RU7211U1 - SIGNAL DELAY MEASUREMENT DEVICE - Google Patents

Abstract

A device for measuring the delay of a radiated signal or an echo signal in acoustic, hydroacoustic navigation, location or sounding systems, comprising a processing unit connected to the output of a half-wave detector, as well as to a control input of a master oscillator, the output of which is connected to a transceiver complex consisting of a signal synthesizer, the input of which connected to the output of the master oscillator, the transmitter, the output of which is connected to the transmitting (or combined transceiver) antenna, the receiver, connected Go to the receiving (or transceiving) antenna, characterized in that the device is made in the form of several transceiving complexes operating at different frequencies, moreover, a delay circuit is included between each synthesizer and transmitter, and a phase correction circuit is introduced in the receiver, in addition, the outputs of the receivers of each complex are connected to a multi-input amplitude adder, the output of which is connected to the first input of the correlator, the second input of which is connected to the master oscillator, and the third input is connected to the output By the code register register of the pseudo-random sequence, the correlator output is connected to the input of a half-wave detector, and the code register output is also connected to the synthesizers of each complex.

Description

SIGNAL SIGNAL MEASURING DEVICE

The utility model relates to navigation or location (probing) means, mainly in acoustic, hydroacoustic or seismic acoustic systems that measure the distance between transmitting and receiving objects or the distance to reflecting objects.

At the current level of technology, great importance is attached to the accuracy of determination and resolution of objects in range. Improving accuracy and resolution allows you to get a more detailed picture of the reflecting formations in the distribution medium.

Moreover, the sharper the pulse and the shorter the time, the better resolution can be achieved.

In addition to resolution, the most important characteristic is also the maximum achievable range of the device, which is determined by 12; p.141 by the energy of the Ni of the emitted signal, where Pu is the power in the pulse, and Ti is the pulse duration.

It can be seen from the formula that signals with a short Ti duration have the disadvantage of the impossibility of obtaining high energy of the useful signal and, therefore, are significantly limited in the range of the device, since an increase in the duration worsens the resolution, and an increase in the Pu power always encounters technical limitations.

m /; iff9

IPC G 01 S 15/00

G P tg p-g-rj f t t ti G t PT

The known device 1: pp. 20-211, taken as a prototype, contains a stable reference master oscillator (see Fig. 1), launched from the processing unit, the signal of which is transmitted to the transceiver complex to the frequency synthesizer and the duration of the emitted signal. can be compressed to the duration of a single short initial pulse. Thus, an increase in range can be achieved while maintaining the same resolution as when emitting a single short pulse. Known 2; p. 141 intrapulse linear frequency modulation and extratrimp1 simple 51 Phase shift keying. However, the spectrum of modulated signals with these types of modulation is almost continuous and occupies a bolush band. Thus, chirp profilographs with a linear frequency bandwidth of several octaves and even up to 5 decades 3 are used to probe mopey bottom sediments: page 12. The creation of such ultra-wide-band emitting antennas presents extremely great difficulties, since the best antennas of ordinary use have a broadband not exceeding one octave C4: p. 40. The proposed device solves the following problems: -saving high-resolution range, inherent in short single pulses: -increasing the signal energy and. consequently, an increase in the validity of the action of the property due to the additional coding of the emitted signal by a pseudo-random sequence; -use of antennas for use with octave - 2 From the synthesizer, the signal is transmitted to the transmitter-shk, then to the transmitting (or combined transmitting transmitting) antenna. After propagation in the medium or after reflection from objects, the signal enters the receiver (or transmit-receive) antenna and then to the receiver. From the output of the receiver, the signal through a half-wave detector enters the processing unit.

The disadvantage of the prototype is the low energy of the useful signal, since it is limited by the short duration of this signal.

