Disclosure of Invention
In order to solve the problems, the invention provides a sparse-cloth double-array-element double-frequency radar angle Lu Bangjie phase ambiguity-finding method and device, which can effectively improve the ambiguity-finding accuracy under the condition of low signal-to-noise ratio without increasing working frequency points.
The technical scheme for realizing the invention is as follows:
In a first aspect, the invention relates to a sparse-cloth double-array element double-frequency radar angle Lu Bangjie phase ambiguity method, which comprises the following specific processes:
Step 1, at the momentWhen in use, sliding storage is carried out on the non-fuzzy angle estimated valueAnd ascending the sequence to obtainAt the saidWhen the clustering result of (a) does not meet the requirement, continuing to store the non-fuzzy angle estimation value in a sliding way until the non-fuzzy angle estimation value meets the requirement, whereinRepresenting the total number of the set non-fuzzy angle estimation values;
step 2, at the momentWhen the current time and the last time angle estimation value are based, judging whether the current defuzzification is correct, correcting the incorrect defuzzification result, and setting a mark bit;
and 3, counting the situation of the zone bit, returning to the step 1 to start re-execution if the error times are larger than the set probability, otherwise returning to the step 2 to re-judge the angle estimated value at the next moment.
Optionally, the present invention uniformly divides the incident angle rangeIndividual classCalculation ofFall intoNumber of data of classRecordingMaximum value of (2)According to the describedJudging whether the clustering result meets the requirement.
Optionally, the clustering result of the present invention meets the requirement that:
,。
Optionally, the method of the invention judges whether the current defuzzification is correct based on the angle estimated value of the current moment and the last moment, specifically, calculates the absolute value of the difference between the angle estimated value of the current moment and the last momentIf (if)Less than a thresholdAnd if not, the current angle is considered to be correct, otherwise, the current angle is considered to be incorrect.
Optionally, the threshold of the inventionAccording to the maximum value of the target angle change rateDetermining, i.e. satisfyingWhereinA data update period.
Optionally, the error correcting disambiguation result of the present invention is:
setting the phase ambiguity estimation result at the previous timeCalculation of,;
According to the describedCalculating corresponding incidence angle estimation resultsThe method comprises the following steps:
Wherein, theRepresenting the phase difference measurement at the current time,For the wavelength of the sparse dual-array element emission signal,Representing array element spacing;
Take the closest angleA kind of electronic deviceCorresponding toCorrecting result for current moment phase ambiguityI.e.
。
Optionally, the invention sets the flag bit to 1 if the current time angle is correctly deblurred, otherwise sets the flag bit to 0, and stores the data flag bit in a length ofCounting the probability of error times in the array after each time of angle solution blurring is completedIf (if)And (3) considering that the current situation exceeds the error correction capability of the finite memory algorithm, returning to the step (1), otherwise, returning to the step (2).
The invention discloses a sparse-cloth double-array element double-frequency radar angle Lu Bangjie phase ambiguity measuring device, which comprises an ambiguity-free angle estimation module, a ambiguity resolution judgment correction module and a reset module;
A non-fuzzy angle estimation module for estimating the angle of the object at the momentWhen in use, sliding storage is carried out on the non-fuzzy angle estimated valueAnd ascending the sequence to obtainAt the saidWhen the clustering result of (a) does not meet the requirement, continuing to store the non-fuzzy angle estimation value in a sliding way until the non-fuzzy angle estimation value meets the requirement, whereinRepresenting the total number of the set non-fuzzy angle estimation values;
A module for correcting the fuzzy judgment, which is used for at the momentWhen the current time and the last time angle estimation value are based, judging whether the current defuzzification is correct, correcting the incorrect defuzzification result, and setting a mark bit;
And the resetting module is used for counting the situation of the zone bit, controlling the non-fuzzy angle estimation module to start to execute again if the error times are larger than the set probability, otherwise controlling the fuzzy judgment correction module to judge the angle estimation value at the next moment again.
The beneficial effects are that:
Firstly, the invention provides a sparse-cloth double-array-element double-frequency radar angle Lu Bangjie phase ambiguity-finding method, which can accurately identify and correct abnormal values in a phase ambiguity-finding process, and compared with the existing double-frequency searching method, the ambiguity-finding accuracy under the condition of low signal-to-noise ratio is greatly improved.
Second, compared with the existing multi-frequency searching method, the method does not need to increase the frequency point number, and is more beneficial to the engineering realization of a radar system.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
It is noted that the following embodiments and features of the embodiments may be combined with each other without conflict, and that all other embodiments obtained by persons of ordinary skill in the art without creative efforts based on the embodiments in the present disclosure are within the scope of protection of the present disclosure.
It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.
As shown in fig. 1, for using a sparse dual antenna element、Receiving the double-frequency signals, wherein the frequencies of the received signals are respectively、WhereinThe corresponding wavelengths are respectively、Array element、The distance is,Is the target angle of incidence.
When the frequency of the received signal isWhen the antenna array element is in use、Phase difference of received signalsIs that
(1)
Wherein, theIs an integer-period ambiguity value of the phase difference,Is in the main value intervalThe subscript 1 indicates that the received signal frequency is。
Similarly, when the frequency of the received signal isPhase difference at the timeIs that
(2)
The combined type (1) and (2) can be obtained
(3)
I.e.
(4)
As can be seen from formulas (1) and (2),、The value ranges of (a) are respectively
(5)
(6)
In practical engineering, phase measurement errors are generated due to the influence of thermal noise, and the phase difference measurement value containing the phase measurement errors is recorded as、
Substituting all integer values within the range satisfying the formula (5) into the formula (4) to obtainIs of (1)The method comprises the following steps:
(7)
constructing cost functions in solution spaceI.e.
