JPS582764A - Direction finding system using hyperbolic navigation - Google Patents

Abstract

PURPOSE:To measure the direction of a local ship with a comparatively simple constitution, by using a hyperbolic navigation receiver which measures the position presently the ship is navigating. CONSTITUTION:Loran signals received by antennas 1 and 2 which are set in positions different by a specified range D on the bow line are led to gate circuits 5 and 6, and the loran signal received by the antenna 1 is led to a loran receiver 7 to perform the normal loran navigation. A pair of phase difference data measured by the receiver 7 is sent to a latitude and longitude operating circuit 9, and the latitude and the longitude are operated in the circuit 9 on a basis of data of the transmitting station position from a storage circuit 10 and are displayed on a position display part 11 and are sent to a direction operating circuit 12 also. Gate signals generated in the receiver 7 pass through gate circuits 5 and 6 and are compared with each other in phase by a phase comparing circuit 14 simultaneously with the appearance of a station signal designated by a measuring station setting equipment 13, and arrangement directions of antennas 1 and 2 are operated in a direction operating circuit 12 and are displayed on a direction display part 15.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to measure the heading of a ship using a hyperbolic navigation receiver.

The direction of the own ship is generally measured using a magnetic compass or a gyro compass. This type of device is relatively expensive, and the installation location must be selected to have as few error factors as possible. Furthermore, it is relatively difficult to process the measured orientation as an electrical signal.

This invention utilizes hyperbolic navigation to measure navigational positions, e.g.
Using a navigation receiver that performs Loran navigation, Detsuka navigation, Omega navigation, etc., the ship's direction is measured with a relatively simple configuration.

An embodiment in which the present invention is carried out using Loran navigation will be described below.

In FIG. 1, reference numerals 1 and 2 are receiving antennas for Loran signals, which are set, for example, at different positions on the bow line by a certain distance.

The Loran signal received by each of the receiving antennas 1.2 is amplified by a respective preamplifier 3.4 and then connected to one transmission line t1.
- Guided to each gate circuit 5.6 via t2.

On the other hand, the nine loran signals received by the receiving antenna 1 are guided to the loran receiver 7, where normal loran navigation is performed. That is, the Loran receiver 7 selects the desired transmitting station chain selected by the chain selector 8, for example, one main transmitting station and two reverse transmitting stations in Loran C navigation, and selects the desired transmitting station chain selected by the chain selector 8, for example, one main transmitting station and two reverse transmitting stations, and The phase difference between each slave signal is measured in a known manner.

A pair of phase difference data measured by the Loran receiver 7 is sent to the latitude/longitude calculation circuit 9. The latitude and longitude calculation circuit 9 calculates the latitude and longitude of the point where the phase difference measurement was performed, and serves as a transmitting station position storage circuit.

The above latitude and longitude calculations are performed based on the transmitting station position data sent from 10. In addition, the transmitting station position storage circuit I
O stores position data of each transmitting station in advance, and the position data of the transmitting station chain selected by the chain selector 8 from among the stored data is sent to the latitude/longitude calculation circuit 9.

The above latitude and longitude calculations can be performed in a known manner. That is, since the phase difference measured by the Loran receiver 7 is expressed as a position on a hyperbola where the distance difference from the pair of transmitting stations is constant, the hyperbola corresponding to the pair of phase difference data sent from the Loran receiver 7 Calculate the latitude and longitude corresponding to the intersection.

The calculation results of the latitude and longitude calculation circuit 9 are sent to the position display 11 for display, and are also sent to the azimuth calculation circuit 12 at the same time. The orientation calculation circuit 12 calculates the arrangement orientation of the receiving antennas 1 and 2, and this will be explained below.

Gate circuits 5 and 6 allow only the Loran signal of a specific station to pass among the Loran signals of each station arriving at each receiving antenna 1.2. This signal selection is performed by the measurement station setter 13. The measurement station setter 13 specifies one of the transmitting stations from the transmitting station chain on which the rosin receiver 7 performs phase difference measurement.

