DE1623356C3 - Method and arrangement for determining the course of the distance of a steadily moving watercraft - Google Patents

Description

Po =

(v ₂ - COSa ₂ - V ₁

At ₂

P1P3

₂ ] -

At ₂

_25th

5. Procedure for determining the course of the distance of a steadily moving watercraft (Ship) from a sound-absorbing watercraft that is also moving steadily (Submarine) by measuring the distance between the vehicles using underwater sound pressure measurements, characterized in that the time segments

Δ U = A t ₂ = A t

are, where

(V ₂ COS OL ₂ - V ₁ COS O ₁

² PiPs - PiPi - P2P3

Po =

p _z = P ₂ + M ² - Iv ₂ M cos α ₂

M = ("2 cos Q ₂ - V ₁ cos C ₁ ) P ₁ (p ₃ - p ₂ )

2PiP3 - P1P2 ~ P2P3

and the heading angle f of the sound-emitting vehicle

Ctg s =: Ctg β

v ₂ sin a ₂

35

40

45

50 noises and then directly connected to the deflection systems of a cathode ray tube (15).

7. Arrangement according to claim 2, characterized in that that behind the two integrators (13) and (14) Chopper (16) and (17) are connected.

8. An arrangement according to claim 6, characterized in that a delay chain (19) is introduced ^{into the channel to the receiver (5) and 90 9-member (12).}

6. Arrangement for carrying out the method according to claim 1 to 5, characterized in that broadband sound receivers (1) to (5) are arranged so aligned that receivers no. 1, 3 and 2, 4 offset from one another by 90 ° form a cross group , in the middle of which a receiver (5) is arranged, whose receiving voltages are fed to two differential channels (6) and (7), whose output voltages u \ and ui form two 8-digit characteristics offset by 90 ° and, after passing through two adjustable amplifiers (8) and (9) are multiplied by the voltage of the receiver (5) rotated by 90 ° in (12) in two multipliers (10) and (11) and given to two integrators (13) and (14) whose time constant is large compared to the periodic portion in the to be located The invention relates to a method and an arrangement for determining the course of the distance of a sound-emitting uniformly moving vehicle (ship) from a likewise uniformly moving, shallow running watercraft (submarine) by measuring the distance between the vehicles using underwater sound pressure measurements.

To determine the distance from underwater sound sources or other emitters, in the following target called, are both active back beam methods that work with time-of-flight measurement of echo sounder pulses, as Also known as passive methods, in which the distance from several bearings of the target emitted radiation energy is determined from different points as a measurement base.

In the case of military use, the active procedures have the disadvantage that the enemy is exposed to the echo sounder pulses give information about your own position. In addition, the bridging Difficult over longer distances, because the echo level is the same due to the way there and back Distance is subject to a much greater decrease than the radiant energy used in the passive method of the target, which only has to cover the one-way distance to receive it. After all, they have Active method has the disadvantage that the measurement information is obtained at time intervals that vary from the to measuring distance are dependent.

Although now with the passive method there is uninterrupted measurement information from the emitter to be located are made available, these methods for determining the distance of the target have nonetheless become available so far have practically not been able to enforce. It is known from US-PS 7 49 436 that the removal of a The radiation source is to be determined by measuring the field strength. The same is stated in US Pat. No. 2,174,785 taught. However, this method only gives relatively inaccurate measurement results.

The determination of the distance by several bearings from different points requires for sufficient measuring accuracy a large measuring base, which a simultaneous bearing of different Points the submarine from (cross bearing) as practically out of the question. As a result, the submarine must by driving one after the other to the predetermined positions of the various points on the measuring base be brought before an evaluation to determine the distance from the various Peilmeßwerte can be made. With this passive method, people are moving to determine the distance Aim not just two, but bearing measurements from four base points at a sufficiently large distance from one another necessary. But such a measurement is very

cumbersome and time-consuming and therefore unsuitable for military use.

The invention is based on the object of a method for determining the distance of wave energy to create radiating targets, the continuously arriving, to be recorded in the passive process Allowed to evaluate target information for a continuous determination of the distance.

This object is achieved by a method that has the characterizing features of claim 1 having.