The essence of the proposed device is that to increase the range, short pulses are emitted simultaneously at different frequencies by a series, repeating in a series repeatedly with a change in polarity according to the law of a pseudorandom sequence, for example, according to Barker iodine 5: p. 41 1. followed by correlation processing (compression) the sequence and obtaining a correlator of the initial short signal with a sharp maximum. but with the energy increased in w squared 2 times; p. 20, where w is the number of pulses in one pseudo-random sequence. For Barker codes, w cannot be more than 13 5, for M-sequences and Legendre sequences, the number of w pulses can be from several tens to several thousand, which can be squared times after correlation processing of the energies of the useful signal, and, therefore, significantly Increase device performance. I

In this case, it can make up a decade or more if we compare the lowest and highest frequencies in the spectrum of the total signal. Thus, it is possible to overcome the difficulties of the practical implementation of ultra-wideband antennas.

To achieve the above results, the utility model contains, as in the prototype, a stable reference oscillator 1 (see Fig. 2), synchronizing the operation of several receiving and transmitting complexes and starting from the processing unit 2. The functions of the processing unit 2 include control of the entire device, as well as preparing and displaying processed information in a convenient form for perception.

The master oscillator 1 provides a stable reference signal to the synthesizers 3 of each transceiver complex. In addition, the master oscillator 1 generates clock parcels for the correlator 4 to synchronize its operation with other nodes of the device.

Synthesizers 3 generate the frequency and duration of the short signals from the reference signal of the master oscillator 1, and also form a pseudo-random sequence of these short signals based on the code of the pseudo-random sequence recorded in register 5.

Next, the signals of synthesizers 3 are fed to delay circuits 6, with the help of which delays are set when setting up the equipment, chosen in such a way as to phase out the moments of the maximum values of the signals of all complexes.

From delay circuits 6, the signals are transmitted to the transmitters, then to the transmitting (or combined receiving-transmitting) antennas 8. After propagation in the medium or after reflection from objects, the signals are transmitted to the receiving (or receiving-transmitting 4 transmitting) antennas 9, and then to the receivers 10. where it is additionally corrected in phase in phase correction schemes 11 for exceptions of phase outs of signals in receiving paths so as to combine in time the maximum values of the signals of all transceiver complexes before the car: the signals will arrive at the amplitude adder 12. After summing in the multi-input amplitude adder 12, the signal has a sharper and higher maximum than at the output of any of the transceiver complexes, which contributes to achieving good resolution in range and some gain in signal energy, i.e. increase the range of the device. From the output of adder 12, the signal enters the correlator 4, where the operation of determining the autocorrelation function H (t-Tz) between the signal from the adder 12 and the reference pseudorandom sequence from code register 5 is performed. The autocorrelation function Pccc-cz) is determined by expression 2; НСС-з) -1 / Тн J U (). U (t-C) dt, where О U (t-ti) is the signal from the output of the adder 12; U (t-t) is the signal corresponding to the reference pseudo-random sequence from code register 5; Tn is the observation time, i.e., the duration of the reference sequence. h / w -larity, the value of RCC-t) reaches the maximum, since the shape of the received signal and the sequence are the same. At the same time, at the output of the correlator 4, a short sharp pulse will appear in duration and shape close to a single pulse at the output of the adder 12, but its amplitude is times and times larger. Thus, the energy of the output pulse of the correlator 4 increases in w squared times, which helps to increase the range of the device while maintaining a range resolution comparable to the prototype. The operation of calculating the autocomponent R (t-1 :,) in the correlator 4 can be performed either in analog form using the delay line with taps Г2; strL8 in the circuit of the received signal or with a plural delay line in C € pi reference pseudorandom and randomness 2, p. 28. It is also possible to calculate the autocorrelation function using a digital representation of the received signal and a digital representation of the pseudo-random sequence. All of these options are ultimately described by the above formula. From the output of the correlator 4, the signal is fed to a half-wave detector 13, where the sharp maximum of the useful signal is emitted, and the opposite polarity, which does not have a sharp maximum, is not irregular. Further, the Iplezin sipsl enters the processing unit 2, where the processing and output of the received and processed information to registracin is carried out. in a convenient d; w perceptible form. a 1.-.-.

