CN112162233A - Two-dimensional wide-angle high-precision angle measurement method based on eight-port four-baseline radio frequency equipment - Google Patents

Abstract

The invention discloses a two-dimensional wide-angle high-precision angle measuring method based on eight-port four-baseline radio frequency equipment, which is characterized by comprising the following steps of: step 1, building eight-port four-baseline radio frequency equipment; step 2, determining a baseline interval and a frequency factor according to the angle range and the wavelength of the radiation source; step 3, determining the number of steps where the pitch angle of the radiation source is located; step 4, restoring the phase value of the actual pitch angle; step 5, calculating a radiation source pitch angle; step 6, determining the number of steps where the azimuth angle of the radiation source is located; step 7, restoring the actual azimuth angle phase value; and 8, calculating the azimuth angle of the radiation source. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency equipment is simple and convenient, has a wider angle measurement range and higher precision under the condition of the same cost or volume or number of antenna units, and can be used for engineering practice.

Description

Two-dimensional wide-angle high-precision angle measurement method based on eight-port four-baseline radio frequency equipment

Technical Field

The invention belongs to the technical field of radar radiation source direction finding methods, and particularly relates to a two-dimensional wide-angle high-precision angle finding method based on eight-port four-baseline radio frequency equipment.

Background

The radar radiation source direction finding technology can demodulate the direction of electromagnetic waves by utilizing the principle that the electromagnetic waves in different directions reach different amplitudes or phase responses generated by a direction finding antenna system. Depending on different factors, it can be classified into an amplitude method and a phase method. The phase method angle measurement utilizes the wave path difference between the electromagnetic wave signals radiated by a target and the antenna base line to measure the angle, namely, the direction of the signals is determined according to the relative phase difference of the same signals detected and received by a direction-finding antenna system, and then angle error signals are demodulated through the phase difference, and the antenna is driven to perform passive tracking on a radiation source. The relative phase difference is derived from the ratio of the relative wave path difference to the wavelength, and the principle is simpler. However, the phase method has a great disadvantage that measurement is blurred when the baseline width between the two antennas is too large, and a large measurement error is caused when the baseline width is too small. The novel wide-angle and high-precision angle measurement method researched by the technical scheme is based on phase method direction measurement, a set of simple and feasible novel angle measurement method is researched, and the problem of measurement ambiguity existing in the traditional phase method angle measurement is solved.

One, two base line angle measuring principle

At present, the angle measuring device based on the phase method direction measurement is mainly an interferometer, which uses the angle measuring principle of the double-baseline phase method, that is, uses the phase difference between echo signals received by a plurality of antennas to measure the angle. As shown in fig. 1, when the target radiates an electromagnetic wave signal in the θ direction, the electric wave reflected by the target reaching the receiving point is approximated to a plane wave. Because the base line interval between the two antennas is d, the signals received by the two antennas reach the difference of the wave path lengths of the two base lines, namely Delta R, so as to generate phase difference

The relationship between the phase difference and the baseline interval is:

where λ is the wavelength of the electromagnetic wave signal radiated by the target. The phase difference resulting from the wave path difference can be measured by a phase meter. Therefore, the angle θ of the electromagnetic wave signal radiated from the target can be derived from equation (1)

Knowing the wavelength of the electromagnetic wave signal radiated from the target, the azimuth of the target signal can be calculated from the equation (2) by using the phase difference measured by the phase meter.

Second, the problems of angle measurement blur and precision

The simple two-baseline phase method direction finding actually has a great problem, namely the measurement ambiguity problem.

From the equation (2), if the phase difference is small

Inaccurate value measurement will result in angle measurement errors. In order to research the relevant factors influencing the angle measurement precision, the two sides of the formula (1) are differentiated, namely

As can be seen from the formula (3), the reading accuracy is high

The angle measurement precision can be improved by the phase meter or by reducing the lambda/d value. In addition, when θ is 0, that is, when the target is in the antenna normal direction, the angle measurement error d θ is minimum, and when θ increases, d θ also increases, so that the range of θ is also limited to a certain extent to ensure a certain angle measurement accuracy. Although the angle measurement accuracy can be improved by reducing the value of λ/d, when the value of λ/d is reduced to a certain extent in a certain angle measurement range θ,

the value may exceed 2 pi, in which case

Where N is an integer, psi < 2 pi, and the actual reading of the phase meter is psi. Since the value of N is unknown, it is true

The value cannot be determined and a blurring problem (multivalue) occurs.

