JP3480804B2 - Orientation measuring device and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an antenna that captures an incoming electromagnetic wave by rotating or scanning a beam having directivity, and captures the incoming electromagnetic wave to measure the incoming direction of the electromagnetic wave. The present invention relates to a measuring device and method.

[0002]

2. Description of the Related Art Generally, in an azimuth measuring apparatus using an antenna for capturing an incoming electromagnetic wave by rotating a beam having directivity, the direction of a rotating beam is gentle when the waveform is low. It becomes a waveform and becomes sharp at a high frequency. Here, respective schematic waveforms when the rotating beam makes one rotation are shown in FIGS. 5 and 6. 5 and 6, the vertical axis represents the signal level, that is, the intensity of the electromagnetic wave, and the horizontal axis represents the azimuth of the rotating beam. Further, FIG. 5 shows the case where the frequency is low, and FIG. 6 shows the case where the frequency is high.

In the waveforms of FIGS. 5 and 6, the arrival direction of the electromagnetic wave is the direction in which the electromagnetic wave is most strongly received, that is, the direction in which the waveform has the maximum peak. Here, one method for automatically reading the azimuth is to perform peak search processing of the waveform and determine the arrival azimuth based on the search result. When the input waveform has a high frequency, the peak can be easily determined as shown in FIG. 6, but as the frequency becomes lower, the peak portion becomes gentle as shown in FIG. Therefore, the azimuth cannot be determined, or even if it can be determined, the determined azimuth includes a large error.

Furthermore, when an actual electromagnetic wave is received, noise is superimposed on the waveform output as the search waveform, and it becomes more difficult to determine the direction. As another method for automatically reading the azimuth, there is a method of determining the arrival azimuth by performing a correlation process on the search waveform. Waveforms obtained by this correlation processing are shown in FIGS. Figure 7 shows the waveform when the frequency is low,
FIG. 8 shows a waveform when the frequency is high. Further, in FIGS. 7 and 8, the vertical axis represents the signal level and the horizontal axis represents the azimuth of the rotating beam.

That is, in the method based on this correlation processing, a reference pattern of a waveform is prepared, a correlation value between this reference pattern and an input search waveform is extracted, and the peak portion of this correlation value reaches an electromagnetic wave. It is obtained as an azimuth.

However, the above-mentioned correlation processing also has the same problem as the above-mentioned peak search processing, and when the direction search waveform is a gentle waveform, the result of the correlation processing is also gentle as shown in FIG. It is difficult to determine the peak.

[0007]

As described above, in both the peak search processing and the correlation processing, when the input search waveform is gentle, the arrival of the electromagnetic wave captured by the antenna Not only is it difficult to determine the azimuth, but there is a problem that the measurement result of the determined arrival azimuth contains a large error.

An object of the present invention is to provide an azimuth measuring apparatus and method capable of accurately measuring the azimuth of arrival of an electromagnetic wave captured by an antenna even in the case of a gentle search waveform.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention focuses on providing an antenna for capturing an incoming electromagnetic wave by rotating or scanning a beam having directivity. Is obtained using
After converting the beam waveform including the capture result of the electromagnetic wave into the reception frequency specified for the reception processing, the direction waveform showing the maximum amplitude in the arrival direction of the electromagnetic wave is formed. Then, with respect to this direction-finding waveform, a waveform change component per unit time is extracted and combined with the reference waveform showing the maximum amplitude in the beam transmission initial direction of the antenna obtained in advance as a reference, and The impulse response waveform showing the maximum peak value is shaped, and the arrival direction of the electromagnetic wave is calculated based on this impulse response waveform.

Specifically, in addition to the above antenna, a receiving section for converting a beam waveform obtained by this antenna and including a capture result into a reception frequency specified for reception processing,
Based on the output of this receiving unit, it is determined in advance for the direction-search waveform shaping unit that shapes the direction-search waveform showing the maximum amplitude in the arrival direction of the electromagnetic wave and the direction-search waveform formed by this direction-search waveform shaping unit. Based on the reference waveform showing the maximum amplitude in the initial beam transmission direction of the antenna, by extracting and combining the waveform change components per unit time, the impulse response waveform showing the maximum peak value in the arrival direction of the electromagnetic wave is formed, A signal waveform processing unit that calculates the arrival direction of the electromagnetic wave based on the impulse response waveform is provided.