When performing phase difference measurements, the Loran receiver is designed to perform station identification of the Loran signal.

For example, in Loran C navigation, the time relationship between the main station signal and each slave station signal is fixed in advance, and by receiving the Loran signal having this time relationship, the master station and slave station Loran signals can be identified. Can be done. and,
After each station signal is identified, the gate wave generated in the Loran receiver 7 is sent to the gate circuit 5.6 to establish continuity between its input and output, coinciding with the appearance of the station signal specified by the measurement station setter 13. . As a result, only the station signal designated by the measuring station setter 13 passes through the gate circuit 5.6 and is guided to the phase comparator 14.

The phase comparator 14 measures the phase difference between the Loran signals of the same station derived from the gate circuit 5.6. This phase difference is caused by the spacing between the receiving antennas 1 and 2. In Fig. 2, when measuring the phase difference of the Loran signal transmitted from position ftQ by placing receiving antennas 1.2 at positions At and A2, the distance R to the receiving point is
．． 2, the equiphase wavefront of the transmitted signal is represented by a straight line W perpendicular to the straight line connecting the transmitting point Q and the receiving point A1. Therefore, the phase difference θ measured by the phase comparator 14 changes in proportion to the distance difference d between the receiving points A1 and A2 in the direction of the transmitting station, and is expressed as d=, -, a.

However, A indicates the wavelength.

Therefore, the relative orientation of the receiving points A1 and A2 with respect to the direction of the transmitting station, that is, the relative orientation α in which the receiving antenna 1.2 is arranged can be known from 1d2.

The measured phase difference θ of the phase comparator 14 is sent to the azimuth calculation circuit 12, where the orientation of the receiving antenna 1.2 is calculated.

The azimuth calculation circuit 12 first uses the above phase difference - to calculate
The relative orientation α is calculated by calculating the equation 0. On the other hand, the transmitting station direction β is calculated based on the latitude and light data of the receiving point A1 sent from the latitude and longitude calculating circuit 9 and the latitude and longitude of the transmitting point 1tQ. Calculate direction.

The result of this calculation is then sent to the direction display 15 and displayed.

In the above, the latitude and longitude data of the transmitting station position Q are derived from the transmitting station position memory circuit 10, and the latitude and longitude data of the master station and slave station are derived from the transmitting station position memory circuit 10 to the latitude and longitude calculation circuit 9. Among the data, the latitude and longitude data of the station specified by the measurement station setter 13 is sent from the selection circuit 16 to the azimuth calculation circuit 12. Further, the phase difference output of the phase comparator 140 is adjusted by a phase adjuster 17. This is the receiving antenna 1.2
The Loran signal that reached +1 is sent to preamplifier 3.4, transmission line 4, and t2.
The phase comparator 14 calibrates the amount of phase shift caused by the phase comparator 14.
Adjustments are made in advance so that the measured phase difference is zero.

In Fig. 2, the relative azimuth α of the receiving points A1 and A2, which corresponds to the distance difference d1 in the direction of the transmitting station between the receiving points A + and A2, that is, the phase difference θ of the received signals of the receiving points A1 and A2, is symmetrical to a straight line. The same is true for direction -a.

The phase difference is measured, resulting in an unambiguous orientation. When the relative orientation a is close to 900, the uncertain orientations are substantially opposite to each other, and therefore can be identified relatively easily. or,
As is clear from the equations (2) and 0 above, the rate of change of the relative azimuth α with respect to the measured phase difference θ is the smallest when the relative azimuth α is in the 900 direction, and increases as the relative azimuth α becomes smaller. Therefore, the relative orientation α of receiving points AI and A2 is 90'
The error is smallest when the direction is in the direction, and the above-mentioned unclear direction can be easily identified. Therefore, it is desirable that the transmitting station set by the measurement station setter 13 be such that the relative azimuth α is as close to 900 as possible.

FIG. 3 shows an embodiment in which, based on the above, the relative relative azimuths α for a plurality of transmitting stations are each measured separately, and the relative azimuth closest to 90' is automatically selected from among them. Items with the same numbers as in the figure perform the same operations.

