JP2000056011A - Sensitivity tester for remote underwater receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fully automate a sensitivity measuring system with a sensitivity tester for a remote underwater receiver and to improve the precision of measured data. SOLUTION: A transmitting means 23 outputs a transmission signal and a synchronization signal and sends the transmission signal amplified with this transmission signal to a sonar transmission unit 4 synchronously with the synchronization signal. The synchronization signal is transmitted by radio from a transmission antenna 7 and is received by a reception antenna 15. The transmission signal is propagated in the sea as a transmission sound and is received by a measuring reception unit 10. An XY analyzer 18 displays a stationary screen, based on the transmission sound and synchronization signal. The transmission time of the signal wave and the amplitude of the direct wave are measured, based on the wave-form of the stationary screen. A personal computer 19 calculates the unknown sensitivity of the sonar transmission unit 4 based on the data of the applied voltage to the sonar transmission unit 4, the transmission time of the signal wave, and the amplitude of the direct wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a measuring vessel at a required distance from a test vessel at sea, and a measuring transducer having a known sensitivity is suspended from the measuring vessel in the sea as a reference.
When performing a sensitivity test by the pulse method in combination with a sonar transducer fixedly mounted on the hull of a test ship of unknown sensitivity, the synchronization signal required for measurement is performed by radio waves,
For remote underwater transducers that measure the transmission time of underwater sound and the amplitude of the received wave of the direct wave and measure the sensitivity of the sonar transducer using the sound velocity value of the sound speed meter incorporated in the measuring transducer of the reference device It relates to a sensitivity tester. In addition, the present invention
It is applicable as a seaborne sound measuring instrument and a sea tester for various acoustic equipment.

[0002]

2. Description of the Related Art To understand the performance of an underwater transmitter or underwater receiver, such as sensitivity, it is necessary to use a standard calibrated underwater transmitter or underwater receiver of known sensitivity as a reference. In general, measurement is performed in an aquarium facility or the like by combining an underwater wave transmitter or underwater wave receiver with unknown sensitivity.

In order to grasp the performance of a sonar transducer fixedly mounted on the hull of a test vessel, Patent No. 2
As in "Transducer sensitivity tester for acoustic sounding equipment" shown in No. 654419, an underwater transducer with a known sensitivity is attached to a stick protruding from the deck of the test ship and suspended from the side of the sea under the sea. Is going. This means that the measurement frequency is relatively low,
In addition, it is used when the measurement distance is more than ten meters.

The "transmitter / receiver sensitivity tester of the acoustic probe" of the measuring device proposed for the above measurement is a pulse method using a submersible transmitter / receiver of known sensitivity in combination with a sonar transmitter / receiver. The transmission level, underwater sound transmission time, and received wave amplitude of the direct wave are measured by using the digital storage type waveform display, and the measured value and the sound speed value of the underwater sound with respect to the water temperature at the time of measurement are transmitted to the personal computer. The input is used to calculate the unknown sensitivity of the sonar transducer.

That is, the transmission sensitivity S ₀ of the sonar transmitter / receiver as a transmitter is equal to the applied voltage S _E to the sonar transmitter / receiver and the known sensitivity of the underwater transmitter / receiver. Measure the receiving sensitivity M ₀ , receiving level M _E, and distance d between the sonar transducer and the underwater transducer when used. Based on the measured water temperature t, determine the sound speed from the table of the relationship between water temperature and sound speed. It is calculated by obtaining c and substituting it into a simplified expression (3) described later.

The sensitivity M ₀ of the sonar transmitter / receiver as a receiver is a reception level M _E , a transmission sensitivity S ₀ when used as a transmitter of a known sensitivity underwater transmitter / receiver, The applied voltage S _E and the distance d between the sonar transducer and the underwater transducer are measured, and the sound velocity c is obtained from a relation table between the water temperature and the sound velocity based on the measured water temperature t. (4) can be calculated.

[0007] The theoretical calculation formula is obtained by considering the absorption attenuation coefficient α in sound wave propagation in water.
It is shown by equations (1) and (2). _{S 0 + S E -20logd-α} / 1000 + M 0 + A G = M E ···· (1) M 0 = M E - (S 0 + S E -20logd-α / 1000 + A G) ·· (2) α: absorption Attenuation coefficient (dB / km)

[0008]

(Equation 1)

F _t = 21.9 × 10 ^C C = 6.0-1520 / (T + 273.0) where A: constant (1.86 × 10 ^-2 ) S: salt concentration (ppt) f _t : relaxation Frequency (kHz) f: Frequency (kHz) B: Constant (2.68 × 10 ⁻² ) (B = 0 when f> 32) T: Temperature (° C.)