By using this procedure, an uninterrupted distance measurement is obtained, which after first Determination of an initial distance value is based on purely passive measurement. For small distances the passive measurement can be carried out by cross bearing and for larger distances according to the known four-point basis method.

By using the radiation intensity measurement, the passive output measurement can also be carried out Much simplify and shorten this initial measurement using a three-point basic DF method takes place with additional measurement of the radiation intensities of the source in the three base points.

The device for carrying out the new measuring method is expedient with a control amplifier provided, which can be set to a constant output value and its actuator with a scale for the distance to be measured is connected.

The advantages achieved by the invention are in particular that both to determine the Source sound pressure Po as well as a simple driving system for continuous distance measurement, combined with measurements that can be carried out without difficulty. A simple display device allows Display of direction and distance as soon as the source sound pressure has been determined by calculation is, with all calculations being carried out automatically by appropriately programmed computing systems will.

An embodiment of the subject invention is shown in the drawings and is in described in more detail below.

F i g. 1, 2 and 3 show path diagrams for various Passive method for performing initial measurements according to the invention;

4 shows a device for carrying out the method according to the invention for underwater sound location and

F i g. 5 shows the directional diagram of the receiving arrangement in FIG. 4th

In the first, shown in FIG. 1 shown method of passive distance measurement according to the invention, the observing vehicle, z. B. U-boat, during a first measurement phase, which is used to determine the radiation intensity / 0 of the radiation source to be located, on a straight course a. The target running on the same course b , z. B. a surface vehicle, the screw noise of which is picked up by an underwater sound receiving device of the submarine, will be measured at point A \ of the course line a with a sound pressure p \. At the same time, the direction of the incident sound waves is measured. So the sound pressure p \ and the angle α to point B \ are known. On the other hand, the size of the distance r \ is still unknown. In the time Δ ί the submarine runs from A \ to A ₂ over a distance S \. The noise source changes its location from B] to B ₂ and is then observed in direction β. At the same time, the sound pressure p _{2 is} measured at the observation location A2 , while the distance r _{2 is} again unknown. On the further journey from A2 to A3 over the route S ₂ , the submarine changes its speed, so that with the same transit time Δ t the two routes behave like the two different speeds of the submarine over these routes. The target ship B has covered the same distance on the line b from B ₂ to Bi in the time Δ t and is at the distance r ₃ from the submarine in Bz. At point A3 the direction γ and the sound pressure pi are measured again. The distances η, r ₂ , r ₃ can be determined from the measurements carried out in this way; because the sound pressures behave at the distances as

r =

Po

..n

' ²

_ Po

_ Po

~ 7

In these equations, po is the source sound pressure measured in the far field and calculated back to 1 m from the center of the noise source, the logarithmic measure of which is 20 Ig po known as the "target level". The exponent η depends on the water depth. In deep water, where the sound waves propagate spherically, / 3 = 1. If sound propagates in the form of cylindrical waves, as is the case with very shallow water, for example, / 3 = 1/2.

For the sake of simplicity, calculations are made with spherical sound propagation, i.e. with n = 1. Deviating exponents do not provide any new knowledge and can, if necessary, be introduced later or taken into account in a programmed computer.

From the geometric relationships in FIG. 1 and the values of the sound pressures p \, pi and pa can be calculated po

_ Z ₁ ± η ² , -N [, (S ₁ + S ₂ ) ² - (2S ₁ ) ² ]

p ₀ _ _ _t

whereby

_ 4s _t · cos β _ (S ₁ + S ₂ ) · cos α _ (S ₁ + S ₂ ) cos γ

¹ Pi Pi P ₃

N =

Pi pi

P1P3

The plus or minus sign is determined by the fact that po must be positive. The three distances are now

Po
pi

Po
Pz

and r ₃ = - ^ -.
P ₃

If the exponent π is different, the following applies accordingly

Po

_r " =

P (O

This allows the locus of the observed ship to be drawn by entering the distances r \, r ₂ , ft from one's own known positions Ai, A ₂ , A3 in the directions tx, β, γ . The implementation is expediently carried out by a computer programmed for this purpose.