Third, the current method for solving the fuzzy problem

The measurement range is reduced when the measurement range is reduced, which means that the measurement accuracy and the measurement range are contradictory. The key to solve the contradiction is to solve the ambiguity problem, so how to deblur becomes a hot spot to be considered by applying the phase method to direction finding, and a plurality of methods for solving the ambiguity problem are researched and developed.

1. Stagger baseline deblurring

In order to solve the problem of direction finding ambiguity in the phase method direction finding, a direction finding method of a staggered baseline interferometer for solving the ambiguity problem by using the Chinese remainder theorem is provided by imitating the multi-frequency continuous wave distance measuring technology, the remainder theorem is applied to the direction finding of the interferometer, and a basic angle measuring schematic diagram of the ambiguity solving method is shown in FIG. 2.

An M-dimensional baseline interferometer with length of l_i(i-1, 2.., M-1), taking a base baseline l₀≤λ _min2, all base lines are l₀Integer multiple of (a) of

l₁:l₂:…:l_M-1＝m₁:m₂:…:m_M-1 (4)

Wherein m is_i(i ═ 1, 3.., M-1) is an integer

The interferometer measures the spacing between the base lines as l_iWhen corresponding to a phase difference of

And the actual phase difference is 2 pi l_isin theta/lambda in a relationship of

Wherein k is_iIndicates that the spacing between the base lines is l_iThe number of direction finding ambiguities in time.

Equation (5) is a same remainder with the same remainder in the real number domain with the divisor being an integerThe equation set, if two are selected to be co-prime, can be known according to the Chinese remainder theorem

Having a unique set of solutions k within the determined maximum unambiguous direction finding range_i. However, in this method, phase errors caused by antenna elements, microwave channels, receivers, and the like easily cause ambiguity resolution failure, and the calculation amount is large.

2. Virtual baseline disambiguation

The term "virtual baseline" refers to the difference in length between two different baselines. When the length difference is smaller than the half wavelength of the highest frequency of the broadband signal, the phase difference of the virtual baselines is the unambiguous phase. The schematic diagram is shown in FIG. 3, where the base line intervals of base lines 1 and 2 and base lines 2 and 3 are respectively l₁，l₂(l₂＞l₁) Subtracting two different baseline intervals can yield an interval of l₂-l₁The baseline interval and the corresponding phase difference of the virtual short baseline

In a relationship of

However, in the wide-angle direction finding, the virtual baseline method causes ambiguity resolution errors due to the influence of system errors and random errors, and even cannot resolve ambiguity.

3. Long and short baseline ambiguity resolution

The long and short baseline method is also called a three-baseline angle measurement method, and is implemented by using three baselines with proper two different baseline intervals, wherein one baseline is long and the other baseline is short. The schematic diagram is shown in fig. 4, 1 and 3 antennas with large intervals are used for obtaining high-precision measurement, and 1 and 2 antennas with small intervals are used for solving the measurement multivalue. Assuming that the electromagnetic wave signal with the target radiating direction theta is outwards, the distance between the antennas 1 and 2 is d₁₂The distance between the antennas 1,3 is d₁₃. By selecting d appropriately₁₂So that the phase difference between the signals received by the antennas 1 and 2 can satisfy the requirement in the angle measurement range

Read by the phase meter 1.

According to requirements, larger d is selected₁₃The phase difference of the signals received by the antennas 1,3 is

Where the phase meter 2 reads psi less than 2 pi, the following relationship may be used to determine the value of N

When the error of the phase meter 1 is within the acceptable range, the reading of the phase meter 1 is taken

And equation (10) can calculateThen, according to the formula (9), the value of N and the value of theta can be determined. d₁₃The/lambda value is larger, and the required precision is ensured.

