is a coherent pulse, and the number of pulses is greater than 1;

[0009] Perform signal processing and data processing on the received first waveform and second waveform echo data respectively to obtain characteristic information of the meteorological target;

[0010] Based on the obtained meteorological target echo characteristic information, based on meteorological characteristics, and combined with the actual application scenarios of the aircraft flight phase, a comprehensive judgment is made on the degree of threat posed by the weather to the flight.

[0011] Optionally, the airborne weather radar is a mechanical scanning radar, and the scanning method is:

[0012] Single-line sequential scanning, the first waveform and the second waveform are transmitted and received alternately, or;

[0013] Double-line scanning, one line emits the first waveform and the other line emits the second waveform.

[0014] Optionally, the airborne weather radar is a phased array radar, and the scanning mode is:

[0015] Each beam transmits a first waveform and a second waveform respectively, and then switches to the next waveform, or;

[0016] First, use the first waveform to scan an azimuth line, process the echo data, obtain the target distribution information, and then transmit the second waveform in the azimuth where the echo is.

[0017] Optionally, the method of performing signal processing and data processing on the received first waveform echo data and second waveform echo data respectively includes:

[0018] Processing the first waveform echo data to obtain the meteorological position and intensity distribution information with unambiguous distance;

[0019] By processing the second waveform echo data of the same azimuth, the distance information of the echo can be obtained;

[0020] According to the meteorological distance information obtained by analyzing the first waveform, the echo of the second waveform is subjected to distance ambiguity resolution processing;

[0021] If the fuzzy echo and the unfuzzy echo of the meteorological target of the second waveform are not overlapped in distance, the fuzzy echo is defuzzified by distance, and the velocity and spectrum width information of the echo are extracted;

[0022] If the blurred echo and unambiguous echo of the meteorological target of the second waveform are aliased in the same distance segment, check the range-Doppler spectrum of the second waveform echo data to confirm whether the Doppler spectrum of the blurred echo and unambiguous echo of the meteorological target are aliased; if so, do not process the data in the aliased area; if not, extract the intensity and speed of the meteorological target in the range-Doppler domain, and perform ambiguity marking processing on the current direction to reflect that the waveform used for the current direction is not suitable for the current scene.

[0023] Optionally, if the blurred echo and unambiguous echo of the meteorological target of the second waveform are mixed in the same distance segment, the current position is fuzzy marked to reflect that the waveform used for the current position is not suitable for the current scene, and the second waveform of the azimuth position with the blurred mark is optimized according to the distribution of the meteorological target to obtain a new second waveform of the azimuth position with the blurred mark, which is used the next time the azimuth position is scanned to the azimuth position with the blurred mark.

[0024] Optionally, multiple features of the meteorological target are processed to obtain a feature vector, which is then weighted to estimate the degree of meteorological threat.

[0025] Optionally, quantify the threat level to obtain the threat level of weather to aircraft flight safety:

[0026]

[0027] Where: A and B are the threat level quantitative thresholds respectively.

[0028] Optionally, characteristic information of the meteorological target is obtained including distance, height, intensity, speed and spectrum width of the meteorological target.

[0029] In summary, this application includes the following beneficial technical effects:

[0030] The present application proposes a design and use method of a combined waveform, which can solve the influence of coherent waveform distance ambiguity while ensuring meteorological detection capability, and realize accurate estimation of meteorological target speed, spectral width and other information. Radar can use information reflecting meteorological characteristics such as the intensity, speed and spectral width of meteorological targets to assist in meteorological threat analysis, and predict the development trend and motion characteristics of dangerous meteorological targets, thereby improving the radar's detection performance and accurate warning capability for meteorological targets.

[0031] This application can take into account both airborne mechanical scanning radar and phased array radar, effectively improving the weather detection and assessment capabilities of airborne radar in different flight scenarios, further improving the detection and identification capabilities of dangerous weather, and improving the reliability of weather warnings.