In the case where the measurement frequency is relatively low, the measurement distance is tens of meters, and the sound wave propagation attenuation due to the underwater absorption attenuation coefficient is negligible, 1 and 2 The equations may be calculated using simplified equations 3 and 4. _{S 0 + S E -20logd + M} 0 + A G = M E ····· (3) M 0 = M E - (S 0 + S E -20logd + A G) ··· (4) where M _0: sonar transducer Receiving sensitivity (dB) [dB re 1 V / μPa] M _E = 20 log (V _P / (2 × 2 ^1/2 )) M _E : Receiving level (dB) V _P : Synchroscope amplitude (V S ₀ : Transmission sensitivity (dB) of reference transmitter [dB re 1 μPa / V, at 1 m] S _E = 20 log (V _S / (2 × 2 ^1/2 )) S _E : Reference transmitter applied voltage (dB) V _S: synchroscope amplitude (V) d: Instrument distance (m) [= c × t] c: water sound speed (14c °: 1500m / sec) t: sound wave transmission time (sec ) A _G : Voltage gain of receiving system (dB)

[0011] The "transducer sensitivity tester of the acoustic probe" in this measurement is a device exclusively implemented in a measurement room of a test ship equipped with a sonar transducer. For this reason,
Synchronization required to determine the display position of the underwater sound transmission time and direct wave reception amplitude required to determine the distance between the sonar transducer and the underwater transducer of known sensitivity at the required distance The signal is essential for the measurement.

In recent years, the sonar transducer has become large-scale, and the minimum distance required for measurement in a far field, which is the definition of sensitivity measurement, is increasing. It is 10 meters. FIG. 4 is a sensitivity measurement system diagram when the above-described “transmitter / receiver sensitivity tester of an acoustic sounding device” is used in a far field.

In this case, the working ship 35 separately extends the synchronous signal cable 31 and the transmission signal cable 32 of the measuring transducer 10 of known sensitivity from the test ship 8 to the working ship 35 at a required distance. In this case, the measuring transducer 10 having a known sensitivity is suspended from the work boat 35.

The test vessel 8 has a synthesizer 1 for setting a frequency, a pulse width and a repetition period, a power amplifier 2 for amplifying an electric signal, and a sonar transmission / reception, similarly to the above-mentioned "transmitter / receiver sensitivity tester for an acoustic probe". A voltmeter 3 for measuring a predetermined applied voltage to the vessel 4 and a sonar transducer 4 for transmitting sound waves into water by applying a predetermined voltage are provided.

Further, the transmitted sound propagates to the test boat 8 over a distance d of several tens to several hundreds of meters from the transducer 4 for sonar to the transducer 10 for measurement, and the transmission and reception for the test having a known sensitivity. Corrugator 10
The preamplifier 1 receives the signal and converts the impedance through the transmission signal cable 32 to a low impedance.
2. A band pass filter 13 for passing a signal sound of a required frequency, a main amplifier 14 for amplifying a small amplitude, a synchronization signal input terminal, and a measurement of a sound wave propagation time based on a synchronization signal of a transmission timing and an amplitude measurement of a reception level. , A personal computer 19 for programmatically calculating required acoustic performance values such as sensitivity, transmission level and reception level, and a printer 22 for outputting data.

However, as the size of the sonar transducer 4 becomes larger and the sonar transducer 4 uses a higher frequency, measurement is required to satisfy the condition of the distant sound field. Is a few hundred meters, but the synchronization signal required to measure both the distance d between the sonar transducer 4 and the measuring transducer 10 and the amplitude of the direct wave is indispensable. Absent.

If there is no synchronizing signal, the situation is the same as a situation in which an image of a home television flows without stopping, and there is a problem that the measured distance and the amplitude data of the direct wave cannot be obtained at all. .

A constant value (1) is set as the underwater sound velocity value c.
4c °: 1500 m / sec), it is not possible to cope with fluctuations in the speed of sound due to changes in water temperature or the like, and it is not possible to obtain an accurate distance d.

Further, there is a problem that the distance cannot be converted to the reference distance (1 m) defined in the definition of the sensitivity, and the sensitivity of the sonar transducer 4 cannot be obtained.

When a synchronization signal is received and received by wire by arranging a cable, a synchronization signal cable 31 is additionally provided in addition to the transmission signal cable 32 of the sonar transducer 4 of known sensitivity. At the same time, there is a problem that it is necessary to dispatch a work boat 35 having a deck working facility capable of coping with a scale-up work separated by a distance. At this time, the extension of the cables 31 and 32 at sea requires complicated and complicated devices such as engaging with a buoyant body 33 such as a buoy and preparation work.
There is also a problem that the guard ship 34 is required, which affects costs and safety.

[0021]

SUMMARY OF THE INVENTION The present invention is an improvement of the above-mentioned measuring apparatus in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a sensitivity measuring system using a sensitivity tester for a remote underwater transducer. An object of the present invention is to enable complete automation and improve the accuracy of measured data.

