Radar cognitive reconnaissance processing method based on recognition before electromagnetic environment signal detection

Abstract

The invention provides a radar cognitive reconnaissance processing method based on recognition before electromagnetic environment signal detection. The method comprises the following steps: step 1, electromagnetic spectrum panoramic sensing; step 2, clutter noise floor calculation; step 3, identifying communication, radar and interference signals; step 4, generating a signal detection threshold of signal receiving; and step 5, channelized mask generation: under the condition that the channelized receiving and parameter measurement signal capability is limited, the detection, sorting and identification probabilities of a radar signal source are improved by sensing the electromagnetic environment.

Description

Technical Field

[0001] The present application relates to the field of radar reconnaissance processing technology, and in particular to a radar cognitive reconnaissance processing method based on pre-detection recognition of electromagnetic environment signals. Background Art

[0002] Electronic intelligence (ELINT) systems and electronic support (ESM) systems generally use superheterodyne receiving systems. In order to increase the probability of intercepting radar signals, superheterodyne receivers generally choose wider instantaneous bandwidths. The current mainstream channelized receiver bandwidths are between 500MHz and 4GHz. However, the ability of channelized receivers to process signals simultaneously is limited, and generally they can process 4 to 8 signals simultaneously. Electronic intelligence (ELINT) systems and electronic support (ESM) systems require full-band coverage, which is normally required to be 500MHz to 18GHz. As the competition for the electromagnetic spectrum becomes increasingly fierce, radar / communication / navigation and other radiation sources are competing for the use of spectrum resources. Therefore, electronic intelligence (ELINT) systems and electronic support (ESM) face extremely complex electromagnetic environments. There are not only radar radiation sources in their receiving channels, but also communication, navigation and high-power interference radiation sources. Communication and high-power interference radiation sources generally use continuous waves or large duty cycle signal waveforms to work.

[0003] Traditional electromagnetic compatibility methods generally use the method of trapping the microwave front end to ensure the normal operation of the receiving equipment, such as Figure 1 As shown. This method can ensure the normal operation of the reconnaissance equipment when the background signal is known or in a simple background. This method cannot ensure the normal operation of the reconnaissance equipment in a competitive and complex electromagnetic environment; therefore, the use of a more intelligent method to ensure the normal operation of the reconnaissance equipment has gradually become an urgent problem to be solved. Summary of the invention

[0004] The purpose of the present invention is to provide a cognitive reconnaissance processing method that is adaptable to complex electromagnetic environments, which is used to solve the problem that traditional electromagnetic compatibility methods cannot work properly in complex electromagnetic environments. By adding real-time spectrum monitoring and pre-processing identification modules for the electromagnetic environment, a reconnaissance strategy for electronic reconnaissance equipment is formulated; thereby improving the adaptability of electronic reconnaissance equipment to complex electromagnetic environments. The overall block diagram of a radar cognitive reconnaissance processing architecture based on pre-detection identification of electromagnetic environment signals is shown in the figure. Figure 2 shown.

[0005] A radar cognitive reconnaissance processing method based on pre-detection recognition of electromagnetic environment signals, the method comprising:

[0006] Step 1: Panoramic perception of the electromagnetic spectrum.

[0007] Calculate the FFT spectrum of the signal S(n):

[0008] S(f)=fft(S(n))

[0009] Accumulate the FFT spectrum and calculate the digital fluorescence data of the signal.

[0010] If the accumulation time has not yet arrived, the accumulation will continue. If the accumulation time has arrived, the digital fluorescence data will be sent to the front end for display and the accumulated digital fluorescence data will be cleared. The effect diagram of the calculated digital fluorescence data is as follows: Figure 3 shown.

[0011] Step 2: Calculate the noise floor

[0012] According to the bandwidth of the channelized receiver, the average value of the clutter energy within the receiver bandwidth is calculated;

[0013] For channels with signals, the calculation is based on -20dB of the signal power and the maximum value of the adjacent channel clutter power.

[0014] Step 3: Identify communication, radar, and interference signals.