Although the method for measuring the angle of the long and short baselines can solve the problem of ambiguity of direction measurement by using the short baselines and the problem of direction measurement range by using the long baselines, in the broadband direction measurement, when a target signal is a high-frequency signal, high requirements are required on the short baselines, and the method cannot be widely applied due to engineering limitation of physical realization of the short baselines.

Disclosure of Invention

The invention aims to provide a two-dimensional wide-angle high-precision angle measurement method based on eight-port four-baseline radio frequency equipment, and solves the problem that the existing angle measurement method cannot realize high measurement precision and wide measurement range at the same time.

The technical scheme adopted by the invention is as follows: the two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency equipment comprises the following steps of:

step 1, building eight-port four-baseline radio frequency equipment;

step 2, determining a baseline interval and a frequency factor according to the angle range and the wavelength of the radiation source;

step 3, determining the number of steps where the pitch angle of the radiation source is located;

step 4, restoring the phase value of the actual pitch angle;

step 5, calculating a radiation source pitch angle;

step 6, determining the number of steps where the azimuth angle of the radiation source is located;

step 7, restoring the actual azimuth angle phase value;

and 8, calculating the azimuth angle of the radiation source.

The invention has the beneficial effects that: the two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency equipment is simple and convenient, has a wider angle measurement range (can measure all angles) and higher precision under the condition of the same cost or volume or the number of antenna units, and can be used for engineering practice.

Drawings

FIG. 1 is a schematic diagram of a dual baseline goniometry;

FIG. 2 is a ragged baseline deblurring diagram;

FIG. 3 is a diagram of a virtual baseline deblurring principle;

FIG. 4 is a long and short baseline deblurring schematic;

FIG. 5 is a schematic diagram of the principle of eight-port angle measurement;

FIG. 6 is a test chart of two baselines of an antenna in an eight-port goniometric system;

FIG. 7 is a diagram showing the positional relationship between the electromagnetic wave to be measured and the antenna in the eight-port angle measurement system;

FIG. 8 is a schematic diagram of an eight port junction;

FIG. 9 shows the fuzzy phase value θ measured by an eight-port device when q is 0.8_EAnd theta_H；

FIG. 10 shows an angle value θ obtained by resolving the ambiguity phase values measured by an eight-port device at two frequencies when q is 0.8_E；

Fig. 11 shows angle values θ calculated at two frequencies when q is 0.8_ESubtracting to obtain a step map;

fig. 12 shows the difference θ between two frequencies when q is 0.8_EThe value is calculated by using the fuzzy phase value measured by the eight-port device to obtain an angle value theta_H；

Fig. 13 shows the difference θ between two frequencies when q is 0.8_EValue of fuzzy phase value theta measured by using eight-port device_HSubtracting the calculated angle value to obtain a step map;

fig. 14 shows a blur-free angle value θ obtained by reducing the measured angle value by the step method when q is 0.8_E；

In fig. 15, q is 0.8 and θ is different_EReducing the measured angle value by a step method under the value to obtain a non-fuzzy angle value theta_H；

Fig. 16 shows an unambiguous angle value θ obtained by reducing the measured angle value by the step method in the range of plus and minus 90 degrees when q is 0.8_E；

In fig. 17, q is 0.8 and θ is different_EWithin the range of plus or minus 90 degrees, the step method is utilized to reduce the measured angle value to obtain the non-fuzzy angle value theta_H；

Fig. 18 shows angle values θ obtained by solving for two frequencies at plus and minus 90 degrees when q is 0.6_E；

Fig. 19 shows angle values θ obtained by solving for two frequencies at plus and minus 90 degrees when q is 0.6_ESubtracting to obtain a step map;

fig. 20 shows an unambiguous angle value θ obtained by restoring the measured angle value by a step method at plus or minus 90 degrees when q is 0.6_E；

Fig. 21 shows θ at two frequencies of plus and minus 90 degrees when q is 0.6_EThe value is calculated by using the fuzzy phase value measured by the eight-port device to obtain an angle value theta_H；