Another object of the present invention is to measure the sensitivity of a sonar transducer mounted on a hull of a test ship at sea by suspending a measuring transducer of known sensitivity from the side of the measuring vessel at a required distance. When the measurement is carried out by the pulse method, the synchronization signal system required for the measurement is made to be a radio wave system, which eliminates the need for wired deployment over the separation distance between the two ships, where sensitivity measurement is likely to be affected by the state of the sea, and preparation for it. To improve the safety of the cable for the synchronization signal system between the test and measurement vessels, and to monitor the crossing vessels between the test and measurement vessels and eliminate the need for a guard ship to prevent it, increasing the cost saving effect. It is to plan.

Still another object of the present invention is to use a synchronization signal transmitted and received wirelessly as a reference so that a transmission time delay is reduced as compared with a transmission signal (transmission sound) propagating in the sea, and a transmission signal (transmission sound) in the sea. The purpose of this is to accurately measure the transmission time.

Another object of the present invention is to provide a transmitting sound transmitted from a sonar transmitter to a measuring receiver based on an input of a transmitting signal, a synchronizing signal received by a synchronizing signal receiving means,
By providing a display measuring means for displaying a still screen based on the, there is to display the received waveform starting from the time of transmission of the transmission signal, and thereby, from the starting point to the direct wave receiving point It is to measure the time for each transmission and automatically measure the transmission time of the transmission signal (underwater sound).

Still another object is to provide an arithmetic means for calculating unknown sensitivity of a transmitter based on voltage applied to the transmitter and data on the transmission time of the signal wave and the amplitude of the direct wave measured by the display measuring means. Is provided, it is possible to convert the distance to the reference distance (1 m), which is the definition of the sensitivity, without any problem, and to accurately determine the unknown sensitivity of the sonar transmitter or sonar receiver.

Another object of the present invention is to provide a distance between a sonar transducer and a measuring transducer at the time of measurement, together with a transmission time, based on a sound velocity value measured by a sound speed meter provided in the measuring transducer. It is to measure accurately.

[0027]

In short, a sensitivity tester for a remote underwater transducer according to claim 1 of the present invention comprises: a sonar transmitter of unknown sensitivity fixedly mounted on the bottom of a test ship;
A measurement receiver of known sensitivity, which is suspended in water from a measurement ship that is separated from the test ship by a predetermined distance, and forms a pair of transducers in combination with the sonar transmitter. The transmission signal is provided on the test ship and outputs a synchronization signal at each predetermined frequency to be measured, and a synchronization signal is output. A transmission signal obtained by predeterminedly amplifying the transmission signal is transmitted to the sonar transmitter while synchronizing with the synchronization signal. Transmitting means provided on the test vessel, for transmitting the synchronization signal output from the transmitting means by radio, and receiving the synchronization signal provided on the measuring vessel and wirelessly transmitted from the transmitting means. Synchronizing signal receiving means, a transmitted sound transmitted from the sonar transmitter to the measuring receiver based on the input of the transmission signal, and a synchronizing sound received by the synchronizing signal receiving means. And a signal, based on the waveform of the still screen every time a transmitted sound is transmitted from the sonar transmitter, based on the waveform of the stationary screen, the transmitted sound is transmitted and then the measurement receiver A display measuring means for measuring the transmission time of the signal wave and the amplitude of the direct wave until receiving the direct wave, and the data of the transmission time of the signal wave and the amplitude of the direct wave measured by the display measuring means. Calculating means for calculating the unknown sensitivity of the sonar transmitter based on the calculated value.

A sensitivity tester for a remote underwater transducer according to a second aspect of the present invention is separated from a sonar receiver of unknown sensitivity fixedly mounted on the bottom of a test ship by a predetermined distance from the test ship. A measuring transducer that is suspended from the measuring vessel that is underwater and that constitutes a pair of transducers in combination with the sonar receiver, and that is provided on the measuring vessel and measures Transmitting means for outputting a transmission signal at each predetermined frequency and outputting a synchronization signal, and transmitting a transmission signal obtained by amplifying the transmission signal to the measurement transmitter while synchronizing the transmission signal with the synchronization signal; and A synchronization signal transmitting means for wirelessly transmitting a synchronization signal output from the transmission means; a synchronization signal receiving means for receiving a synchronization signal wirelessly transmitted from the transmission means, provided on the test vessel; A transmission screen transmitted from the measurement transmitter to the sonar receiver based on the input of the transmission signal, and a synchronization signal received by the synchronization signal receiving unit, and a still screen is displayed based on the synchronization signal. Based on the waveform of the still screen every time a transmission sound is transmitted from the measurement transmitter, the signal wave from when the transmission sound is transmitted until the sonar receiver receives a direct wave is transmitted. Display measuring means for measuring the transmission time and the amplitude of the direct wave, and the unknown sensitivity of the sonar receiver based on the data of the transmission time of the signal wave and the amplitude of the direct wave measured by the display measuring means. Computing means for performing computation.