[0015] The identification criteria are as follows:

[0016] If the signal is a continuous wave signal and the signal frequency band is the communication signal frequency band, it is judged as a communication signal; otherwise, it continues to determine whether there is amplitude modulation. If there is amplitude modulation, it is judged as a communication signal; otherwise, it is judged as a radar signal or an interference signal; if the type of intra-pulse modulation is unknown, it is judged as an interference signal;

[0017] If it is a pulse signal, determine whether the intra-pulse modulation type is no modulation, linear frequency modulation, nonlinear frequency modulation, frequency keying, two-phase encoding, four-phase encoding, and combined frequency keying and phase encoding. If so, it is judged as a radar signal, otherwise it is judged as a communication signal.

[0018] Step 4: Generate a signal detection threshold for signaled reception.

[0019] According to the average clutter energy calculated in step 2, the detection threshold is generated according to the signal-to-clutter ratio of 14dB;

[0020] Accepts manually generated detection thresholds. If the detection threshold is set manually, the manually set detection threshold is given priority.

[0021] Step 5: Channelization mask generation: When there are communication and interference signals in the channel, the channelization channel is closed; and the original data is sent to the refined analysis channel, and the time-frequency signal analysis is performed in the refined analysis channel, and then the parameter measurement is performed; the specific processing flow is as follows:

[0022] For the channelized processing channel, when communication and interference signals are detected in the channel, the channelized channel is closed; when multiple communication and interference signals exist, multiple channelized receiving channels are closed continuously;

[0023] When communication and interference signals are detected within the current bandwidth, the original data will be sent to the refined analysis channel, which will analyze the data through time-frequency analysis and complete parameter measurement, thereby completing the integrated processing of thunder, communication and interference signals.

[0024] The present invention recognizes radar, communication, navigation and interference signals in the electromagnetic environment by adding modules such as real-time spectrum monitoring and pre-processing identification in the electromagnetic environment, and realizes accurate detection of radar signals by controlling the detection threshold of each channel signal of the channelized receiver, channel opening and closing or single-channel signal separation, thereby improving the adaptability of radar cognitive reconnaissance in complex environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The electromagnetic compatibility method based on YIG notch provided in the embodiment of the present application;

[0026] Figure 2 An overall block diagram of the radar cognitive reconnaissance processing architecture based on pre-detection identification of electromagnetic environment signals provided in an embodiment of the present application;

[0027] Figure 3 A digital fluorescence image for real-time spectrum monitoring of the electromagnetic environment provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0029] The following first introduces the embodiments of the present application in conjunction with the accompanying drawings.

[0030] The present application provides a radar cognitive reconnaissance processing method based on pre-detection recognition of electromagnetic environment signals, the method comprising:

[0031] Step 1: Panoramic perception of the electromagnetic spectrum;

[0032] Step 2: Calculate the noise floor;

[0033] Step 3: Identify communication, radar, and interference signals;

[0034] Step 4: Generate a signal detection threshold for signaled reception;

[0035] Step 5: Channelization mask generation: When there are communication and interference signals in the channel, the channelization channel is closed; and the original data is sent to the refined analysis channel, and the time-frequency signal analysis is performed in the refined analysis channel before parameter measurement.

[0036] Step 1: Panoramic perception of the electromagnetic spectrum, including:

[0037] Calculate the FFT spectrum of the signal S(n):

[0038] S(f)=fft(S(n))

[0039] Accumulate the FFT spectrum and calculate the digital fluorescence data of the signal.

[0040] If the accumulation time has not yet arrived, the accumulation will continue. If the accumulation time has arrived, the digital fluorescence data will be sent to the front end for display, and the accumulated digital fluorescence data will be cleared.

[0041] Step 2: Calculate the noise floor, including:

[0042] According to the bandwidth of the channelized receiver, the average value of the clutter energy within the receiver bandwidth is calculated;

[0043] For channels with signals, the calculation is based on -20dB of the signal power and the maximum value of the adjacent channel clutter power.

[0044] Step 3: Identify communication, radar, and interference signals, including:

[0045] If the signal is a continuous wave signal and the signal frequency band is the communication signal frequency band, it is judged as a communication signal; otherwise, it continues to determine whether there is amplitude modulation. If there is amplitude modulation, it is judged as a communication signal; otherwise, it is judged as a radar signal or an interference signal; if the type of intra-pulse modulation is unknown, it is judged as an interference signal;

[0046] If it is a pulse signal, determine whether the intra-pulse modulation type is no modulation, linear frequency modulation, nonlinear frequency modulation, frequency keying, two-phase encoding, four-phase encoding, and combined frequency keying and phase encoding. If so, it is judged as a radar signal, otherwise it is judged as a communication signal.