Fig. 22 shows θ at two frequencies of plus or minus 90 degrees when q is 0.6_EThe value is calculated by using the fuzzy phase value measured by the eight-port device to obtain an angle value theta_HSubtracting to obtain a step map;

fig. 23 shows θ at two frequencies of plus and minus 90 degrees when q is 0.6_EThe value utilizes a step method to reduce the measured angle value to obtain a non-fuzzy angle value theta_H；

Fig. 24 shows an angle value θ obtained by solving for two frequencies at plus and minus 90 degrees when q is 0.3_ESubtracting to obtain a step map;

fig. 25 shows an unambiguous angle value θ obtained by reducing the measured angle value by a step method at plus or minus 90 degrees when q is 0.3_E；

Fig. 26 shows θ at two frequencies of plus and minus 90 degrees when q is 0.3_EThe value is calculated by using the fuzzy phase value measured by the eight-port device to obtain an angle value theta_HSubtracting to obtain a step map;

fig. 27 shows θ at two frequencies of plus and minus 90 degrees when q is 0.3_EThe value utilizes a step method to reduce the measured angle value to obtain a non-fuzzy angle value theta_H；

Fig. 28 shows angle values θ obtained by solving for two frequencies at plus and minus 90 degrees when q is 0.1_ESubtracting to obtain a step map;

fig. 29 is a non-blur angle value θ obtained by restoring the measured angle value by the step method at plus or minus 90 degrees when q is 0.1_E；

Fig. 30 shows θ at two frequencies of plus and minus 90 degrees when q is 0.1_EThe value is calculated by using the fuzzy phase value measured by the eight-port device to obtain an angle value theta_HSubtracting to obtain a step map;

fig. 31 shows θ at two frequencies of plus and minus 90 degrees when q is 0.1_EThe value utilizes a step method to reduce the measured angle value to obtain a non-fuzzy angle value theta_H。

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention provides a two-dimensional wide-angle high-precision angle measurement method based on eight-port four-baseline radio frequency equipment, which comprises the following steps of firstly building the eight-port four-baseline radio frequency equipment, namely providing the radio frequency equipment, wherein two ports are arranged in each direction around the radio frequency equipment, baselines are arranged on four ports of the radio frequency equipment opposite to the two directions, and the other four ports of the radio frequency equipment are respectively connected with a Schottky diode detector:

firstly, determining the length and frequency factor of the base line according to the angle range and wavelength of the radiation source

Firstly, a schematic diagram of the method is given, as shown in fig. 5, four large dots are a top view of the base line position of the antenna, the interval between the base lines 5 and 7 and the interval between the base lines 6 and 8 are d, the same four schottky diode detectors are respectively connected to the ports 1,2, 3 and 4, and the radiation source angle can be calculated through the reading of the detectors. Fig. 6 is a side view of two base wires of the antenna, and the other two base wires are the same as the side view of the antenna in the figure, but are perpendicular to the base wires.

Assuming an angle theta of an electromagnetic wave signal radiated from a target_EAnd theta_HWithin (-80 degrees and 80 degrees), d is 18mm for convenient engineering realization. Unlike the existing methods, the method of the invention only requires the ratio q to f of the two frequencies at which the system operates₁/f₂The frequency factor is fixed, so on the other hand, except some special values, the frequency factor can be arbitrarily taken, where q is 0.8, 24GHz is taken as the center frequency, two working frequencies are 21.3GHz and 26.7GHz, and the corresponding wavelength is λ₁14.1mm and λ₂＝11.2mm。

Second, determining the number of steps of the radiation source

The angle value with fuzzy value of two base line intervals at two frequencies can be measured by using an eight-port device

And

n is 1,2 and indicates the nth frequency. The principle of the steps proposed by the method of the invention is explained when incidentAngle of rotation

And

in the range of (-80 deg., 80 deg.), at different times

And

within the value range of (2), the measured angle difference values under different frequencies only contain limited fixed values called step values, and the steps are numbered in the sequence from left to right. So that the second step is to determine from the actually measured values

And

the number of the step.

