JP2615769B2 - Direction measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an azimuth measuring apparatus, and more particularly to an A / D conversion process for a pulse radio signal required when measuring an azimuth of an incoming pulse radio wave as a measurement target. The present invention relates to a direction measuring device that improves the above.

[Prior Art] Conventionally, this type of azimuth measuring apparatus has, for example, as shown in FIG. 2, directional antennas 1a, 1b, 1c, 1d and 1e, receiving circuits 3a,
3b, 3c, 3d and 3e, A / D conversion circuits 5a, 5b, 5c, 5d and 5
e as a set, and the azimuth processing circuit 7 compares the amplitudes of the signals received by the respective directional antennas. First, an approximate azimuth is obtained from the direction of the directional antenna having the largest amplitude. For the directional antenna and the adjacent directional antenna, determine the amplitude ratio of the received signals of both, and from this amplitude ratio find the position of the incoming radio wave between the directional antennas by interpolation to obtain the correct azimuth. I have.

In this case, if the arriving radio wave is a pulse radio wave, it is necessary to quantize the amplitude of the received pulse signal by the pulse radio wave. For this purpose, the omnidirectional antenna 2 and the receiving circuit 4 connected thereto are connected. A trigger signal for amplitude quantization is generated by the trigger generation circuit 8 using this output, and is supplied to the A / D conversion circuits 5a to 5e.

[Problems to be solved by the invention]

In the above-described conventional azimuth measuring apparatus, it is necessary to perform quantization at an accurate trigger timing in order to obtain an accurate azimuth.However, when a directional antenna is arranged, a certain degree of spatial spread occurs, Furthermore, since there is a certain distance between the directional antenna and the omnidirectional antenna, there is a difference in the time at which the radio waves arrive between the directional antenna and the omnidirectional antenna, depending on the direction of the arriving radio wave. Since an error occurs in the trigger timing in the quantization, there is a drawback that it is difficult to perform the amplitude quantization with sufficient accuracy particularly in the case of an incoming radio wave having a narrow pulse width.

[Means for solving the problem]

The apparatus of the present invention comprises a plurality of directional antennas arranged in a plane at predetermined angular intervals, an omnidirectional antenna, receiving circuits respectively connected to the directional antenna and the omnidirectional antenna, and an incoming pulse. When a radio wave is received, a trigger generation circuit that generates a trigger signal from a reception signal output by a reception circuit connected to the omnidirectional antenna, and reception by the pulse radio wave respectively connected to a reception circuit connected to the directional antenna An A / D conversion circuit for reading and quantizing the signal amplitude at the timing of the trigger signal, and the directional antenna for providing the maximum reception amplitude among the quantized reception amplitudes output from each of the A / D conversion circuits. An azimuth processing circuit for obtaining and outputting the azimuth of the arriving pulse radio wave from the direction and the ratio of the reception amplitude of the adjacent directional antenna to the azimuth; Wherein the trigger generation circuit is configured as a plurality of trigger generation circuits that use the output of a reception circuit connected to the omnidirectional antenna as a common input and trigger each of the A / D conversion circuits with an output. The trigger delay time in the generation circuit is set to correspond to an arrival time difference caused by a difference in position from the omnidirectional antenna when the pulse radio wave arrives from the directional direction of the corresponding directional antenna.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings. First
The figure is a block diagram of one embodiment of the present invention. The configuration of the embodiment shown in FIG. 1 includes directional antennas 1a, 1b, 1c, 1d and 1
e, omnidirectional antenna 2, receiving circuits 3a, 3b, 3c, 3d and 3e,
4, an AD conversion circuit 5a, 5b, 5c, 5d and 5e, a trigger circuit generation circuit 6a, 6b, 6c, 6d and 6e, and an azimuth processing circuit 7; , 6b,
Elements other than 6c, 6d and 6e are the same as those shown in FIG. 2 and the detailed description of these same elements will be omitted.