Further, the measuring transmitter or the measuring receiver of the sensitivity tester for a remote underwater transmitter / receiver has at least a monitor sensor having a sound velocity meter and a salt concentration meter, and the calculating means includes: The unknown sensitivity of the sonar transmitter or the sonar receiver may be calculated including the sound velocity value measured by a meter and the data of the salt concentration in water measured by the salt concentration meter.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sensitivity tester for a remote underwater transducer according to the present invention will be described below with reference to FIGS. FIG. 1 is a sensitivity measurement system diagram in the present invention. In the present embodiment, in order to measure the transmission sensitivity of the sonar transmitter / receiver 4, the sonar transmitter / receiver 4 is used as a transmitter.
The measuring transducer 10 is used as a receiver.
The same or equivalent parts as those in the above-described conventional example are denoted by the same reference numerals, and description thereof will be omitted.

The test vessel 8 has a transmitting means 23 for outputting a transmission signal and a synchronizing signal (trigger signal), a sonar transducer 4 of unknown sensitivity fixedly mounted on the bottom of the vessel, and a synchronizing signal for wirelessly transmitting the synchronizing signal. Signal transmission means 24 is provided.

The transmitting means 23 includes a synthesizer 1 for setting a frequency, a pulse width and a repetition period, a power amplifier 2 for amplifying a transmitted signal, and a voltmeter 3 for measuring a predetermined applied voltage to the sonar transducer 4. And is composed of

The synchronizing signal transmitting means 24 comprises a trigger signal modulating circuit 5 comprising a pulse modulating circuit and a transmitting circuit, a radio transmitter 6, and a transmitting antenna 7 for transmitting a synchronizing signal as a radio signal. I have.

In the synthesizer 1, a synchronization signal (trigger signal) and an outgoing signal synchronized with the synchronization signal are output simultaneously. The transmission signal is amplified by the power amplifier 2 and transmitted to the sonar transducer 4 as a transmission signal. The applied voltage at this time is measured by the voltmeter 3. The sonar transmitter / receiver 4 transmits the transmitted sound into the water by the above-described voltage application in a state synchronized with the synchronization signal.

The synchronization signal output from the synthesizer 1 is converted into a sine wave burst signal by the trigger signal modulation circuit 5 and transmitted from the transmission antenna 7 by the radio transmitter 6.

On the other hand, a measuring transceiver 9 having a known sensitivity suspended from a side of the measuring vessel 9 by a cable 30 and a synchronizing signal for receiving a synchronizing signal from the test vessel 8 are provided to the measuring vessel 9 at a long distance. Receiving means 26, a display measuring means 18 to which the transmitted sound received by the measuring transducer 10 is amplified as a received signal and inputted, and to which a synchronous signal received by the synchronous signal receiving means is inputted; Is provided.

The synchronizing signal receiving means 26 receives the synchronizing signal wirelessly transmitted as a burst signal.
5, a radio receiver 16, and a trigger signal demodulation circuit 17 composed of a pulse demodulation circuit and a reception circuit.

XY analyzer 18 as display measuring means
Has a synchronization signal input terminal and automatically measures the measurement of the sound wave propagation time and the amplitude of the reception level based on the synchronization signal of the transmission timing.

The burst signal wirelessly transmitted from the transmitting antenna 7 of the test boat 8 is received by the wireless receiver 16 by the receiving antenna 15, converted into a trigger signal by the trigger demodulation circuit 17, and generated by the digital XY analyzer 18. To the synchronization input terminal.

The transmitted sound (received signal) received by the measuring transducer 10 is transmitted via the cable 30 to the amplifier 2.
5 is input. The amplifier 25 includes the preamplifier 12, the bandpass filter 13, and the main amplifier 14. The received signal is first subjected to impedance conversion by the preamplifier 12 to become a low impedance signal wave. And
The signal sound (direct wave) of a required frequency is passed by the band-pass filter 13, the small amplitude is amplified by the main amplifier 14, and the amplified signal is transmitted to the digital XY analyzer 18.

In the digital XY analyzer 18,
A synchronization signal and a reception signal are input, and the measurement of the sound wave propagation time and the measurement of the amplitude of the reception level based on the synchronization signal of the transmission timing are automatically measured. That is, the amplitude of the direct wave and the sound propagation time (t) for each transmission are continuously and automatically measured.

FIG. 2 shows a still screen of the XY analyzer 18 at this time. On the screen, a received waveform starting from the time of transmission of the transmission signal (direct wave) is displayed. By measuring the time from the starting point to the direct wave receiving point for each transmission, the propagation time t of the transmitted sound (direct wave) is automatically determined.

That is, the sound wave propagation time (t) is the time t _{1 at} the point where the rising waveform at the forefront of the received direct wave exceeds the preset slice level (Th),
The difference from the time t ₀ starting from the trigger signal is measured and obtained.