Once po is determined, then it is then possible, based on the relationship

Po

15th

P (D ■ '■';

to continuously determine the distance by continuously measuring the sound pressure ρ. By plotting the measured direction and distance, the movement data of the observed noise source can be obtained in this way with purely passive methods, and improved values of po can be obtained by adding further measuring points. One can even recognize when the observed vehicle changes course, but only if this course change does not take place during the first two measurement sections Δt .

That in Fig. The example illustrated in Fig. 2 shows how Po can be determined if it is important to maintain your own speed. Here the observed vehicle B runs exactly as in FIG. 1 from B \ to B ₂ further to 2? ₃ at the same times Δ t, and one's own vehicle is running as in FIG. 1 from A \ to A ₂ .

Instead of continuing on the old course at a different speed, your own submarine changes its course by an angle ό and maintains its speed. Also now po can be determined from the sound pressure P ₃ measured at A3 together with the sound pressures p 1 and p ₂

Po

= ~ Z ₂ (±

+ 2N (I -

4 cos β
P2

Gt- 6 )

—Ό)

pi

P ₃

pi

Pn

- ^ - and -i3_

Pn Pn

begins.
The same then applies accordingly

"N

Po

Pn

Pll Pn

Distance values are determined and new measurements lead to better po / p _n values.

A third example of determining the target level po is shown in FIG. This third method is based on taking the measurements with the bearing upright. This may have arisen accidentally from the initial situation, but it can also be brought about consciously. At point A \ the target is observed at angle cc \. The measured sound pressure is p \. In the time Δ t \ a distance v \ Δ t \ is traversed, whereby the bearing direction <x. \ Does not change according to the prerequisite. After the time Δ t \ has elapsed, one ship is at Ai and registers the sound pressure P ₂ . The vehicle's own speed is now changed from vi to V ₂ and the course is corrected in such a way that one drives again with a stationary, ie unchanged bearing, a measure which can be carried out in a short time. The new bearing angle at speed v ₂ is on.

A new period of time Δ t ₂ up to point A3 is run at speed v _2. The sound pressure p3 is measured there. A simple calculation gives the source sound pressure here again

55

etc.

The use of the useful / disturbance ratios instead of the pure sound pressure is particularly important for larger ones Distances are advantageous when the sound pressure and noise interference are still of the same order of magnitude are present. In this case, too, it is advisable to enter the measured values into a programmed computer. which calculates the distance values and then continuously new ones after driving further distances Po =

(v ₂ cos a ₂ - V ₁ cos U ₁ ) P ₁ P2P3 At ₁ At ₂ P ₁ Pz [At ₁ + At ₂ ] - P ₁ P ₂ At ₁ - P ₂ P ₃ At ₂

30th

₃₅ If one chooses the two time segments Δ f, = Δ t ₂ = Δ t,

then the expression for the source sound pressure po is simplified to

Po =

(v ₂ cos a ₂ - V ₁

2piP ₃ - PiP ₂ - P2P3

TV has the same value as in the first example.

Maintaining the airspeed offers the possibility of working with a measurement of the useful / disturbance ratio instead of the sound pressure measurement. There is no need to fall back on absolute values; because at the same speed, the interference level or the interference sound pressure p _{n is} retained. Instead of the source sound pressure po, however, there is a relative _{value PoIp n} , which results from the same relationship mentioned if, instead of the values p \, pi and Pz, the values

Further, in this case, the speed of the observed vehicle becomes

v _z = V v \ + M ² - 2 V ₂ M cos a ₂ , where

M = ("2 ^cos « 2 - "1 cos Qi) pi (P ₃ - Pi)

2P ₁ P ₃ - P1P2 - P2P3, and its heading angle ζ is calculated from

ctg C = _: ctg / ?.

V ₂ sin a ₂

Here, too, it is expedient to work with a programmed computer and, after going through further sections Δt, with a bearing and a renewed change in speed, improved values po can be obtained.

The procedure only fails if you go at a steady pace without changing course drives, because then mathematically indeterminate results of the form result. It is much more it is necessary to carry out the 3-point determination, at which the direction and sound pressure are measured, that either course changes are used while maintaining the airspeed or that at Maintaining your own course with different own speeds in the individual measuring sections is being worked on. Of course it is also possible to change course at different speeds to operate.

F i g. 4 shows a device according to the invention for determining the direction of acoustic signals and signals Sources of noise underwater.

