JPS6363072B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a receiver for hyperbolic navigation, and in particular to a receiver used in the Detsuka chain of the Detsuka navigation system, which receives 8f and 8.2f signals from each station. This invention relates to a receiver for hyperbolic navigation that is capable of positioning and is inexpensive.

(b) Technical background The Detsuka system usually consists of one main station and three slave stations (red station, green station, purple station) (Detsuka chain), and the stations that form a pair of the master station and one of the slave stations emit signals. Receive each radio wave, measure the phase difference, convert the phase difference to distance, find one hyperbola with the two stations as focal points, and then Another hyperbola is obtained using the station in the same manner as above, and the position of the ship, etc. is determined from the intersection of the two hyperbolas.

The radio wave transmission schedule of the main station and the three main stations is as shown in FIG. 1, with one cycle being 20 seconds.
The transmission schedule is explained in Figure 1: 6 is the main station used for position measurement by ships, etc., 8 is the red slave station, 9 is the green slave station, and 5 is the purple slave station (fundamental frequency is approximately 14KHz)
The signal is emitted almost continuously, and during the first 10 seconds each station takes turns to identify the lane6.
Four signals 8, 9, and 5 are emitted at the same time. A conventional receiver receives these four signals and combines them within the receiver to reproduce fundamental frequency 1. If this reproduced 1 is compared in phase with the 1 generated by an oscillator synchronized with the main station signal in the receiver, this is the phase difference within the zone, and therefore lane identification can be performed. Each station also transmits an 8.2 signal, but this is for synchronization between master and slave and for aircraft receivers.
This is to obtain 0.2 from 8.2 and 8 and use it for zone identification.
It is sent for 1.75 seconds. Note that the area between adjacent position lines where the phase difference of the same wave number is 0 is called a zone.

(c) Prior Art and Problems FIG. 2 is a block diagram showing the configuration of a simple conventional deck receiver.

In the figure, 1 is the antenna, 2 is the calibration oscillator, 3-1
~3-4 are high frequency amplifiers with frequencies of 5, 6, and 6, respectively.
It is for receiving signals of 9 and 8. 4-1 to 4-4 are mixers, and 5-1 to 5-4 are first intermediate frequency amplifiers, which are amplifiers for signals having frequencies of 5F', 6F', 9F', and 8F', respectively. 6-1 to 6-3 are variable phase shifters, 7-1 to 6-3 are variable phase shifters;
7-4 is an oscillator whose oscillation frequencies are 5△, 6△,
The phases of 9△ and 8△ are each synchronized with 1△.
8-1 to 8-4 are narrowband transducers with a bandwidth of approximately 20Hz to improve signal-to-noise ratio (S/N), and the center frequencies of the passbands are 5F', 6F', 9F', and 8F', respectively. It is. Reference numerals 9-1 to 9-4 are second intermediate frequency amplifiers for signals of frequencies 5F', 6F', 9F' and 8F', respectively. Here, the frequency F' is Δ-. 10-1
~10-4 is a multiplier, 10-1 is for 5F' x 6 times,
10-2 is 10 for 6F' x 5, 6F' x 3, 6F' x 4
-3 is for 9F' x 2x, and 10-4 is for 8F' x 3x. 11 is a synthesizer, 12 is a frequency divider with a frequency division ratio of 1/6,
13 is a peak level detector, 14-1 to 14-
4 and 16 are phase difference detectors, 15-1 to 15-4 are indicators, SW is a switch, 17 is a voltage controlled oscillator (hereinafter referred to as VCO), and 18 is a low frequency generator.