[0032] The present application can be applied to the field of airborne weather radars and can be extended to multi-layer scanning and various types of airborne radar weather detection modes. The method of the present invention is easy to implement without changing the existing software and hardware conditions and has good market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a flow chart of the method for assisting in distinguishing dangerous weather conditions by airborne weather radar in this application. DETAILED DESCRIPTION

[0035] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0036] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0037] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0038] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show the components related to the present application rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0039] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects described may be practiced without these specific details.

[0040] The embodiment of the present application provides a method for assisting in distinguishing dangerous weather conditions using an airborne weather radar.

[0041] like Figure 1 As shown, a method for assisting in distinguishing dangerous weather with an airborne weather radar comprises the following steps:

[0042] The airborne meteorological radar transmits a combined waveform during meteorological detection. The combined waveform includes a first waveform and a second waveform. The pulse repetition period and the number of pulses of the first waveform and the second waveform are different. The second waveform is a coherent pulse, and the number of pulses is greater than 1. The pulse repetition period PRI 1 of the first waveform is greater than the pulse repetition period PRI 2 of the second waveform. PRI 1 is 4ms, which can realize unambiguous detection of long-distance meteorological targets. The corresponding unambiguous distance is 600km, and the meteorological intensity and position information within the entire detection range are mainly obtained; the number of pulses in the frame can be set according to demand, and the number of pulses in the frame is set to 1. When PRI 1 is set slightly smaller, the pulse hopping method can also be used to avoid distance ambiguity echo; the second waveform detects the area within the key distance range by emitting pulse-to-pulse coherent signals to obtain information such as the speed and spectrum width of the meteorological targets within the distance range; the pulse repetition period PRI 2 of the second waveform is relatively small, and the coherent pulse can be a single PRF or a dual PRF waveform; the number of pulses in the frame can be set according to demand. When the second waveform is initialized, a dual PRF waveform can be used to maintain an unambiguous distance to increase the speed detection range. Set PRI 2_1=1.2ms, PRI 2_2=1.5ms, and the number of pulses is set to 8 respectively; it can be modified according to actual conditions. Waveform parameters of the first waveform and the second waveform, such as pulse width, receiver bandwidth, etc., are set according to system detection requirements.

[0043] The received first waveform and second waveform echo data are respectively subjected to signal processing and data processing to obtain characteristic information of the meteorological target, including the distance, height, intensity, speed and spectrum width of the meteorological target. Before feature extraction, the meteorological echo should be judged to eliminate the influence of noise and clutter.

[0044] Based on the obtained meteorological target echo characteristic information, based on meteorological characteristics, and combined with the actual application scenarios of the aircraft flight phase, a comprehensive judgment is made on the degree of threat posed by the weather to the flight.

[0045] In one embodiment, the airborne weather radar is a mechanical scanning radar, and the scanning method is: single-line sequential scanning, with the first waveform and the second waveform being transmitted and received alternately.

[0046] In one embodiment, the airborne weather radar is a mechanical scanning radar, and the scanning method is: double-row scanning, one row transmits a first waveform, and the other row transmits a second waveform.

[0047] In one embodiment, the airborne weather radar is a phased array radar, and the scanning method is: each beam transmits a first waveform and a second waveform respectively, and then switches to the next wave position.

[0048] In one embodiment, the airborne weather radar is a phased array radar, and the scanning method is: first use a first waveform to scan an azimuth line, process the echo data to obtain the distribution information of the target, and then transmit the second waveform in the azimuth with the echo.

[0049] The method of performing signal processing and data processing on the received first waveform and second waveform echo data respectively includes: processing the first waveform echo data to obtain meteorological position and intensity distribution information with unambiguous distance; processing the second waveform echo data of the same direction to obtain the distance information of the echo, at which time, the distance information of the second waveform may be ambiguous; and performing distance ambiguity processing on the echo of the second waveform based on the meteorological distance information obtained by analyzing the first waveform.