609 531/349

To receive the underwater sound waves, five broadband sound receivers 1 to 5 are provided, the distance between them being small compared to the wavelengths of the sound signals or the sound noises whose direction is to be determined. Four non-directional receivers 1 to 4 form a cross group of two groups 1, 3 and 2, 4, which are angularly offset from one another by 90 °. The receiver 5 is arranged in its center. The separate receiver 5 can also be dispensed with if the total voltage of all four receivers 1 to 4 is formed. The received voltage U \, t / 3 of the two receivers 1 and 3 are connected downstream to a differential channel 6, those of the two receivers 2 and 4, t / ₂ and t / 4 to a differential channel 7.

The difference signals Ue, U ₁ form two 8-digit characteristics /? I and R ₂ (FIG. 5) offset from one another by 90 ° and are therefore referred to below as 8-digit signals. The 8 signals Ue, Uj are amplified in two controllable amplifiers 8 and 9 with a logarithmic characteristic and are multiplied in two subsequent electronic multipliers 10 and 11 with a signal Ub derived from the received signal of the receiver 5 with the all-round characteristic R ₀ , in the following all around Signal called Us , is derived by a broadband 90 ° rotation in a phase shifter 12. The two product signals t / 10, Uw from the multipliers 10 and 11 are then sent to two integrators 13 and 14. The time constant of these integrators is chosen so that it is large compared to the duration of the fluctuations in the observed noises, for example compared to the periods of the periodic impacts caused by the screw speed of ships. The integrated product signals t / 13, t / 14 can be given directly to the two crossed deflection systems of the cathode ray tube 15. Since the integrated product signals represent direct voltages, a point P would then arise as a display, which points from the center of the screen in the direction of the incident sound waves.

For example, falls from direction γ, as shown in FIG. 4 is indicated, the noise appears on the cathode ray tube also in direction γ the display point P. This display point is so much calmed by the integration of the integrators 13 and 14 that it remains practically constant at one point, at least as long as the distance Noise source does not change significantly. However, since an arrow from the center in the direction of γ is clearer to the eye, choppers 16 and 17 are connected behind the two integrators 13 and 14, which generate the DC voltages Un, Uu of the integrators with any frequency that is no longer perceptible to the eye chop up.

The deflection signals U \ e, Uu formed then generate a line Z ₁ which runs from the center in direction γ to the end point P of the DC voltage display. The gain of the two amplifiers 8 and 9 can be adjusted manually to a suitable line length with the aid of a potentiometer. However, an automatic system known per se can also ensure that the line length always remains constant and is adjusted up to a predetermined value.

A special can be used for noises with a partial tone spectrum, in particular screw noises from ships Achieve a favorable useful-disturbance ratio by making sure that in the path between the Receivers 1 and 3 to the difference channel 6 and in the path between receivers 2 and 4 to Difference channel 7 a delay chain is switched on, the delay time of which is the basic period or a whole multiple of the fundamental period of the signal fundamental tone, with here below the signal fundamental tone the baseline of the superimposed line spectrum is understood.

Since the two multipliers 10, 11 using methods of correlation technology between the sum signal and the two differential signals of the crossed groups work, correlate even broadband ones statistical noises due to the delay no longer, but correlate again tone-like, because the Correlation function increases again sharply after delaying one path by the fundamental period. As shown in the figure, the delay can be adjusted by including a delay chain 19 Insert into the channel between the receiver 5 and the 90 ° member 12.

The common control button 20 of the logarithmic potentiometer of the two control amplifiers 8 and 9 contains an arrow 21 which points to an adjustable scale 22 with logarithmic lettering. This scale in turn contains a further arrow 23, which is on a fixed scale 24 with calibrated values of the sound source pressure po or the target size.

The length of the indicator line Z is initially arbitrary.

Is, as described above, either through active localization or by means of passive methods Sound source pressure po or the target dimension of the target is determined, then the rotatable scale 22 is also set her arrow to this value and controls the rotary knob of the two coupled logarithmic potentiometers the amplifier 8 and 9 so that the line length on the cathode ray tube 15 to a predetermined length grows. The arrow 21 of the rotary knob 20 then points to the distance value on the scale 22 is engraved. This distance value indicates the distance from the target.