Thirdly, restoring the actual phase value

Because each step corresponds to an angle interval, the step value can be reduced to an actual phase value by adopting a certain reduction criterion. For this purpose, a reduction criterion is established:

let L_mWhere m is E, H is the number of steps, X_mThe step position is numbered, the interval factor t is selected according to the specific condition of angle measurement, the manual adjustment of the 360-degree interval is carried out, and the phase of any one frequency measurement of two frequencies is selected

Having a real phase value

Is composed of

Simulation verification is performed according to the above-mentioned reduction process, and in this example, when t is equal to 1, the blurred phase value can be reduced to the actual phase value.

By using the formula (11), the actual phase of the reduction can be obtained

Fourthly, calculating the angle of the radiation source

After the actual phase value is obtained, the actual incident angle theta can be easily calculated according to the formula (2-1)_m。

The invention relates to a two-dimensional wide-angle high-precision angle measurement method based on eight-port four-baseline radio frequency equipment, which is based on the principle that:

one, eight port angle measuring principle

The antenna layout represented by the red dots in fig. 5 is drawn as a perspective view, as in fig. 7, with red lines

For plane waves arriving at the antenna, theta_EIs the pitch angle of the incoming wave, theta_HIs the azimuth angle of the incoming wave, beta_x、β_y、β_zThe projections of the incoming wave on the x, y and z axes respectively.

The plane wave that is set to reach the antenna can be expressed as:

wherein t represents the time of day in which,

a position vector is represented by a vector of positions,

represents a wave propagation vector, so the wave propagation vector can be decomposed into:

β_x＝β₀cosθ_Esinθ_H (13)

β_y＝β₀cosθ_Ecosθ_H (14)

β_z＝β₀sinθ_E (15)

it can be seen that, assuming the receiving unit 5 as the center of the coordinate system, it can be derived:

so in the coordinate system with the receiving unit 5 as the origin, the phase of the incident plane wave at each receiving unit can be expressed as:

now assume phi_E＝β₀dsinθ_EIs the phase difference between the antennas 5 and 7_H＝β₀dcosθ_Esinθ_HIs the phase difference between the antennas 6 and 8, i.e. + -.)_ECorresponding to the elevation angle phi_HFor azimuth. The above equation can be written as:

the eight-port network proposed by Zhanxuchun is composed of 4 180-degree directional couplers (ring bridge) and 1 90-degree item shifter, and the concept of incident wave and reflected wave in S parameter of microwave network is utilized, and the schematic diagram of eight ports is separately drawn as shown in FIG. 8, and then the eight ports have

According to the S parameter characteristics of the eight-port network

The combination of (28) and (29) has

The square of the modulus value is taken on both sides of each equation in equation (31), the ratio of the left-hand reflected voltage to the entrance voltage of the equation becomes the ratio of the reflected power to the incident power of each port, and the converted result is simplified as follows:

and due to P_i/P_k＝|S_ik|²Can be combined with (32)

So that x ═ phi can be solved_E+φ_H) (phi) 2 and y ═ y_E-φ_H) /2, according to phi_E＝β₀dsinθ_EAnd phi_H＝β₀dcosθ_Esinθ_HThe two angles can be solved as

θ_E、θ_HThe phase difference measured for the two baseline intervals respectively shows that the eight-port can measure the phase difference between the two baseline intervals, but the two phase differences have a fuzzy problem as the existing method at present, and therefore, a step concept is provided.

Second, step principle

Firstly, when the radiation source reaches the receiving device, the corresponding wavelengths lambda of the two frequencies₁And λ₂Next, the actual phase difference in both directions and the fuzzy phase value φ measured using an eight port device_EAnd phi_HAs shown in fig. 9. At this time can seeFor example, the two baseline intervals have phase ambiguity problems, and the ambiguity-free phase regions of different frequencies are different.

As can be seen from the observation formula (34), the incident angle θ is calculated_EAnd theta_HMust first find the unambiguous theta_EThe value is obtained. For this purpose, first, the angle theta is aligned_EAnd performing deblurring.

First, the measured ambiguity phase value is resolved into an angle value according to equation (34), and the relationship with the actual incident angle is shown in fig. 10. It can be seen that theta is measured at two frequencies_EThe value is only equal to the true value near 0 degrees, and the fuzzy characteristic exists after a certain range is exceeded, so that the angle measurement is inaccurate.

