SU1176276A1 - Simulator of signals side-looking sonar - Google Patents

Abstract

SIMULATOR SIGNALS OF THE SIDE SURVEY HYDROELECTOR containing serially connected clock generator, frequency divider and first sawtooth voltage generator, series connected noise generator and narrowband filter, as well as a second sawtooth voltage generator, the input of which is connected to the output of the clock pulse generator, and adder, the output of which is the output of the simulator, characterized in that, in order to extend the functionality of the simulator by simulating the signals of the shadows image of extensive artificial and natural objects, a threshold block, two selector pulses of a frame, two large-scale amplifiers, two reference oscillators, the first key in series and the first two-threshold comparator and the second key in two, in series the output of the narrow-band filter is connected through a threshold unit to the first input of the adder; the outputs of the first and second two-threshold comparators are connected respectively with the second and third inputs of the adder, the output of the first sawtooth generator is connected via the first and second selectors of the selector (The frame’s operating pulse with the control inputs of the first and second keys, respectively, and through the first and second scale amplifiers, respectively the inputs of the first two-threshold comparator, the output of the second sawtooth generator is connected by Od to the inputs of the first and second keys, and the outputs of the first and second reference oscillator sootSRD are connected with the first and second reference inputs of the second two-threshold comparator.

Description

The invention relates to radio engineering and can be used to simulate sonar signals as well as images on the screen of an indicator of a sonar simulator. The purpose of the invention is to expand the functionality by imitating the signals of the ten-graphic image of extended artificial and natural objects. FIG. Figure 1 shows the structural electrical circuit of the proposed simulator; Fig. 2 shows the time diagrams that explain his works | in Figs. 3 - timing diagrams, according to the work of the two-threshold comparator; in fig. 4 - simulated signals, and the shadow graphic image generated by them of the bottom and objects of the lot. The simulator contains a generator of 1 clock pulses, a divider 2 frequencies, the first and second generators 3 and 4 P1 voltage, noise generator 5, narrowband filter 6, threshold unit 7, adder 8, the first driver 9 of the frame selection pulse, the first key 10, the first two-threshold comparator 11, large-scale amplifiers 12 and 13, the second shaper 14 of the selective frame pulse, the second key 15, the second two-threshold comparator 16, the oscillators 17 and 18 of the reference oscillations The simulator works as follows. The clock pulse generator 1, designed to synchronize the operation of the entire simulator, forms a periodic sequence of short square pulses) (Fig. 2 a) with a tracking period T equal to the tracking (repeating) period of the side-scanning sonar pulses Te 2/C, where C is the speed of sound in water, taken into account in calculations usually equal to 1500 m / s; D is the range of action (due to the low speed of sound propagation in water as compared with the propagation speed of electromagnetic oscillations in the atmosphere of 3-10 m / s, the value of the pulse repetition period for HBO far exceeds the corresponding value for RL.S and is in the limit tenths of seconds to units of seconds (with D 150 m, T 0.2 s). The pulse sequence and. (t) with frequency F 1 / T comes from the output of generator 1 to the input of frequency divider 2, which forms the sequence U ( t) (fig. 2 b), frequency 7 following imp The value of which determines the number of simulated sounding of the bottom of HBO, or the number of lines in a raster (frame) of the simulated shadow image. Since, with a lateral survey, the beam of the sonar antenna is perpendicular to the direction of the carrier, the field of view is a D-width, parallel to the path of the carrier vessel, and therefore a raster survey of the bottom in the rectangular coordinate system is inclined (or flax) distance (x) and the travel distance (y). During the period T, the carrier moves to the distance: -: where V is the carrier speed, which is usually set so that during the period T |, following the zones of the pulsing pulse, the carrier moves by a value of q, numerically equal to the size of the locator resolution element in the direction of the course (axis y) Consequently, the values of T and n, which characterize the extent of the obliquity of the bottom strip, determine the size of the raster image (otherwise known as) of the studied space in the direction of the course. The generator 3, triggered by the pulses U2 (t) from the output of the splitter 2 frequency, forms a linearly variable i.e. sawtooth voltage U (t) (Fig. 2c). This voltage is fed to the inputs of blocks 9, 12, 13 and 14. The second generator 4 of the sawtooth voltage, triggered by pulses and (t) from the generator output i clock pulses, generates a linearly varying voltage U (t) {Fig. 2 g) with a repetition period. It enters the inputs of keys 10 and 15. The noise generator 5 generates normal broadband (white) noise Ur- (t) at the output (fig. 2 d) which, after passing through narrowband filter 6, is limited in width, the spectrum (otherwise colored K As a result, the Uf (t) oscillation (Fig. 2e) at the output of the narrowband filter 6 is an amplitude-modulated oscillation with a random and slowly varying amplitude, i.e. an envelope. The rate of change of the envelope (correlation interval) is proportional to bandwidth dependent fil A trap that can be adjusted by changing the active resistance of the filter, for example, by varying a resistor connected in parallel with the output of the narrowband filter. In the threshold block 7, the voltage | Ug (t) is subjected to a threshold treatment, i.e. compared with the threshold U As a result, a voltage U (t) (Fig. 2 g) is formed, equal to level 1 every time, if the difference in voltage U (t) is positive, i.e., with and (ivb, xC) 7) O with ) -U / 0 The threshold unit 7 is implemented as a comparator based on an operational amplifier, the inverting input of which a threshold is applied (the reference voltage is U, and a voltage is fed to the non-inverting input, which is the input of the threshold unit, and (t), from the output of the narrow-band filter 6. The voltage U supplied from the middle output of the potentiometer connected to the outer leads to the power source E can be adjusted. Thus, blocks 5–7 