The scales 22 can be interchanged for different sound propagation conditions.

In deep-sea areas, i.e. in the usual oceans, the scale is chosen so that it spreads like

r =

Po P.

is equivalent to; in coastal shelf areas or sea areas that are relatively flat, such as B. the Baltic Sea near the German coast, you choose the. Scale so that they like a law of expansion

_r 0.7 ₌

is equivalent to.

The electronic version in the form described then gives both the current direction and the Removal using purely passive methods.

Of course, the gain control can also be automated by using the control amplifier

known control circuits each regulated to the same output voltages of the indicating line will.

The specified method can also be transferred to other passive location methods, for example

to the measurement of the infrared intensity of the engine of an aircraft from another moving aircraft or the infrared intensity of the chimney of a ship or when measuring the field strength of radar rays on moving vehicles.

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1. A method for determining the course of the distance of a steadily moving watercraft (ship) from a likewise smoothly moving, sound-absorbing watercraft (submarine) by measuring the distance between the vehicles with the help of underwater sound pressure measurements, characterized in that the sound-absorbing vehicle in a first point A \ on its straight path a measures its own speed vi, the bearing angle / x to the location of the sound-emitting vehicle traveling on its straight path b , the incoming sound pressure p \ and the transit time Δt to a next point A ₂ , in which the bearing of the sound-emitting vehicle gives the angle γ = β , whereupon the vehicle changes the speed from v \ to v ₂ so that in a point A3 reached after a further time Δ t the bearing angle to the point B3 reached at the same time of the sound-emitting vehicle (2) is again the same angle β and the speed V ₂ = V3 = V4 etc. is maintained in such a way that this angle β remains and that the distance from the sound-absorbing vehicle to the sound-emitting vehicle is continuously measured from the relationship: Π = Po
pi Π Po
pi PO where the source sound pressure measured in the far field and calculated back to 1 m from the center of the noise source after the angles <x, β and γ as well as the distances si to S3, sound pressure p \, p2, pi in the first three points A \, A ₂ , A3 have been measured Po = [ZZ? -N [(S ₁ + S ₂ ) ² - (2 S ₁ ) ² ]
N 4S ₁ cos,
pi , V = Ii (S ₁ + S ₂ ) * COS α (S ₁ + S ₂ ) COS γ Pl P ₃ ' 2 COS (α - γ) PlP ₃ VP ₂ / and the sound pressures p \ to p3, the angles α, β, γ and the distances si to 53 from point A3 continue to be measured. 2. Procedure for determining the course of the distance of a steadily moving watercraft (Ship) from a sound-absorbing watercraft that is also moving steadily (Submarine) by measuring the distance between the vehicles using underwater sound pressure measurements, characterized in that = yy- ( z ₂ ± \ JZ \ after reaching point A ₂ and covering the distance s from A \ to A _2, the sound-absorbing vehicle maintains its speed ν unchanged, changes its angle of travel by the amount ö and after covering the same distance s in the Point A3 arrives, from which the current bearing angle of point 5 ₃ ε, measures the sound pressures p \, pi, p3 and from them and the bearing angles to points B \, B ₂ and £ 3 get: 4 cos β Pi cos α + cos (α - δ) cos ε + cos (ε - δ) pi _N = ¹ I ¹ I 2 cos (α- _f ) Pi Pi PiP ₃ amounts to. 3. The method according to claim 2, characterized in that, in addition, the sound pressure p \, p2, fh the interfering sound pressure p "is measured and the values Pi P? ι P "\ Pn Pn Pn are used so that r = Po Pn Pll Pn etc. will. 4. A method for determining the course of the distance of a steadily moving watercraft (ship) from a likewise smoothly moving, sound-absorbing watercraft (submarine) by measuring the distance between the vehicles with the help of underwater sound pressure measurements, characterized in that the sound-absorbing vehicle after Reaching the _{{ 5} point A ₂ its speed from vi to v ₂ and changes its direction so that the point B _{2 reached} by the sound-emitting vehicle in the meantime appears at the bearing angle 1x2 and this speed and direction continues, so that the bearing is a current one Bearing at the angle «2 becomes and