However, when the angle values measured at the two frequencies are subtracted from each other, a step diagram as shown in fig. 11 is obtained, and the value of each step is different, that is, the correspondence between the angle difference value measured at the two different frequencies and the real angle value of the callback signal is the step shape. However, each step is not very flat and has a small deviation, that is, the actual subtracted angular difference is not a constant value in the corresponding partial interval, but the number of the steps is approximately equal, and in order to make the step effect more obvious and to determine the steps more easily, the angular difference is allowed to fluctuate within the range of ± 1, so as to obtain 7 determined steps, the heights of which are-27, 9, -36, 0, 36, -9 and 27 respectively, and the steps are numbered from left to right from 1 to 7.

The second step of the process of the present invention is therefore based on θ_EThe step number is determined. By means of the different values of the steps, a wide angle theta of (-80 DEG, 80 DEG) can be achieved_EThe measurement is even the omnidirectional measurement of (-90 degrees and 90 degrees), and the high-precision advantage is ensured because the high-frequency test result can be adopted.

Now, the unambiguous elevation angle theta is obtained_EThe measured azimuth angle theta can be calculated according to the formula (34)_H. Note θ_HMeasured value of (a) is specified by_EInfluence of the value, so different θ_ECorresponding to different theta_HIs measured. Due to the function cos θ_EAbout theta_ESymmetric about 0, so_HIs also related to theta_ESymmetric about 0, so the equal spacing is chosen at this point to_E＝[-80，0]Of 17, solving for the measured theta using the second equation of equation (34)_HThe values are shown in fig. 12. The corresponding difference is shown in fig. 13, where θ can be seen_EThe difference maps are relatively straight step maps (or a straight line) and contain limited different step values.

At this time, though different theta_EThe value will result in a solution of θ using equation (34)_HDifferent measured values are obtained, but FIG. 12 tells that a step phenomenon still exists at the moment, so that the ambiguity resolution process is the same, and the same calculation method can be adopted.

The third step of the process according to the invention is therefore based on θ_HThe step number is determined. By different values of the step and the ambiguity-free theta calculated in the second step_EValue, a wide angle theta of (-80 deg., 80 deg.) can be achieved_EThe measurement is even the omnidirectional measurement of (-90 degrees and 90 degrees), and the high-precision advantage is ensured because the high-frequency test result can be adopted.

The two-dimensional wide-angle high-precision angle measuring method based on the eight-port four-baseline radio frequency equipment has the beneficial effects that:

high-precision merit evidence

The fuzzy angle value theta after the second step of reduction_EAngle with actual value theta_EThe reduction degree was observed by comparison, and the simulation result is shown in fig. 14. It can be seen that the reduced angle curve completely coincides with the actual angle curve, indicating the angle θ reduced according to this method_EAngle theta with respect to the actual_EThe method is completely equal, and the high-precision advantage is ensured due to the adoption of a high-frequency test result.

Similarly, the fuzzy angle value theta restored in the third step is_HAngle with actual value theta_HThe reduction degree was observed by comparison, and the simulation result is shown in fig. 15. It can be seen that the reduced angle curve completely coincides with the actual angle curve, indicating the angle θ reduced according to this method_HAngle theta with respect to the actual_HThe method is completely equal, and the high-precision advantage is ensured due to the adoption of a high-frequency test result.

Two, wide angle merit evidence

The measurement of the incident angle in the range of (-80 deg., 80 deg.) was discussed above, but it has not been proven that the method can measure the incident angle in the range of (-90 deg., 80 deg.) and (80 deg., 90 deg.). The maximum goniometric range of the method of the invention is investigated next.

Therefore, only the incident angle needs to be expanded to (-90 degrees and 90 degrees), and then the angle measurement principle is simulated, so that the incident angle in the interval of (-90 degrees and 90 degrees can be measured under a feasible frequency factor q, that is, the method can measure targets with all angles in the space, and the simulation result is shown in fig. 16 and 17.

In conclusion, the method can be realized in physical practice, and the incident angle in a wide angle range can be measured with high precision.