[0047] Step 4: generating a signal detection threshold for signaled reception, including:

[0048] According to the average clutter energy calculated in step 2, the detection threshold is generated according to the signal-to-clutter ratio of 14dB;

[0049] Accepts manually generated detection thresholds. If the detection threshold is set manually, the manually set detection threshold is given priority.

[0050] Step 5: Channelization mask generation, including:

[0051] For the channelized processing channel, when communication and interference signals are detected in the channel, the channelized channel is closed; when multiple communication and interference signals exist, multiple channelized receiving channels are closed continuously;

[0052] When communication and interference signals are detected within the current bandwidth, the original data will be sent to the refined analysis channel, which will analyze the data through time-frequency analysis and complete parameter measurement, thereby completing the integrated processing of thunder, communication and interference signals.

[0053] In step 1, when performing panoramic perception of the electromagnetic spectrum, the current channelized frequency band can be monitored, or the entire frequency band can be monitored.

[0054] This application can also be applied to radar anti-interference identification to improve the radar's cognitive ability.

[0055] This application changes the original open-loop working mode and improves the adaptability to complex electromagnetic environments through the recognition of electromagnetic environments.

[0056] The above-described embodiments of the present application do not constitute a limitation on the protection scope of the present application.

Claims

1. A radar cognitive reconnaissance processing method based on pre-detection recognition of electromagnetic environment signals, characterized in that: The method comprises: Step 1: Panoramic perception of the electromagnetic spectrum; Step 2: Calculate the noise floor; Step 3: Identify communication, radar, and interference signals; Step 4: Generate a signal detection threshold for signaled reception; Step 5: Channelization mask generation: When there are communication and interference signals in the channel, the channelization channel is closed; and the original data is sent to the refined analysis channel, and after time-frequency signal analysis is performed in the refined analysis channel, parameter measurement is performed.

2. The method according to claim 1, characterized in that: Step 1: Panoramic perception of the electromagnetic spectrum, including: Calculate the FFT spectrum of the signal S(n): S(f)=fft(S(n)) Accumulate the FFT spectrum and calculate the digital fluorescence data of the signal. If the accumulation time has not yet arrived, the accumulation will continue. If the accumulation time has arrived, the digital fluorescence data will be sent to the front end for display, and the accumulated digital fluorescence data will be cleared.

3. The method according to claim 1, characterized in that Step 2: Calculate the noise floor, including: According to the bandwidth of the channelized receiver, the average value of the clutter energy within the receiver bandwidth is calculated; For channels with signals, the calculation is based on -20dB of the signal power and the maximum value of the adjacent channel clutter power.

4. The method according to claim 1, characterized in that: Step 3: Identify communication, radar, and interference signals, including: If the signal is a continuous wave signal and the signal frequency band is the communication signal frequency band, it is judged as a communication signal; otherwise, it continues to determine whether there is amplitude modulation. If there is amplitude modulation, it is judged as a communication signal; otherwise, it is judged as a radar signal or an interference signal; if the type of intra-pulse modulation is unknown, it is judged as an interference signal; If it is a pulse signal, determine whether the intra-pulse modulation type is no modulation, linear frequency modulation, nonlinear frequency modulation, frequency keying, two-phase encoding, four-phase encoding, and combined frequency keying and phase encoding. If so, it is judged as a radar signal, otherwise it is judged as a communication signal.

5. The method according to claim 1, characterized in that Step 4: generating a signal detection threshold for signaled reception, including: According to the average clutter energy calculated in step 2, the detection threshold is generated according to the signal-to-clutter ratio of 14dB; Accepts manually generated detection thresholds. If the detection threshold is set manually, the manually set detection threshold is given priority.

6. The method according to claim 1, characterized in that Step 5: Channelization mask generation, including: For the channelized processing channel, when communication and interference signals are detected in the channel, the channelized channel is closed; when multiple communication and interference signals exist, multiple channelized receiving channels are closed continuously; When communication and interference signals are detected within the current bandwidth, the original data will be sent to the refined analysis channel, which will analyze the data through time-frequency analysis and complete parameter measurement, thereby completing the integrated processing of thunder, communication and interference signals.

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