At this time, the sound wave propagation time (t) can be obtained by automatically reading from the synchronization output signal of the synthesizer 1 up to the first rising waveform of the received waveform. Further, the amplitude at that time can be obtained simultaneously with the sound wave propagation time (t) by automatically reading the section in consideration of the pulse width of the transmission signal.

As described above, the synchronization signal is transmitted in the air in the air with almost no delay in the propagation time as compared with the transmitted sound propagating in the sea. The transmission time (t) of the transmitted sound in the sea that is transmitted and reaches the measuring transducer 10 can be accurately measured.

It should be noted that the transmission trigger signal has a time delay of a few microseconds to the threshold level of the generated trigger signal and the reception signal, although this is negligible. This time delay can be made as small as possible by a circuit design technique, can be obtained by a separate measurement in advance, and can be used as a correction value in a sensitivity calculation formula.

The measuring vessel 9 is provided with a personal computer (arithmetic means) 19 for programmatically calculating required acoustic performance values such as sensitivity, transmission level and reception level, and a printer 22 for outputting data. I have.

The personal computer 19 sends data of the voltage applied to the sonar transducer 4 measured by the XY analyzer 18, the transmission time of the signal wave, and the amplitude of the direct wave.

In the personal computer 19, the applied voltage to the sonar transducer 4 measured by the voltmeter 3 for each test frequency for driving the sonar transducer 4; the amplitude of the direct wave for each transmission; The amplification degree, the sound propagation time (t) and the sound velocity (c) are substituted into a pre-programmed calculation formula, and the sonar transmission and reception wave fixedly mounted on the hull of the test ship 8 at a distance separated by a distance. The unknown sensitivity of the device 4 is measured.

Further, the value of the transmitter terminal voltage as set in advance is input to the personal computer 19, and the sensitivity is calculated by the equation (2). It should be noted that the preamplifier 12 and the bandpass filter 13 of the receiving system
In addition, the respective amplification degrees of the main amplifier 14 may be measured in advance with respect to the measurement frequency.

Further, in order to measure the transmission sensitivity of the sonar transducers 4 of the plurality of test vessels 8, the measurement transducer 10 of the measurement vessel 9 is used as a reference receiver and each test vessel 8 is measured. The transmission from the sonar transmitter / receiver 4 is sequentially performed to realize the continuous operation.

The embodiment in the case where the transmission sensitivity of the sonar transmitter / receiver 4 is measured has been described above. However, in the case where the reception sensitivity of the sonar transmitter / receiver 4 is measured, the above-described embodiment is used. Conversely, the synthesizer 1, the power amplifier 2 and the voltmeter 3 as the transmitting means 23 are mounted on the measuring ship 9, and the measuring transducer 10 is suspended.

Next, the pulse signal modulation circuit 5 as the synchronizing signal transmitting means 5, the radio transmitter 6, and the transmitting antenna 7 are arranged together.

On the other hand, the test vessel 8 includes an amplifier 25, a digital XY analyzer 18 as a display measuring means,
A personal computer 19 and a printer 22 as arithmetic means are mounted and installed.

Next, the receiving antenna 15, the radio receiver 16, and the trigger signal demodulation circuit 17 as the synchronization signal receiving means 26 are arranged together.

Accordingly, the measuring transducer 1 of the measuring ship 9
The transmitted sound transmitted at 0 is received by the sonar transmitter / receiver 4 and the radio wave (burst signal) of the synchronization signal is received by the receiving antenna 15 of the test ship 8, and the receiving antenna 15, the radio receiver 16 and XY via the trigger signal demodulation circuit 17
The signal is sent to the synchronization input terminal of the analyzer 18. In this manner, the wave receiving sensitivity of the sonar transducer 4 fixed to the hull of the test boat 8 can be measured.

Further, one of the measuring vessels 9 and the plurality of test vessels 8
By transmitting the transmission sound and the synchronizing signal from the measurement ship 9 by combining with the above, the reception sensitivity measurement of the sonar transducers 4 of the plurality of test ships 8 can be simultaneously performed.

In any of the above-described embodiments,
The measuring transducer 10 may be provided with a monitor sensor including a sound velocity meter, a water temperature gauge, a depth gauge, and a salt concentration meter. Sound speed meter,
The measured values of the water temperature gauge, depth gauge, and salt concentration meter are collected in a data logger 20, AD-converted by an interfacer 21, and sent to a personal computer (computing means) 19.

When the measurement value measured by the sound velocity meter is used, a more accurate measurement value than the sound velocity value stored in the personal computer 19 in advance is measured. When this measurement value is sent to the personal computer 19, the sonar transducer 4 and the measuring transducer 10 of the test ship 8 at the time of measurement are transmitted.
Is accurately calculated.