In Fig. 3 shows the three-frequency version of the proposed device, using at each frequency signals with a maximum resolution of 4; p. 23. those. having a duration of about one frequency period and a quasi-sinusoidal shape. 1IRind STRIP TyKykh SI. : 1ll:. ;; ;; I. prcEashazt of one octave 4; p. Fig.Z demonstrates the ability to receive in the proposed device osgpnh pulses of high resolution in the range and and, the primary amplitude of the total signal. On Fig.3 also shows the signal of the prototype (Eparius B) under the assumption that the frequency of the signal of the prototype is equal to the frequency of the highest frequency (third) transceiver complex of the proposed device.

Psyura and (Fig. C) signal of the first transceiver complex (PPC) after delay circuit 6 (see Fig. 2). The proposed device shows only one first pulse. The entire pseudo-random sequence is shown in FIG. Diagram O - cwiiid BP: ,,,,: :: nocj; :: x8MS delay b

(see FIG. 2) „

Diagram B is the signal of the third IRC after the delay circuit 6 (see Fig. 2) .3 diagram B also corresponds to the output signal .riHKa of the prototype ..

Zpyura G - signals i; 2; 3 i.v.j .; ; p: 1smiikov iO (see figure 2) of three PPC; signal 4 - the resulting signal after the adder 12 (see figure 2).

Figure 4 shows the signal patterns of the proposed device, using, for example, a pseudo-random sequence with a Barker code of 5; p. 41 with the number of x packages in the code equal to 7 (i.e., l; l: i; -l; -l; i; -i).

- 7 Diagram and (Fig. 4) - the result of the received echo signal from one reflecting object after the adder 12. Diagram O is the reference pseudorandom sequence at the input of the correlator 4 from the code register 5. Diagram B is the signal at the output of the correlator 4 from one reflecting object. Plot G is the resulting signal from two reflecting objects spaced in range after the adder 12 (two peaks are visible, each of which corresponds to one of the objects). Diagram D is the resulting signal from two reflecting objects at the output of correlator 4. J On Diagram D, it can be seen that the shape of the double vertex on the signal envelope after correlator 4 remains the same as at the output of adder 12. However, the magnitude of the signal at the output of correlator 4 is 7 times larger. This suggests that the energy of the useful signal increased 49 times in comparison with the prototype, which significantly increases the range of the proposed device. At the same time, antennas with a fat bandwidth not exceeding one octave can be used in each PPC. The advantages of the proposed device can best be used in profilographs or seismic acoustic systems, where the presence of low-frequency, well penetrating into the thickness of the sediment, as well as high-frequency components determining the resolution but poorly penetrating the precipitation are required in the spectrum of the emitted signals. - 8-9 LINKS Hfl sources of INFORMATION

1.Handbook on hydroacoustics. A.P. Evtstov et al. Pub. 2. L. Shipbuilding. 1988 year

2. Reference book on the basics of radar technology. Ed. V.V.Druzhinina. Military Publishing House, Moscow, 1996

3. SEA TECHNOLO & Y. February magazine. 1994 c. Firm DATASONICS. CHIRP SUB-BOTTOM PROFILER CHIRP-2.

4.Golubkov A.G. Special hydrodynamic systems. L. Shipbuilding iijBT

5. Alekseev I.I. et al. Teiri; .i in case of pseudo low-pitched signals. The science. M. 1969

Claims (1)

A device for measuring the delay of an emitted signal or an echo signal in acoustic, hydroacoustic navigation, location or sounding systems, comprising a processing unit connected to the output of a half-wave detector, as well as to a control input of a master oscillator, the output of which is connected to a transceiver complex consisting of a signal synthesizer, the input of which connected to the output of the master oscillator, the transmitter, the output of which is connected to the transmitting (or combined transceiver) antenna, the receiver, connected Go to the receiving (or transceiving) antenna, characterized in that the device is made in the form of several transceiving complexes operating at different frequencies, with a delay circuit included between the synthesizer and the transmitter in each complex, and an additional phase correction circuit introduced in the receiver, in addition, the outputs of the receivers of each complex are connected to a multi-input amplitude adder, the output of which is connected to the first input of the correlator, the second input of which is connected to the master oscillator, and the third input is connected to the output By the code register register of the pseudo-random sequence, the correlator output is connected to the input of a half-wave detector, and the code register output is also connected to synthesizers of each complex.