Oscillation frequencies 5△, 6 of oscillators 7-1 to 7-4
△, 9△, and 8△ are the frequencies of 5F', 6F', 9F', and 8F' by passing the received frequencies of 5, 6, 9, and 8 (approximately 14KHz) through mixers 4-1 to 4-4. (F'=△-), and for example, F' is a frequency of 1KHz. In the 17 detsuka chain, as shown in Figure 1, the main station is 6, the red station is 8, and the green station is
9, the purple station emits radio waves of 5. When comparing the phase difference between the radio waves from the main station and each slave station in the Detsuka receiver, the frequencies are different, so it is impossible to compare the phases and determine the phase difference. Furthermore, in order to improve positioning accuracy, it is necessary to improve the S/N ratio.
For this reason, the Detsuka receiver transmits radio waves 5, 6, 9, and 8 emitted from each station to the antenna as shown in Figure 2.
and high frequency amplifiers 3-1 to 3-4, respectively.
and frequency-converted by mixers 4-1 to 4-4 to produce signals with frequencies of 5F', 6F', 9F', and 8F', and these signals are passed to the first intermediate frequency amplifier 5- 1-5-4
and narrowband waveforms 8-1 to 8-4.
The S/N is improved by the second intermediate frequency amplification unit 9.
The least common multiple of the 6F' signal which is amplified by -1 to 9-4 and frequency converted from 6 of the main station, and the 5F', 9F' and 8F' signals which are frequency converted from 5, 9 and 8 of each slave station. is
Multipliers 10-1 to 10 to obtain 30F′18F′, 24F′
Multiply by -4. However, the phase of the 6F' frequency of the VCO 17 is synchronized with the 6F' signal obtained by converting the frequency of the main station's signal 6 by an automatic phase control circuit consisting of a phase difference detector 16, a low frequency generator 18, and a VCO 17. The output is supplied to a multiplier 10-2 and a frequency divider 12. The multiplier 10-2 multiplies 6F' of the main station, and obtains signals of least common multiples of 30F', 18F', and 24F' for phase comparison with 5F', 9F', and 8F' of each slave station. It's becoming like that. That is, for phase comparison between the main station and the purple station, 6F' of the main station is multiplied by 5, 5F' of the purple slave station is multiplied by 6, and the phase difference is determined and displayed at 30F' via the phase difference detector 14-1. Display on the display 15-1. Similarly, for the phase comparison between the main station and the green station, 18F' is three times the 6F' of the main station and twice the green slave station, and for the phase comparison between the main station and the red station, the red slave station is four times the 6F' of the main station. The phase difference is determined by multiplying 8F by 24F' through the phase detectors 14-2 and 14-3, and displays it on the displays 15-2 and 15-3. The position is measured by the display on these indicators 15-1 to 15-3. These displays 15-1 to 15-3 indicate distances of 300m to 600m on the baseline connecting the main station and each slave station.
Display the same phase difference for each. This indicates a position within one lane and therefore:
Lane identification is required to know which lane it is in. For this reason, as shown in FIG. 1, each master and slave station synchronously emits four waves 5, 6, 8, and 9 simultaneously for a short period of time. These four waves emitted simultaneously from each station are received and frequency-converted to become signals with frequencies of 5F', 6F', 8F', and 9F'.These are added to the synthesizer 11, and the peak level is detected by the peak level detector 13. Then, as is well known, a signal with a frequency of 1F' is obtained. this frequency
The phase difference between the 1F' signal and the 1F' signal phase-synchronized with the main station signal 6 of the output of the division period 12 is determined by the phase difference detector 14-4 and displayed on the display 15-4. Lanes can be identified by the display on the display 15-4. At this time, due to the 4 waves emitted from the main station
The phase difference between the signal of 1F' and the output of the frequency divider 12 is displayed as zero on the display 15-4. However, the phase of each channel circuit from receiving the radio waves from the master and slave stations to multiplying them by the multiplier changes depending on the temperature. For this reason, it is necessary to calibrate the phase between each channel. When performing this calibration, use the switch SW.
is on the dotted line side, and the harmonics of the output of the calibration oscillator 2, which emits pulses with the same wave number equal to the fundamental frequency, are input to each high frequency amplifier 3-1 to 3-4 to create a channel for receiving the signal of 6 from the main station. The variable phase shifters 6-1 to 6-3 are adjusted so that the phase matches the standard, that is, the values on the indicators 15-1 to 15-3 become zero. It is necessary to closely match the temperature characteristics of the narrowband waveforms 9-1 to 9-4 to the extent that they can be adjusted by the variable transfer devices 6-1 to 6-3. Therefore, the receiver shown in FIG. 2 requires a receiving circuit that receives four frequencies. In addition, a calibration oscillator 2 and variable transfer devices 6-1 to 6-3 are required for calibration, and it is necessary to strictly match the temperature characteristics of the narrowband wave generators 9-1 to 9-4, and a lane identification circuit is required. It also has the disadvantage that it is necessary and expensive.