When the measured values of the water temperature gauge, depth gauge and salinity meter are also sent to the personal computer 19,
The data can be collected simultaneously with the measured value of the amplitude of the sound wave at the time of the sensitivity measurement, and extremely useful technical data integrated with the environmental data can be obtained.

[0061]

Next, an example of measuring the attenuation characteristics of a one-way propagation sound distance performed as one of the applications of the underwater sensitivity tester of the present invention will be described. In this embodiment, in the test sea area, a wave is transmitted from the test transducer of the experimental ship at a required relatively high frequency, transmission mode and pulse width, and this is transmitted at a maximum distance of 50 m from the experimental ship to the measurement ship. The waves were received by a measuring receiver suspended from a measuring ship at every distance up to 400 m, and the sound pressure level was measured. The trigger signal required for the measurement at that time was transmitted and received as a radio signal.

The sound pressure level obtained by measuring the one-way propagation sound distance attenuation characteristic is calculated from the value measured by the digital oscilloscope as shown in (7).
Equations were calculated, and sound pressure levels were plotted for each distance to obtain distance characteristics. FIG. 3 shows an example of the result.

FIG. 9 shows the measured salinity S (34 ppt) and seawater temperature t in order to examine the validity of the measured data.
Using (24 ° C), the underwater propagation loss was calculated from the theoretical equation (2) and compared with the estimated value of the sea area at the test site indicated by the solid line. M _P = M ₀₁ +20 log (V _P / (2 × 2 ^1/2 )) (7) M _P : Received sound pressure level (dB) M ₀₁ : Received sensitivity of test receiver ( dB) V _P : Synchroscope amplitude (V)

At the time of measurement, a synchronization signal was transmitted by a radio wave transmission method, and the distance between the devices could be reliably measured.
The results of (1) showed a small variation in the measured values, and a good result almost matching the estimated value could be obtained. As described above, it has been found that the present invention has excellent effects such as simplification of the measurement device configuration, elimination of complicated fluctuation amplitude reading work, and acquisition of data with better measurement accuracy.

[0065]

As described above, in the sensitivity tester for a remote underwater transmitter / receiver according to the present invention, it is possible to completely automate the sensitivity measurement method using the sensitivity tester for a remote underwater transmitter / receiver, and to improve the accuracy of measured data. It is possible to achieve.

In addition, the sensitivity of the sonar transmitter / receiver equipped with the hull of the test ship was measured at sea by measuring a known sensitivity of the transducer from the side of the measurement ship at a required distance, and the measurement was pulsed. In the case of implementation by the law, the synchronization signal system required for measurement is a radio wave system, eliminating the need for wired expansion and preparation for the separation between the two ships, where sensitivity measurement is easily affected by sea conditions, and complicated testing To improve the safety of the cable of the synchronization signal system between the ship and the measurement ship, and to eliminate the need for a surveillance ship that intercepts the crossing ship between the test ship and the measurement ship, and to increase the cost saving effect. It is possible.

Further, by using a synchronization signal transmitted and received wirelessly as a reference, a delay in transmission time is reduced as compared with a transmission signal (transmission sound) propagating in the sea, and the transmission time of a transmission signal (transmission sound) in the sea is reduced. It is possible to measure accurately.

Further, a still picture is displayed based on the sound transmitted from the sonar transmitter to the measuring receiver based on the input of the transmission signal and the synchronization signal received by the synchronization signal receiving means. Display measurement means
It is possible to display a received waveform starting at the time of transmission of the transmission signal. This also makes it possible to measure the time from the starting point to the direct wave receiving point for each transmission and automatically measure the transmission time of the transmission signal (transmission sound).

Further, there is provided arithmetic means for calculating unknown sensitivity of the transmitter based on data of the applied voltage to the transmitter, the transmission time of the signal wave and the amplitude of the direct wave measured by the display measuring means. Gives the reference distance (1
m) can be converted without any problem, and the unknown sensitivity of the sonar transmitter or sonar receiver can be accurately obtained.

Further, the distance between the sonar transducer and the measuring transducer can be accurately measured in combination with the transmission time, based on the sound velocity value measured by the sound velocity meter provided in the measuring transducer. It is possible to

[Brief description of the drawings]

FIG. 1 is a measurement system diagram of a sensitivity tester for a remote underwater transducer according to the present invention.

FIG. 2 is a diagram showing a still screen (display waveform) of the XY analyzer.

FIG. 3 is an example of measuring a one-way sound wave propagation attenuation characteristic according to the present invention.