[0050] If the ambiguous echo of the meteorological target of the second waveform is not overlapped with the unambiguous echo in terms of distance, the ambiguous echo is deambiguated by distance, and the velocity and spectrum width information of the echo are extracted.

[0051] If the fuzzy echo and unfuzzy echo of the meteorological target of the second waveform are aliased in the same distance segment, the range-Doppler spectrum of the second waveform echo data is checked to confirm whether the Doppler spectrum of the fuzzy echo and the unfuzzy echo of the meteorological target are aliased; if so, the data in the aliased area is not processed; if not, the intensity and speed of the meteorological target are extracted in the range-Doppler domain, and the current azimuth is fuzzy marked to reflect that the waveform used in the current azimuth is not suitable for the current scene, so as to facilitate the optimization of the waveform when scanning to the position next time. In the process of meteorological detection, the airborne meteorological radar adaptively optimizes and generates a new coherent waveform according to the meteorological distribution detected by the radar, the fuzzy mark obtained by data processing, and the echo speed information, so as to avoid the double fuzziness of the meteorological echo distance and speed, and improve the adaptability and detection accuracy of the coherent waveform in complex meteorological scenes. The new waveform is used to repeat the echo data processing and the acquisition of echo feature information to realize the detection and processing of the specified range and obtain the optimized meteorological detection results.

[0052] If the blurred echo and unambiguous echo of the meteorological target of the second waveform are mixed in the same distance segment, the current position is ambiguously marked to reflect that the waveform used for the current position is not suitable for the current scene. The second waveform of the azimuth position with the blurred mark is optimized according to the distribution of the meteorological target to obtain a new second waveform of the azimuth position with the blurred mark, which is used for the next scan to the azimuth position with the blurred mark.

[0053] After processing multiple features of meteorological targets, feature vectors are obtained, and weighted processing is performed to estimate the degree of meteorological threat.

[0054] The degree of weather threat can be estimated by weighting the echo characteristic information:

[0055]

[0056] Where: [T1 T2 T3...T N ] are normalized eigenvectors of meteorological echoes, N is the number of features; w1,w2,...w N is a weight vector. The weights corresponding to different features should be set according to the actual situation and should be able to well reflect the role of the feature in threat judgment.

[0057] The above formula can be used to calculate the threat level of each meteorological resolution unit, and then obtain the threat level of meteorological information in the entire detection area.

[0058] Quantify the threat level and obtain the threat level of weather to aircraft flight safety:

[0059]

[0060] Where: A and B are the threat level quantitative thresholds respectively.

[0061] At this point, the threat level assessment and threat level judgment of the current scanning line meteorological detection data have been realized, and warnings can be further displayed on the radar display to prompt pilots to distinguish dangers.

[0062] In one embodiment, for the echo of the jth sampling point at the i-th orientation, the threat level is calculated as follows:

[0063]

[0064] Wherein: [Z(i,j)H(i,j)V(i,j)W(i,j)R(i,j)] are the normalized feature vectors of the echo of the jth sampling point in the ith azimuth respectively; w=[w1,w2,...w5] is the weight vector. The weights corresponding to different features should be set according to the actual situation and should be able to well reflect the role of the feature in threat judgment. For example, the greater the intensity of the meteorological target, the higher the altitude, the more violent the internal airflow movement, the greater the speed, the larger the spectrum width, and the closer the distance, the greater the threat to the flight safety of the aircraft.

[0065] Assuming that the normalized eigenvector of the echo at the jth sampling point at the ith orientation is [0.90.90.70.850.8], and the weight vector w = [0.2, 0.25, 0.1, 0.25, 0.2] is selected, the threat level of the point is calculated to be 0.85.

[0066] Quantify the threat level and obtain the threat level of weather to aircraft flight safety:

[0067]

[0068] Where: A and B are the threat level quantitative thresholds respectively.

[0069] Assuming that A and B are set to 0.5 and 0.8 respectively, the threat level of the jth sampling point at the ith direction is 0.85, which corresponds to a threat level of 2, indicating that the weather there is a high potential danger. If danger levels 1 and 2 appear on a large scale on the radar display, the pilot should avoid them according to the display.