(d) Purpose of the invention In order to eliminate the above-mentioned drawbacks, the purpose of the present invention is to perform positioning by receiving signals of two waves of frequency 8 and 8.2 from each station, and to use only one reception amplification unit and lane identification. To provide a dekka receiver that does not require a calibration operation, does not require a calibration operation, can relax the temperature characteristics of a narrowband wave transmitter, and can be constructed at low cost.

(e) Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a first system in which, when a receiver receives a signal with a frequency 8 times or 8.2 times the reference frequency, the frequency is switched correspondingly. , 8F and 8.2F (F
A single-channel double superheterodyne reception amplification unit that outputs a signal with a lower reference frequency) and a VCO that tracks the phase of the 8.2F signal frequency-converted by the reception amplification unit when receiving an 8.2 signal from a slave station. Automatic phase control circuit with 8.2F of main station
The output of the VCO that tracks the phase of the signal is divided into the first
The circuit that emits the 0.2F signal of
It is characterized by being equipped with a mixer that creates a 0.2F signal for each station with the 8F signal, and a signal processing circuit that sequentially obtains the phase difference between the 0.2F signal for each station and the first 0.2F signal and calculates positioning. shall be.

(f) Embodiment of the invention An embodiment of the invention will be described below with reference to the drawings. FIG. 3 is a block diagram showing the configuration of a decker receiver according to an embodiment of the present invention.

In the figure, 1 is an antenna, 19 is a high frequency amplifier, and 2
0, 22, and 37 are mixers, 21 is a first intermediate frequency amplifier, 23 is a second intermediate frequency amplifier, 24 is a phase difference detector, 25 is a local oscillator, 26 is a synthesizer, and 27 is a frequency divider. and a multiplier, 28 a detector, 29 a timer, 30 and 31 a variable frequency divider, 3
2 is VCO, 33 to 36 are low frequency filters (hereinafter referred to as LPF)
), 38 is a frequency divider with a frequency division ratio of 1/41, 39 is a counter, 40 is a signal processor, 41 is a display, 42 is a measurement oscillator, and S1 to S5 are switches.