FIG. 4 is a conventional sensitivity measurement system diagram in a sea test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 4 ... Transceiver for sonar 8 ... Test ship 9 ... Measurement ship 10 ... Transceiver for measurement 11 ... Monitor sensor 18 ... Display measurement means (XY analyzer) 19 ... Calculation means (personal computer) 23 ... Transmission means 24 ... Synchronization Signal transmitting means 26: Synchronous signal receiving means

[Procedure amendment]

[Submission date] June 15, 1999 (1999.6.1
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

[0027]

In short, a sensitivity tester for a remote underwater transducer according to claim 1 of the present invention comprises: a sonar transmitter of unknown sensitivity fixedly mounted on the bottom of a test ship;
A measurement receiver having a known sensitivity, which is suspended in water from a measurement ship that is separated from the test ship by a predetermined distance, and forms a pair of transducers in combination with the sonar transmitter. The transmission signal is provided on the test ship and outputs a synchronization signal at each predetermined frequency to be measured, and a synchronization signal is output. A transmission signal obtained by predeterminedly amplifying the transmission signal is transmitted to the sonar transmitter while synchronizing with the synchronization signal. Transmitting means provided on the test vessel, for transmitting the synchronization signal output from the transmitting means by radio, and receiving the synchronization signal provided on the measuring vessel and wirelessly transmitted from the transmitting means. Synchronizing signal receiving means, a transmitting sound transmitted from the sonar transmitter to the measuring receiver based on the input of the transmitting signal, and a synchronizing signal received by the synchronizing signal receiving means. And, still screen to display the on the basis of,
Based on the waveform of the stationary screen every time a transmitted sound is transmitted from the sonar transmitter, a signal wave from when the transmitted sound is transmitted to when the measuring receiver receives a direct wave is transmitted. A display measuring means for automatically measuring the transmission time, the amplitude of the direct wave, and the absorption attenuation coefficient; and the sonar based on data of the transmission time of the signal wave, the amplitude of the direct wave, and the absorption attenuation coefficient measured by the display measuring means. Calculating means for calculating the transmission sensitivity of the transmitter.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

According to a second aspect of the present invention, there is provided a sensitivity tester for a remote underwater transmitter / receiver of unknown sensitivity which is fixedly mounted on the bottom of a test ship and is separated from the test ship by a predetermined distance. A measuring transmitter that is suspended from the measuring vessel that is underwater and that has a known sensitivity that constitutes a pair of transducers in combination with the sonar receiver, and that is provided on the measuring vessel and performs measurement. Transmitting means for outputting a transmission signal and a synchronization signal for each predetermined frequency, transmitting a transmission signal obtained by predeterminedly amplifying the transmission signal to the sonar transmitter while synchronizing with the synchronization signal, and A synchronization signal transmitting means for wirelessly transmitting a synchronization signal output from the transmission means; a synchronization signal receiving means for receiving a synchronization signal wirelessly transmitted from the transmission means, provided on the test vessel; A transmission screen transmitted from the measurement transmitter to the sonar receiver based on the input of the transmission signal, and a synchronization signal received by the synchronization signal receiving unit, and a still screen is displayed based on the synchronization signal. Based on the waveform of the still screen every time a transmission sound is transmitted from the measurement transmitter, the signal wave from when the transmission sound is transmitted until the sonar receiver receives a direct wave is transmitted. Display measurement means for automatically measuring the transmission time, the amplitude of the direct wave, and the absorption attenuation coefficient,
Calculating means for calculating the reception sensitivity of the sonar receiver based on the data of the transmission time of the signal wave, the amplitude of the direct wave, and the absorption attenuation coefficient measured by the display measuring means. And

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment]

[Submission date] September 10, 1999 (1999.9.1
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

[0027]

In short, a sensitivity tester for a remote underwater transducer according to claim 1 of the present invention comprises: a sonar transmitter of unknown sensitivity fixedly mounted on the bottom of a test ship;
A measurement receiver having a known sensitivity, which is suspended in water from a measurement ship that is separated from the test ship by a predetermined distance, and forms a pair of transducers in combination with the sonar transmitter. The transmission signal is provided on the test ship and outputs a synchronization signal at each predetermined frequency to be measured, and a synchronization signal is output. A transmission signal obtained by predeterminedly amplifying the transmission signal is transmitted to the sonar transmitter while synchronizing with the synchronization signal. Transmitting means provided on the test vessel, for transmitting the synchronization signal output from the transmitting means by radio, and receiving the synchronization signal provided on the measuring vessel and wirelessly transmitted from the transmitting means. Synchronizing signal receiving means, a transmitting sound transmitted from the sonar transmitter to the measuring receiver based on the input of the transmitting signal, and a synchronizing signal received by the synchronizing signal receiving means. And, still screen to display the on the basis of,
Based on the waveform of the stationary screen every time a transmitted sound is transmitted from the sonar transmitter, a signal wave from when the transmitted sound is transmitted to when the measuring receiver receives a direct wave is transmitted. A display measuring means for automatically measuring a transmission time, an amplitude of a direct wave, and an absorption attenuation coefficient obtained by a salinity meter, a depth gauge and a water temperature gauge; and a transmission time of a signal wave measured by the display measuring means and a direct wave. Calculating means for calculating the transmission sensitivity of the sonar transmitter based on the data of the amplitude and the absorption attenuation coefficient.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