According to this structure, an incoming electromagnetic wave is captured by using an antenna that rotates or scans a beam having directivity, and a beam waveform including the captured result is input to show the maximum amplitude in the incoming direction of the electromagnetic wave. Shape the direction search waveform, and extract the waveform change component per unit time with reference to the reference waveform that has the same frequency as the direction search waveform shown in the initial direction of beam transmission of the antenna for this direction search waveform. By combining them, a sharp peak is formed in the arrival direction of the electromagnetic wave, and the impulse response waveform is formed without the appearance of the peak in the direction other than the electromagnetic wave. In this case, the impulse response waveform is obtained by performing a deconvolution process corresponding to the inverse calculation of the convolution calculation on the search waveform and the reference waveform.

As a result, the obtained impulse response waveform has a sharp peak in the incoming azimuth of the electromagnetic wave even when the input waveform is gentle at a low frequency, so that the azimuth can be easily determined and the azimuth determination error can be eliminated. It is possible to accurately measure the arrival direction of electromagnetic waves.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a block configuration of an azimuth measuring apparatus according to an embodiment of the present invention, and FIG. 2 shows an antenna pattern for capturing an electromagnetic wave coming from a single direction, for example.

In FIG. 1, reference numeral 11 is an antenna, which transmits an antenna beam A having directivity and rotates or scans this antenna beam A in the direction of arrow Z1 shown in FIG. (For example, azimuth −45 ° in FIG. 2) is captured. Then, the antenna beam waveform signal obtained by the antenna 11 and including the electromagnetic wave capture result is supplied to the receiving unit 12. Note that FIG. 2 shows an example in which the antenna beam A is rotated.

The receiving unit 12 converts the input antenna beam waveform signal into an intermediate frequency signal specified for reception processing and outputs the intermediate frequency signal to the direction search waveform shaping unit 13. The direction search waveform shaping unit 13 shapes a direction search waveform having the maximum amplitude in the arrival direction of the electromagnetic wave based on the input intermediate frequency signal, and outputs the direction search waveform signal to the signal waveform processing unit 14.

The signal waveform processing unit 14 stores in advance a reference waveform having the maximum amplitude in the antenna beam transmission initial azimuth of the antenna 11 and having the same frequency as the direction finding waveform. , The waveform change component per unit time is extracted based on the reference waveform and combined to form an impulse response waveform that shows the maximum peak value in the arrival direction of the electromagnetic wave. Based on this impulse response waveform, the arrival of the electromagnetic wave The azimuth is measured, and the measurement result is output to an external device (not shown).

Next, the processing operation of the signal waveform processing section 14 will be described with reference to FIGS. 3 and 4. 3 and 4, the vertical axis represents the signal level, that is, the strength of the electromagnetic wave, and the horizontal axis represents the azimuth.

That is, as shown in FIG. 3, the search waveform input to the signal waveform processing section 14 is a reference waveform showing the maximum amplitude in the antenna beam transmission initial direction of the antenna 11,
It is assumed that it is generated by convolution with an impulse response waveform indicating the direction of the electromagnetic wave, that is, convolution calculation processing.

Therefore, the signal waveform processing section 14 is configured as shown in FIG.
As shown in FIG. 5, a defocusing process corresponding to the inverse calculation of the convolution calculation is performed by inputting the direction search waveform and giving the reference waveform showing the maximum amplitude in the antenna beam transmission initial direction (direction of 0 ° in FIG. 4). By executing, the impulse response waveform showing the maximum peak value in the arrival direction of the electromagnetic wave is obtained. That is, the deconvolution process is a process of extracting and combining waveform change components per unit time with respect to the search waveform with reference to the reference waveform.

The position of the impulse in this impulse response waveform indicates the time position (t) of the search waveform. Here, the arrival direction θ of the electromagnetic wave is expressed by the following equation, where t is the time position of the impulse and T is the time of one cycle of the waveform. θ = (t / T) × 2π [rad] Here, the obtained impulse is the conventional peak search,
Unlike the gentle waveform obtained as a result of the correlation processing or the like, it has a sharp peak even when the input waveform is gentle.

Therefore, according to the above embodiment, the antenna 11 for rotating or scanning a beam having directivity.
After the incoming electromagnetic wave is captured by using, the antenna beam waveform including the captured result is converted into an intermediate frequency signal by the receiving unit 12, and then the radial search waveform shaping unit 13 displays the maximum amplitude at the incoming position of the electromagnetic wave. A waveform is formed, and the signal waveform processing unit 14
The deconvolution process corresponding to the inverse calculation of the convolution calculation is performed by giving a reference waveform having the same frequency as the search waveform shown at the beam transmission initial position of the antenna 11 obtained in advance to the search waveform. As a result, a sharp peak is formed at the arrival position of the electromagnetic wave, and the impulse response waveform is formed without the appearance of the peak at the position other than the electromagnetic wave.