Figure 4 is a time chart of the signal sending times of 8 and 8.2 of the main station and slave stations and the operation of each part in Figure 3. A, B, C, and D are the main station M, the red station R, the green station G, and the purple station. The main station's radio wave transmission schedule is 8 and 8.2 in P.
8.2 is based on the time when the time synchronization signal is emitted.
E indicates the time during which the output frequency of the synthesizer is varied, and each station outputs a frequency of 8.DELTA.' during the time when it sends out a lane identification signal, and a frequency of 8.2.DELTA.' at other times. In this case, 8△′ and 8.2△′ are respectively
There is a constant phase relationship of 0.2△′. F is variable frequency divider 3
1, H indicates the output time of the 0.2F signal for each station from the mixer 37, and H indicates the measurement time for each station. The radio waves of 8 and 8.2 from each station are input to the one-channel double superheterodyne high frequency amplifier 19 via the antenna 1, amplified and input to the mixer 20, where the frequency is converted to a lower frequency and the first intermediate frequency amplifier is input. The width is increased by the width device 21 and the mixer 2
2, the frequency is converted to a lower value, amplified by the second intermediate frequency amplifier 23, and a signal having a frequency of 8F or 8.2F is output. The missers 20 and 22 receive a frequency of 8△' or 8.2, which is frequency-synthesized by a synthesizer 26 from the output of the local oscillator 25, respectively.
The signal △′ and the signal with a frequency of 8△″ or 8.2△″, which are frequency-divided and multiplied by the frequency divider/multiplier 27, are controlled by the timer 29 and are used by each station for lane identification as shown in FIG. 4E. 8△', 8 when sending a signal
At other times, signals of 8.2△' and 8.2△'' are input. For example, the frequency △′ is selected such that (△′−)=1KHz, and △″ is selected to be 1100Hz. Therefore, the first intermediate frequency amplifier 21
The frequency of the output signal of the second intermediate frequency amplifier 23 is 8KHz or 8.2KHz, and the frequency of the output signal of the second intermediate frequency amplifier 23 is 8F.
Or 8.2F becomes 800Hz or 820Hz. Therefore, the transducer of the first intermediate frequency amplifier 21 has a bandwidth of 200 Hz, and the transducer of the second intermediate frequency amplifier 23 has a narrow band width of 20 Hz, and the S/N is as follows. It is no different from the conventional one. Second intermediate frequency amplifier 23
The output is applied to the phase difference detector 24 and also to the wave detector 28, where it is detected and a DC output corresponding to the input level is obtained, which is then sent to the high frequency amplifier 19 and the first and second intermediate frequency amplifiers 21 and 23. so that the output level of the second intermediate frequency amplifier 23 remains constant.
Performs AGC control. The output of the detector 28 is added to the timer 29, and the reference time of the timer 29 is set by the synchronizing 8.2 signal transmitted for 2.5 seconds from the main station. phase difference detector 24, variable frequency divider 31,
VCO32 and LPF3 constitute an automatic phase adjustment circuit (hereinafter referred to as APC) for phase tracking of the 8.2F signal of the main station, and as shown in Figure 4F, the main station sends out the 8.2 signal for synchronization between the master and slave stations. Under the control of the hour timer 29, switch S5 is set to the dotted line side, switch S4 is connected, and the value of the variable frequency divider 31 is set so that the phase matches 8.2F, which is obtained by converting the frequency of 8.2 of the main station by the VCO 32. The value is stored in the signal processor 40, the value of the variable frequency divider 31 is kept constant, and a signal with a frequency of 0.2F obtained by dividing the output of the variable frequency divider 31 with a frequency division ratio of 1/41 is transmitted to each station. The signal is input to a counter 39 for phase comparison.

Phase difference detector 24, variable frequency divider 30, VCO3
2. LPF 33 to 34 constitute an APC for phase tracking of the 8.2F signal obtained by converting the frequency of 8.2 of the main station and each slave station. Under the control of the timer 29, the switch S5 is switched to the solid line side, and the switches S4 to S1 are sequentially connected to switch the LPFs 33 to 36, so that the phase of the VCO 32 becomes an 8.2F signal obtained by converting the frequency of 8.2 of the main station and the red, green, and purple slave stations. , each station is 8.2
The value of the variable frequency divider 30 is set as shown in FIG. 4G so that the phases match when sending signals, this value is stored in the signal processor 40, and the value of the variable frequency divider 30 for the next cycle is set. can be set in a short time, and the output of the variable frequency divider 30 is input to the mixer 37. The mixer 37 includes a second intermediate frequency amplifier 23 when sending lane identification signals for the main station and each slave station.
The 8F signal from the output of each station is input, and at that time, a 0.2F signal phase-synchronized with the 8 signals from each station is output from the mixer 37 and input to the counter 39 as shown in FIG. 4H.
This 0.2F signal is phase-compared with the 0.2F signal for phase comparison from the frequency divider 38 in the counter 39, and the clock from the measurement oscillator 42 is counted according to the phase difference and input to the signal processor 40. do. Since the clock frequency of this measurement oscillator 42 is approximately 15,000×(fundamental frequency), it is possible to obtain a resolution equivalent to that of the conventional phase comparison using 30, which has a resolution of 1/100. The signal processor 42 uses a timer 29 when each station sends a lane identification signal as shown in FIG.
Under the control of the counter 39, the data counted by the counter 39 is processed into data necessary for positioning. That is, the value of the lane identification signal of the main station is calibrated to zero.
This calibrated value is used to display the phase difference from each station on the switching display 41 when measuring each station, and the operator looks at this and determines the position of his own station. The receiver in Figure 3 uses signals with frequencies 8 and 8.2 for positioning.
Since the channel double superheterodyne receiving amplifying section is used, only one receiving amplifying section is required, and there is no need for calibration due to temperature changes, etc., and the calibration oscillator 2 and variable transfer device 6-1 shown in Fig. 1 ~6-3
is no longer necessary, and since the signals of 8 and 8.2 pass through one narrow band waver, changes in the characteristics of the narrow band waver due to temperature changes are also alleviated. Furthermore, since the frequencies of 8 and 8.2 are close to each other, compared to the conventional method, the influence of phase changes due to the influence of nighttime spatial waves is reduced and the positioning accuracy is improved. Also, the frequency is required for phase comparison.
Since a 0.2 signal (frequency-converted 0.2F) is used, the width of one lane is wider than the conventional lane identification using one signal, so a lane identification circuit is not required.