According to a second aspect of the present invention, there is provided a sensitivity tester for a remote underwater transmitter / receiver of unknown sensitivity which is fixedly mounted on the bottom of a test ship and is separated from the test ship by a predetermined distance. A measuring transmitter that is suspended from the measuring vessel that is underwater and that has a known sensitivity that constitutes a pair of transducers in combination with the sonar receiver, and that is provided on the measuring vessel and performs measurement. Transmitting means for outputting a transmission signal and a synchronization signal for each predetermined frequency, transmitting a transmission signal obtained by predeterminedly amplifying the transmission signal to the sonar transmitter while synchronizing with the synchronization signal, and A synchronization signal transmitting means for wirelessly transmitting a synchronization signal output from the transmission means; a synchronization signal receiving means for receiving a synchronization signal wirelessly transmitted from the transmission means, provided on the test vessel; A transmission screen transmitted from the measurement transmitter to the sonar receiver based on the input of the transmission signal, and a synchronization signal received by the synchronization signal receiving unit, and a still screen is displayed based on the synchronization signal. Based on the waveform of the still screen every time a transmission sound is transmitted from the measurement transmitter, the signal wave from when the transmission sound is transmitted until the sonar receiver receives a direct wave is transmitted. Display measurement means for automatically measuring the transmission time, the amplitude of the direct wave, and the absorption attenuation coefficient,
Calculating means for calculating the reception sensitivity of the sonar receiver based on the transmission time of the signal wave measured by the display measuring means, the amplitude of the direct wave, and the data of the absorption attenuation coefficient. Features.

Claims (3)

[Claims] A sonar transmitter of unknown sensitivity fixedly mounted on the bottom of a test vessel; and a sonar transmitter suspended from a measuring vessel at a predetermined distance from the test vessel. A measuring receiver having a known sensitivity constituting a pair of transducers in combination with a device, provided on the test ship, outputting a transmission signal for each predetermined frequency to be measured, outputting a synchronization signal, and transmitting the transmission signal. Transmitting means for transmitting a transmission signal obtained by predeterminedly amplifying a signal to the sonar transmitter while synchronizing with the synchronizing signal; and synchronizing provided on the test ship and wirelessly transmitting a synchronizing signal output from the transmitting means. A signal transmission unit, a synchronization signal reception unit provided on the measurement vessel and receiving a synchronization signal wirelessly transmitted from the transmission unit, and a signal transmitted from the sonar transmitter based on the input of the transmission signal. A still screen is displayed based on the transmitted sound transmitted to the measuring receiver and the synchronization signal received by the synchronization signal receiving means, and each time the transmitted sound is transmitted from the sonar transmitter. A display measuring unit that measures a transmission time of a signal wave and an amplitude of the direct wave from when the transmitted sound is transmitted to when the measuring receiver receives a direct wave, based on the waveform of the still screen. Calculating means for calculating unknown sensitivity of the sonar transmitter based on data of the transmission time of the signal wave and the amplitude of the direct wave measured by the display measuring means. Sensitivity tester for underwater transducers. 2. A receiver for an unknown sensitivity sonar fixedly mounted on the bottom of a test ship, and a receiver for the sonar suspended from a measuring ship separated by a predetermined distance from the test ship. A transmitter for measurement of known sensitivity constituting a pair of transducers in combination with a transmitter, provided on the measurement vessel, outputting a transmission signal for each predetermined frequency to be measured and outputting a synchronization signal, Transmitting means for transmitting a transmission signal obtained by predeterminedly amplifying a signal to the measuring transmitter while synchronizing with the synchronizing signal; and synchronizing provided on the measuring vessel and wirelessly transmitting a synchronizing signal output from the transmitting means. A signal transmission unit, a synchronization signal reception unit provided on the test vessel, for receiving a synchronization signal wirelessly transmitted from the transmission unit, and the sonar from the measurement transmitter based on an input of the transmission signal. The transmission sound transmitted to the receiver for synchronization, and the synchronization signal received by the synchronization signal receiving means, to display a still screen based on the transmission signal, every time the transmission sound is transmitted from the transmitter for measurement Display measurement means for measuring the transmission time of the signal wave and the amplitude of the direct wave from when the transmitted sound is transmitted to when the sonar receiver receives the direct wave based on the waveform of the still screen, Calculating means for calculating the unknown sensitivity of the sonar receiver based on data of the transmission time of the signal wave and the amplitude of the direct wave, a sensitivity tester for a remote underwater transducer. 3. The transmitter for measurement or the receiver for measurement has a monitor sensor provided with at least a sound velocity meter, and the calculating means includes a sound velocity value measured by the sound velocity meter. The sensitivity tester for a remote underwater transmitter / receiver according to claim 1 or 2, wherein unknown sensitivity of the sonar transmitter or the sonar receiver is calculated.