In the azimuth measuring apparatus of the present embodiment, a conventional bird generates a trigger signal in a generating circuit and supplies the trigger signal to each of the AD converting circuits 5a to 5e. It comprises a plurality of trigger generating circuits 6a to 6e corresponding to the respective antennas 1a to 1e, in the case of FIG.

Furthermore, the delay time of these multiple trigger generation circuits is
Based on the directional azimuths of the corresponding directional antennas, they are set according to the delay time caused by the distance from the omnidirectional antenna 2 when a pulse radio wave arrives. In the case of FIG. 1, regarding the directional antenna 1b, the reception processing difference between the directional antenna 1 and the omnidirectional antenna 2 with respect to the direction of arrival of the pulse radio wave, that is, the delay time corresponding to the distance L is transmitted to the trigger generation circuit 6b. Will be granted. In this way, the delay time given to each directional antenna is based on the omnidirectional antenna 2 and the arrangement conditions of the directional antennas 1a to 1e, and the pulse radio waves are transmitted from the directional directions corresponding to each directional antenna. It is set in advance to correspond to the distance difference from the omnidirectional antenna when it arrives.

In this way, the difference in delay time is corrected for a directional antenna that is oriented in the direction of arrival of a radio wave or in the vicinity thereof.

Note that the delay time is not corrected for directional antennas pointing in a direction away from the direction of arrival of radio waves, but only directional antennas pointing in the direction of arrival of radio waves and their surroundings are used for azimuth measurement. Trigger timing errors occurring in distant directional antennas are not a problem.

〔The invention's effect〕

As described above, according to the present invention, a directional antenna is used instead of a single trigger generation circuit in a conventional azimuth measuring device that performs azimuth measurement using an omnidirectional antenna and a plurality of directional antennas. In addition to providing multiple trigger circuits, pulse radio waves arriving from the directional direction of each directional antenna should be quantized with a delay time corresponding to the propagation distance difference from the omnidirectional antenna. Thus, for a directional antenna that points in or near the direction of arrival of the pulse radio wave, the quantization trigger timing difference due to the radio wave arrival time difference from the non-directional antenna can be sufficiently corrected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is a block diagram of a conventional direction measuring device. 1a, 1b, 1c, 1d, 1e ... directional antenna, 2 ... directional antenna, 3a, 3b, 3c, 3d, 3e, 4 ... receiving circuit, 5a, 5b, 5c, 5d, 5e ...
... A / D conversion circuit, 6a, 6b, 6c, 6d, 6e, 7 ... azimuth processing circuit, 8 ... trigger generation circuit.

Claims (1)

(57) [Claims] 1. A plurality of directional antennas arranged in a plane at predetermined angular intervals, an omnidirectional antenna, and receiving circuits respectively connected to the directional antenna and the omnidirectional antenna.
A trigger generation circuit that generates a trigger signal from a reception signal output by a reception circuit connected to the omnidirectional antenna when an incoming pulse radio wave is received, and the pulse connected to a reception circuit connected to the directional antenna, respectively. An A / D conversion circuit for reading and quantizing the amplitude of a reception signal by radio waves at the timing of the trigger signal; and a directivity providing the largest reception amplitude among the quantized reception amplitudes output from the respective A / D conversion circuits. An azimuth processing circuit for obtaining and outputting the azimuth of the arriving pulse radio wave from the direction of the directional antenna and the ratio of the reception amplitudes of the directional antennas adjacent thereto, and outputting the azimuth. Generating a plurality of triggers that use the output of a receiving circuit connected to an antenna as a common input and trigger each of the A / D conversion circuits with an output. When configured as a circuit, the trigger delay time in each trigger generation circuit corresponds to an arrival time difference caused by a difference in position from the omnidirectional antenna when the pulse radio wave arrives from the direction of the corresponding directional antenna. An azimuth measuring device characterized in that it is set to an object.