[0070] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for assisting in distinguishing dangerous weather using airborne weather radar, characterized in that: The steps include: The airborne meteorological radar transmits a combined waveform during meteorological detection, the combined waveform comprising a first waveform and a second waveform, the first waveform and the second waveform have different pulse repetition periods and pulse numbers, the second waveform is a coherent pulse, and the number of pulses is greater than 1; Performing signal processing and data processing on the received first waveform and second waveform echo data respectively to obtain characteristic information of the meteorological target; Based on the obtained meteorological target echo characteristic information, based on meteorological characteristics, and combined with the actual application scenarios of the aircraft flight phase, a comprehensive judgment is made on the degree of threat posed by the weather to the flight.

2. The airborne weather radar dangerous weather auxiliary identification method according to claim 1 is characterized in that: The airborne weather radar is a mechanical scanning radar, and the scanning method is: Single-line sequential scanning, the first waveform and the second waveform are transmitted and received alternately, or; Double-line scanning, one line emits the first waveform and the other line emits the second waveform.

3. The airborne weather radar dangerous weather auxiliary identification method according to claim 1 is characterized in that: The airborne weather radar is a phased array radar, and the scanning method is: Each beam transmits a first waveform and a second waveform respectively, and then switches to the next waveform, or; First, use the first waveform to scan an azimuth line, process the echo data, obtain the target distribution information, and then transmit the second waveform in the azimuth where the echo is.

4. The method for assisting in distinguishing dangerous weather using airborne weather radar according to claim 1, characterized in that: The method for performing signal processing and data processing on the received first waveform echo data and the received second waveform echo data respectively includes: Processing the first waveform echo data to obtain the meteorological position and intensity distribution information with unambiguous distance; By processing the second waveform echo data of the same azimuth, the distance information of the echo can be obtained; According to the meteorological distance information obtained by analyzing the first waveform, the echo of the second waveform is subjected to distance ambiguity resolution processing; If the fuzzy echo and the unfuzzy echo of the meteorological target of the second waveform are not overlapped in distance, the fuzzy echo is defuzzified by distance, and the velocity and spectrum width information of the echo are extracted; If the blurred echo and unambiguous echo of the meteorological target of the second waveform are aliased in the same distance segment, check the range-Doppler spectrum of the second waveform echo data to confirm whether the Doppler spectrum of the blurred echo and unambiguous echo of the meteorological target are aliased; if so, do not process the data in the aliased area; if not, extract the intensity and speed of the meteorological target in the range-Doppler domain, and perform ambiguity marking processing on the current direction to reflect that the waveform used for the current direction is not suitable for the current scene.

5. The method for assisting in distinguishing dangerous weather using airborne weather radar according to claim 4, characterized in that: If the blurred echo and unambiguous echo of the meteorological target of the second waveform are mixed in the same distance segment, the current position is ambiguously marked to reflect that the waveform used for the current position is not suitable for the current scene. The second waveform of the azimuth position with the blurred mark is optimized according to the distribution of the meteorological target to obtain a new second waveform of the azimuth position with the blurred mark, which is used for the next scan to the azimuth position with the blurred mark.

6. The method for assisting in distinguishing dangerous weather using airborne weather radar according to claim 1, characterized in that: After processing multiple features of meteorological targets, feature vectors are obtained, and weighted processing is performed to estimate the degree of meteorological threat.

7. The method for assisting in distinguishing dangerous weather using airborne weather radar according to claim 6, characterized in that: Quantify the threat level and obtain the threat level of weather to aircraft flight safety: Where: A and B are the threat level quantitative thresholds respectively.

8. The method for assisting in distinguishing dangerous weather using airborne weather radar according to claim 1, characterized in that: The characteristic information of meteorological targets includes the distance, height, intensity, speed and spectrum width of meteorological targets.

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