(g) Effects of the Invention As explained in detail above, according to the present invention, only one reception amplification unit is required, and there is no need for a calibration circuit or lane identification circuit due to temperature changes, and characteristic changes due to temperature changes of the narrowband waveform generator are eliminated. This has the effect of relaxing the standards, making it possible to obtain inexpensive receivers, reducing the influence of spatial waves, and improving positioning accuracy.

[Brief explanation of drawings]

Figure 1 is a radio wave transmission schedule diagram of a deck chain, Figure 2 is a block diagram showing the configuration of a conventional simple deck receiver, and Figure 3 is a block diagram showing the configuration of a deck receiver according to an embodiment of the present invention. Figure 4 shows the transmission time of signals 8 and 8.2 of each station and the third
A time chart of the operation of each part in the figure is shown. In the figure, 1 is the antenna, 2 is the calibration oscillator, 3-1
~3-4, 19 is a high frequency amplifier, 4-1~4-
4, 20, 22, 37 are mixers, 5-1 to 5-
4, 9-1 to 9-4, 21, 23 are intermediate frequency amplifiers, 6-1 to 6-3 are variable transfer devices, 7-1 to 7-
4, 25, 42 are oscillators, 8-1 to 8-4 are narrowband wave generators, 10-1 to 10-4 are multipliers, 11 is a combiner, 12 and 38 are frequency dividers, 13 is a peak level detector 14-1 to 14-4, 16, 24 are phase difference detectors, 17, 32 are voltage controlled oscillators, 1
8, 33 to 36 are low frequency devices, 15-1 to 15-
4, 41 is a display, 26 is a synthesizer, 27 is a frequency divider, 28 is a detector, 29 is a timer, 3
0 and 31 are variable frequency dividers, 39 is a counter, 40 is a signal processor, and S1 to S5 and SW are switches.

Claims (1)

[Claims] 1 In a hyperbolic navigation receiver, when receiving a signal with a frequency 8 times or 8.2 times the reference frequency, the frequency is changed in two stages according to the frequency of the first and second local oscillators, which change the frequency accordingly. A 1-channel double superheterodyne receiver amplification unit that outputs signals whose output frequencies are 8 times and 8.2 times the lower reference frequency F, whose frequencies are lowered and brought closer to each other so as to pass through one narrow band waver. , and an automatic phase control circuit with a voltage controlled oscillator that tracks the phase with the 8.2F signal frequency-converted in the reception amplification section when receiving the 8.2 signal from the main station and slave station, and tracks the phase of the 8.2F signal from the main station. A circuit that divides the output of the voltage controlled oscillator and generates the first 0.2F signal, and the output of the voltage controlled oscillator that tracks the phase of the 8.2F signal for each station, and when each station emits radio waves for lane identification. , a mixer that creates a 0.2F signal for each station with the 8F signal output from the reception amplification section, and a signal that sequentially determines the phase difference between the 0.2F signal for each station and the first 0.2F signal and calculates positioning. A hyperbolic navigation receiver characterized by comprising a processing circuit.