Examples

This section illustrates the selection of the frequency factor q and the interval factor t.

The simulation condition of the condition that the frequency factor q is 0.8 is given above, the frequency factors are assigned one by one, and the angle measurement principle of different frequency factors is simulated and verified one by one.

When q is 0.6, let λ₁16.6mm and λ₂＝10mm

The fuzzy phase theta measured at two frequencies is obtained from equation (1)_EAnd the fuzzy phase theta is corrected by using the first expression of the expression (34)_EResolving to obtain the angle value theta with ambiguity tested at the moment_EAs shown in fig. 18.

The two measured angle values are subtracted to find the step, which is shown in fig. 19. The number of steps is 7, namely-11, 21, -32, 0, 32, -21 and 11. To restore the actual phase theta_EWhen t is 1, the reduction result is shown in fig. 20. As a result of observation, the phase θ after reduction was found_EThe two curves are completely consistent with the actual phase, and the reduction phase theta is illustrated_EWith the actual phase theta_EExactly equal, ambiguous phase θ_EThe reduction is successful.

Reuse of reduced theta_EAnd measured theta_HValue, according to the second expression of expression (34), on the blur phase θ_HResolving to obtain the angle value theta with ambiguity tested at the moment_HAs shown in fig. 21. The two measured angle values are subtracted to find the step, which is shown in fig. 22. At this time, different theta_EAlthough the values correspond to different orders, it is clear from the foregoing that it is entirely possible to deblur these cases with one program. To restore the actual phase theta_HWhen t is 1, the reduction result is shown in fig. 23. As a result of observation, the phase θ after reduction was found_HThe two curves are completely consistent with the actual phase, and the reduction phase theta is illustrated_HWith the actual phase theta_HExactly equal, ambiguous phase θ_HThe reduction is successful.

Therefore, the method of the present invention is effective when the frequency factor q is 0.6.

When q is 0.3, let λ₁27.1mm and λ₂＝8.1mm

Still according to the above method, a step map is obtained as shown in fig. 24 and 26, and when t is 2, the angle value calculated by the reduction phase is also completely equal to the actual angle value of incidence, and the result is shown in fig. 25 and 27. When q is 0.3, the method of the present invention is effective.

When q is 0.1, let λ₁68.8mm and λ₂＝6.9mm

Still according to the above method, a step map is obtained as shown in fig. 28 and fig. 30, and when t is taken to be 3, the angle value calculated by the reduction phase is also completely equal to the actual incident angle value, and the result is shown in fig. 29 and fig. 31. When q is 0.1, the method of the present invention is effective.

Fourthly, summarize

And then, taking other values for q, and simulating one by one according to the process, wherein simulation results are not listed one by one.

And determining the value range of k as (0,1), scanning k at intervals of 0.1, and performing multiple times of simulation to obtain the following conclusion.

When q is equal to (0,1), the frequency factor can be measured by the method of the invention.

Further, by the generalization, the interval factor t is 3 when q ∈ (0,0.2), 2 when q ∈ (0.2,0.3), and 1 when q ∈ (0.3, 1).

Claims (9)

1. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency equipment is characterized by comprising the following steps of:

step 1, building eight-port four-baseline radio frequency equipment;

step 2, determining a baseline interval and a frequency factor according to the angle range and the wavelength of the radiation source;

step 3, determining the number of steps where the pitch angle of the radiation source is located;

step 4, restoring the phase value of the actual pitch angle;

step 5, calculating a radiation source pitch angle;

step 6, determining the number of steps where the azimuth angle of the radiation source is located;

step 7, restoring the actual azimuth angle phase value;

and 8, calculating the azimuth angle of the radiation source.

2. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 1, wherein the step 1 specifically comprises: providing radio frequency equipment, wherein two ports are arranged in each direction around the radio frequency equipment, base lines are arranged on four ports of the radio frequency equipment relative to the two directions, and the other four ports of the radio frequency equipment are respectively connected with a Schottky diode detector.

3. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 2, wherein the step 2 specifically comprises: according to the angle range and the wavelength of the dual-frequency radiation source, the ratio of two frequencies of the radiation source is determined as a frequency factor q, and any distance larger than the size of an antenna receiving the radiation source is selected as a base line interval d between every two opposite base lines.

4. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 3, wherein the step 3 specifically comprises:

step 3.1, resolving all fuzzy pitch angle values theta which can be measured under two frequencies when the radiation source is in all angles in the angle range by utilizing a first expression of the expression (34)_E1And theta_E2The subscripted numbers 1 and 2 denote a first frequency and a second frequency;

in the formula (34), x is (phi)_E+φ_H) (phi) 2 and y ═ y_E-φ_H) [ 2 ] can be calculated from the following equation (33):

in the formula (33), S_i5＝P_i/P5，i＝1,2,3,4；P_iThe signal power output by the Schottky diode detector connected with the port i of the radio frequency equipment is P5, and the signal power received by the base line connected with the port 5 of the radio frequency equipment is P5;

step 3.2, subtracting the fuzzy pitch angle values under the two frequencies, namely theta_E1-θ_E2Obtaining a step map of a pitch angle, wherein the total number of steps is L_EThe steps are numbered according to the relationship from small to large of the corresponding radiation source angle and are 1,2, … and L_E；

Step 3.3, measuring and calculating fuzzy pitch angle difference theta 'corresponding to the actual radiation source under two baseline intervals by adopting eight-port four-baseline dual-frequency radio frequency equipment and the first equation of equation (34)'_E1-θ′_E2The value is the actual step value;

step 3.4, mapping the actual step value obtained in the step 3.3 and the step map obtained in the step 3.2Obtaining the actual step number X_E。

5. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 4, wherein the step 4 specifically comprises:

step 4.1, selecting the phase measured by any one of the two frequencies

n is 1,2 denotes the nth frequency;

step 4.2, the actual phase value is obtained through the following formula (11-1)

In the formula (11-1), t is an interval factor, and when q ∈ (0,0.2), the interval factor t becomes 3, when q ∈ (0.2,0.3), the interval factor t becomes 2, and when q ∈ (0.3,1), the interval factor t becomes 1.

6. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 5, wherein the step 5 specifically comprises: according to the actual phase value obtained in step 4

The radiation source pitch angle theta is obtained through the formula (2-1-1)_E：

7. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 6, wherein the step 6 specifically comprises:

step 6.1, utilizing the pitch angle theta of the non-fuzzy radiation source obtained in the step 5_EAnd a second equation (34) for solving all ambiguous azimuth values θ that are possible to measure at two frequencies at all angles of the radiation source angular range_H1And theta_H2The subscripted numbers 1 and 2 denote a first frequency and a second frequency;

step 6.2, subtracting the fuzzy azimuth angle values under the two frequencies, namely theta_H1-θ_H2To obtain the actual pitch angle theta_EStep diagram of lower azimuth angle, total number of steps is L_HThe steps are numbered according to the relationship from small to large of the corresponding radiation source angle and are 1,2, … and L_H；

And 6.3, measuring and calculating fuzzy azimuth angle difference theta 'corresponding to the actual radiation source under two baseline intervals by adopting an eight-port four-baseline dual-frequency radio frequency device and a second equation of the equation (34)'_H1-θ′_H2The value is the actual step value;

step 6.4, mapping the actual step value obtained in the step 6.3 and the step map obtained in the step 6.2 to obtain the actual step number X_H。

8. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 7, wherein the step 7 specifically comprises:

step 7.1, selecting the phase of any one of the two frequencies for measurement

n is 1,2 denotes the nth frequency;

step 7.2, the actual phase value is obtained through the following formula (11-2)

In the formula (11-2), t is a section factor, the magnitude of which is determined by the frequency factor q, and the section factor t is 3 when q is equal to (0,0.2), 2 when q is equal to (0.2,0.3), and 1 when q is equal to (0.3, 1).

9. The two-dimensional wide-angle high-precision angle measurement method based on the eight-port four-baseline radio frequency device according to claim 8, wherein the step 8 specifically comprises: according to the actual phase value obtained in step 7

The radiation source angle theta is obtained through the formula (2-2)_H：

Images