In FIG. 3, phase comparators 14A, 14B, 14
0 performs a phase difference measurement of a different transmitting station signal.

For example, phase comparator 14A measures the phase difference between the main station signals arriving at receiving antenna 1.2. This main station signal is selected by the gate circuits 5A and 6A based on the gate signal generated in the Loran receiver 7 when the main station signal arrives. Further, the phase comparator 14B operates to control the gate circuit 5B,
Measure the phase difference of the slave signal sent from 6B. Similarly, phase comparator 140 measures the phase difference between other slave signals sent from gate circuits 50 and 60.

The measured phase differences of each of phase comparators 14A, 14B, 140 are directed to comparator circuit 18. The comparator circuit 18 selects, from among these phase differences, the phase difference in which the relative orientation α is closest to 90°, that is, the one with the smallest phase difference, and sends it to the orientation calculation circuit 12'. Further, the comparator circuit 18 sends the selected station data to the selection circuit 16', and causes the selection circuit 16' to send the position data of the station to the azimuth calculation circuit 12'.

The azimuth calculation circuit 12° performs azimuth calculation in the same manner as in FIG. Also, at this time, the phase comparators 14A, 14B14
Using the measurement data of 0, identification of the uncertain direction of the relative direction α is also performed at the same time.

As explained above, according to the present invention, it is possible to measure the own ship's bearing with relatively high accuracy using hyperbolic navigation signals, and since the measured bearing can be easily extracted as an electrical signal, the bearing It is also possible to apply the data to ship maneuvering equipment.

*Although the above embodiment has been described using Loran navigation, it is also possible to implement it in the same way using Detsuka navigation or Omega navigation. In other words, in the case of Detsuka navigation,
As shown in FIG. 1, receivers for each frequency may be used in place of the single circuit 5.6. Further, the computation of the azimuth angle and other data processing in the above embodiment can easily be performed in a process manner using a microcombinator. The figure is a diagram for explaining the operation, and FIG. 3 shows another embodiment.

Applicant: Furuno Electric Co., Ltd. 1st eye one: , +2. eye

Claims (2)

[Claims] (1) In hyperbolic navigation, which measures the arrival time difference (phase difference) of navigation signals transmitted from each of a pair of transmitting stations to determine the own ship's position, a pair of receiving antennas placed at different positions on the ship; Based on the time difference (phase difference) in which a navigation signal from one of the transmitting stations reaches the pair of receiving antennas, the relative positioning direction of the pair of receiving antennas and the transmitting station that measured the time difference (phase difference). means for measuring the azimuth, and calculating the arrangement azimuth of the pair of antennas based on the measured relative azimuth, the transmitting station position where the relative azimuth was measured, and the own ship position measured using the hyperbolic navigation. A direction measurement method using hyperbolic navigation comprising: (2) In hyperbolic navigation, which measures the arrival time difference (phase difference) of navigation signals transmitted from each of a pair of transmitting stations to determine the ship's position, a pair of receiving antennas placed at different positions on the ship; Based on the time difference (phase difference) in which a navigation signal from one of the transmitting stations reaches the pair of receiving antennas, the relative positioning direction of the pair of receiving antennas and the transmitting station where the time difference (phase difference) was measured. A first relative azimuth measuring means for measuring the azimuth, and a time difference (phase difference) between the navigation signals of another transmitting station different from the transmitting station measured by the first relative azimuth measuring means reaching the pair of receiving antennas. a second relative azimuth measuring means for measuring the relative azimuth in which the pair of antennas are arranged relative to the transmitting station where the time difference (phase difference) was measured; means for comparing the respective relative azimuths with each other and selecting a relative azimuth with a relative azimuth angle closer to 90°, the selected relative azimuth, a lid with a transmitting station that measures the selected relative azimuth, and the hyperbola. An azimuth measurement method using hyperbolic navigation, comprising means for calculating the arrangement azimuth of the pair of receiving antennas based on the ship's own position measured using navigation.