(8)
Wherein, theTo round-down functions. The value in the solution space minimizing the cost function in the range of equation (6) is the phase ambiguity estimation result
(9)
Substituting formula (9) into formula (2) to obtain incidence angle estimation resultIs that
(10)
When the target distance is far, the signal-to-noise ratio of the received signal is low, which results in、When a large phase measurement error exists in the phase-to-phase ratio, the phase ambiguity estimation result is wrong.
In order to reduce the error probability of a phase ambiguity number estimation result and improve the measurement accuracy of an incident angle, the angle value output by the formula (10) is subjected to finite memory error correction processing to assist in resolving phase ambiguity, and the embodiment of the application provides a double-array element double-frequency radar angle measurement phase ambiguity resolving method.
Step 1, at the momentWhen in use, sliding storage is carried out on the non-fuzzy angle estimated valueAnd ascending the sequence to obtainAt the saidWhen the clustering result of (a) does not meet the requirement, continuing to store the non-fuzzy angle estimation value in a sliding way until the non-fuzzy angle estimation value meets the requirement, whereinRepresenting the total number of the set non-fuzzy angle estimation values;
step 2, at the momentWhen the current time and the last time angle estimation value are based, judging whether the current defuzzification is correct, correcting the incorrect defuzzification result, and setting a mark bit;
and 3, counting the situation of the zone bit, returning to the step 1 to start re-execution if the error times are larger than the set probability, otherwise returning to the step 2 to re-judge the angle estimated value at the next moment.
As shown in fig. 2, the following details of the above process are as follows:
And step 1, initializing clustering.
If the initial value of the finite memory algorithm is wrong, the error correction algorithm is caused to continuously error for a period of time until the initial value can be correctly obtained. In order to improve the reliability of the initial value of the finite memory algorithm, a data clustering method can be adopted to provide the initial value for the finite memory algorithm.
At the moment of timeIn this case, the blur-free angle estimation value obtained in the sliding storage formula (10),Representing the total number of the set non-fuzzy angle estimated values, and performing ascending order processing on the data to obtain
(11)
Uniform classification over a range of incidence anglesThe number of classifications hereinIs adjustable.
At the moment of timeWhen calculatingFall intoNumber of data of classRecordingMaximum value of (2). If it isWhereinTake the firstAnd if not, continuing to store the data in a sliding way until the initial value meeting the condition is obtained.
And 2, identifying and correcting abnormal values.
At the moment of timeComparing the angle estimation value at the current timeAngle estimation value with last timeOrder-making
(12)
If it isLess than a thresholdIf not, the angle solution at the current moment is considered to be incorrect and needs to be corrected, wherein the threshold is considered that the target angle cannot be suddenly changedCan be based on the maximum value of the target angle change rateDetermining, i.e. satisfyingWhereinA data update period.
If the angle estimated value at the current momentWhen the abrupt change is judged to occur, the estimation result of the phase ambiguity number at the current momentError correction is required and the phase ambiguity estimation result at the previous momentFor correct value, for correctOrder-making
(13)
Solving according to (10)Corresponding incidence angle estimation resultIs that
(14)
Take the closest angleA kind of electronic deviceCorresponding toCorrecting result for current moment phase ambiguityI.e.
(15)
And 3, recording an error correction process in a limited memory process, setting a flag bit to be 1 if the angle ambiguity resolution is correct at the current moment, and setting the flag bit to be 0 otherwise. Storing the data flag bit at a length ofCounting the probability of the number of errors in the array after each time the angle calculation is completed. If it isThe current situation is considered to be beyond the error correction capability of the current algorithm, at which point the memory should be reset and restarted.
The embodiment of the phase ambiguity measuring device for the sparse-cloth double-array element double-frequency radar angle Lu Bangjie comprises an unblurred angle estimating module, a deblurring judging and correcting module and a resetting module;
A non-fuzzy angle estimation module for estimating the angle of the object at the momentWhen in use, sliding storage is carried out on the non-fuzzy angle estimated valueAnd ascending the sequence to obtainAt the saidWhen the clustering result of (a) does not meet the requirement, continuing to store the non-fuzzy angle estimation value in a sliding way until the non-fuzzy angle estimation value meets the requirement, whereinRepresenting the total number of the set non-fuzzy angle estimation values;
A module for correcting the fuzzy judgment, which is used for at the momentWhen the current time and the last time angle estimation value are based, judging whether the current defuzzification is correct, correcting the incorrect defuzzification result, and setting a mark bit;
And the resetting module is used for counting the situation of the zone bit, controlling the non-fuzzy angle estimation module to start to execute again if the error times are larger than the set probability, otherwise controlling the fuzzy judgment correction module to judge the angle estimation value at the next moment again.
To verify the effectiveness of the present invention, the following simulation experiments were performed:
In this example, the interferometer system simulation parameters are as follows, antenna element spacingSignal frequency,The channel phase noise is set as statistically independent zero-mean Gaussian white noise. The target does uniform angular velocity motion with the angular velocity of 1 DEG/s within the range of-60 DEG to +60 DEG, and the phase deblurring accuracy of the method is respectively compared with the phase deblurring accuracy of the existing double-array element double-frequency, three-frequency, four-frequency and five-frequency deblurring methods, and the result is shown in figure 3. Compared with the existing double-frequency searching and deblurring method, the method has the advantage that the deblurring accuracy is remarkably improved. The three-frequency, four-frequency and five-frequency searching and deblurring methods can effectively improve the phase deblurring accuracy. When the signal-to-noise ratio is greater than 2dB, the three-frequency searching and defuzzifying correct rate is lower than that of the method, and when the signal-to-noise ratio is greater than 4dB, the method is equivalent to the five-frequency searching and defuzzifying method.
In summary, the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.