For this reason, the obtained impulse response waveform has a sharp peak at the arrival position of the electromagnetic wave even when the input waveform is gentle at a low frequency, so that the azimuth determination is easy and the azimuth determination error is eliminated. It is possible to accurately measure the arrival direction of electromagnetic waves. Furthermore, it is possible to remove noise and the like superimposed on the direction search waveform.

Further, according to the above-described embodiment, the beam waveform including the electromagnetic wave obtained by rotating the single beam by the antenna 11 is converted into the direction search waveform, and then the signal waveform processing unit 14 is used as a reference. Since it is possible to obtain an impulse response waveform only by giving a waveform and executing deconvolution processing, complicated waveform processing is not required, and this enables high-speed processing of the waveform and downsizing of the device. Can contribute.

Further, in the above embodiment, the maximum peak value of the impulse response waveform is normalized to 1, and this impulse response waveform is raised to the power of n (n is an integer) to obtain a good impulse response waveform. Good.

In the above embodiment, it goes without saying that the shape of the antenna 11, the method for forming the antenna beam, and the method for generating the radial search waveform in the radial search waveform shaping section 13 may be any method. is there. Further, it is needless to say that the present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the scope of the invention.

[0026]

As described above in detail, according to the present invention,
It is possible to provide an azimuth measuring device and method capable of accurately measuring the arrival azimuth of an electromagnetic wave captured by an antenna.

[Brief description of drawings]

FIG. 1 is a block configuration diagram showing an embodiment of an azimuth measuring device according to the present invention.

FIG. 2 is a view showing an antenna pattern for capturing electromagnetic waves coming from a single direction in the same embodiment.

FIG. 3 is a diagram for explaining convolution processing as an example of a processing operation of a signal waveform processing unit in the same embodiment.

FIG. 4 is a diagram shown for explaining deconvolution processing as an example of a processing operation of a signal waveform processing unit in the same embodiment.

FIG. 5 is a diagram showing an example of a low-frequency waveform obtained by conventional peak search processing.

FIG. 6 is a diagram showing an example of a high frequency waveform obtained by conventional peak search processing.

FIG. 7 is a diagram showing an example of a low-frequency waveform obtained by conventional correlation processing.

FIG. 8 is a diagram showing an example of a high-frequency waveform obtained by conventional correlation processing.

[Explanation of symbols]

11 ... antenna, 12 ... Receiver 13 ... Directional waveform shaping section, 14 ... Signal waveform processing unit.

Claims (4)

(57) [Claims] 1. An antenna for capturing an incoming electromagnetic wave by rotating or scanning a beam having directivity, and a beam waveform including the capture result obtained by this antenna at a reception frequency specified for reception processing. A receiving unit for converting, a direction-finding waveform shaping unit for shaping a direction-finding waveform showing the maximum amplitude in the arrival direction of the electromagnetic wave based on the output of the receiving unit, and a direction-finding waveform shaped by the direction-finding waveform shaping unit. On the other hand, with reference to the reference waveform having the same frequency as the direction waveform and showing the maximum amplitude in the beam transmission initial direction of the antenna obtained in advance, by extracting and combining the waveform change components per unit time, The impulse response waveform showing the maximum peak value in the arrival direction of the electromagnetic wave is shaped, and the arrival direction of the electromagnetic wave is calculated based on the impulse response waveform. An azimuth measuring apparatus comprising: a signal waveform processing unit. 2. The signal waveform processing section executes deconvolution processing, which corresponds to an inverse operation of a convolution operation, on the direction search waveform and the reference waveform,
The azimuth measuring apparatus according to claim 1, further comprising deconvolution processing means for obtaining the impulse response waveform. 3. A beam waveform obtained by this antenna, which is obtained by this antenna when the incoming electromagnetic wave is captured by rotating or scanning a beam having directivity, and is specified for reception processing. After converting to the reception frequency, a direction finding waveform showing the maximum amplitude in the arrival direction of the electromagnetic wave is shaped, and the direction finding waveform showing the maximum amplitude in the initial direction of the beam transmission of the antenna is obtained for the direction finding waveform. With a reference waveform having the same frequency as the waveform as a reference, by extracting and combining waveform change components per unit time, an impulse response waveform showing the maximum peak value in the arrival direction of the electromagnetic wave is formed, and this impulse response waveform is formed. The azimuth measuring method is characterized in that the arrival azimuth of the electromagnetic wave is calculated based on the azimuth. 4. The azimuth according to claim 3, wherein the impulse response waveform is obtained by executing a deconvolution process corresponding to an inverse operation of a convolution operation of the square wave waveform and the reference waveform. Measuring method.