form a random alternation of short pulses in each dressing (line, which imitates the reflection of the probing signal from the bottom in the opposite direction (bottom reverberation J. A combination of n lines imitates raster two-gradation (O and 1 image of the probing surface ( position 19 in Fig. 4). Through these adjustments, you can set the alternation structure O and 1 (i.e., the noise level) of the raster and, therefore, the structure of the simulated bottom surface (mud, sand, stone, etc.). Blocks 9- 13 intended Yen to generate a bundle of video pulses with a constant or linearly varying duration to simulate the signals of HBO in the path of forming a tenographic image of artificial lengthy bottom and bottom objects (position 20 in Fig. 4 /. The frame pulse shaping device 9 is designed for - neither the length G of the said video impulse bundle and its delay tj, i.e. its location in the interval CO, TCj, and is realized, for example, in the form of a two-threshold comparator of a typical dual comparator consisting of Vuh odnoporogovyh comparators. The voltage U. (t) enters the non-inverting input of the first comparator and the inverting input of the second comparator (m. Inverse) through resistive dividers K. and R. The inverting input of the first comparator and the non-inverting input of the second comparator are connected to the reference voltages Ujj and (J 2 respectively through their resistive dividers. Each of these voltages is removed from the average output of the corresponding potentiometer connected to the power source. As a result, the output of the former 9 a voltage Ua (t) (Fig. 2i) is formed, equal to level 1 whenever the input voltage Ug (t) Uj (t) is between the thresholds Uj, and U .j (Fig. 2) t ... e.), .... g n.-,. p.o.1LgL The middle and width of the discrimination window and, consequently, the values of ck to PY-I are respectively driven by the voltages U Up using potentiometers. The pulse Uj (t) is fed to the control input of the analog switch 10 and opens it at time C. The voltage U, (t) from the input of the key, coming from the second generator 4 of the sawtooth voltage, passes to its output only during the time, i.e. in the form of and (t) (Fig. 2 K), and then goes to the input of the two-threshold comparator II. A two-threshold comparator 11 is designed to produce, in time C, a pack of m rectangular-shaped video pulses. It is implemented similarly to block 9. However, the first and second threshold inputs (respectively, connected via resistors R and R), the inverting input of the first comparator 11 and the non-inverting input of the second comparator 16 are not only their constant reference voltages Ug and and J,, as was the case with the founder 9, but also the linearly varying voltages UQ (t) and Upj (t) (Fig. 3 a) with a period T ,. As a result, the threshold values vary in time according to a linear law (Fig. Z.a), namely with R, R we have: n..4. ., 2 o .-- and ",. C, a); p., (The input voltage Ugj (t) U is compared with these thresholds, and the voltage U (t) is formed at the output of the two-threshold comparator, equal to 1 when the input voltage is between the thresholds TJ (t) and .U.2 ( t) (Fig. 36). Thus, the output voltage and. (t) is a pack of m rectangular-shaped pulses with varying delay tj | (where i I, 2, ..., m I, m ) relative to the beginning of each of the periods of duration .i At the same time, the initial values tjj are determined by the stresses and and Uo2 A. The subsequent increments from pulse to pulse are amplitudes of sawtooth on The outputs Ug (t) and Vg (ty, coming from the outputs of the scale amplifiers 12 and 13). The linearly varying voltage Uj (t) from the output of the first sawtooth generator 3 is applied to the input of each of the scale amplifiers 12 and 13. the amplifier 12, implemented as a differential amplifier, forms a saw-tooth rising voltage at the first output, and a saw-tooth decreasing (inverted) voltage at the second output. Both outputs are connected to a potentiometer, from the middle output of which the output voltage U i (t) is removed. The amplitude (scale) and the sign of the increments (increase or decrease) of this voltage are given by the potentiometer slider. Similarly, the scale amplifier 13 is executed and operates, at the output of which a linearly varying voltage Ug2 (t) is formed. Thus, blocks 9-13 produce a stack of video pulses imitating signals (in HBO) from the acoustic shadow zone behind an artificial extended object of location, forming a shadow graphic image in the HBO recorder in the simplest case in the form of a parallelogram for bottom generic objects of simple geometric shapes (circular and elliptical cylinders, bars, plates, prisms, etc.) or, more generally, in the form of a quadrilateral with relatively straight linear boundaries — for bottom objects of the indicated forms, when one of object is separated from the bottom, for example, in the case of logs half-submerged during timber rafting. For the tenographic image of these objects (. position 20 in Fig. 4J, the reference voltages Ug, -, and U o, g of the imaging unit 9 determine the displacement and size of the image on the y axis (i.e., on the frame), which characterizes the traveling distance and the length of the object in the direction of the carrier’s path, the reference voltages in the comparator 11 determine the displacement and length of the image along the x axis

(i.e., line), which characterizes the slant range of the object and its lateral dimensions, and finally, the voltages Uo (t) and Uo2 (t) are the degrees of inclination оС and non-parallelism fb of the near and far borders of the image defining the angle object and the angle of inclination of the bottom object to the bottom plane.

Blocks 14-18 produce a stack of video pulses to simulate the signals of the tenegraphic image of natural bottom objects or local inhomogeneities of the bottom (pos. 2 in Fig. 4). :

The operation of blocks 14-16 is similar to the operation of the corresponding blocks 9-1 1 due to their identity. The only difference is that the first and second threshold inputs of the two-threshold comparator 16 are supplied with non-linearly varying voltages from the oscillators 17 and 18 of the reference oscillations. As noted, in the simplest case, these may be low-frequency RC harmonic oscillators. The parameters of these oscillations - the frequency and amplitudes can be set using adjustable frequency resistors and potentiometers at the generator output. These parameters define

laws of change of parameters t and сГ ,. . and, therefore, bursts of video pulses can be obtained that mimic the shadow images of various specified configurations. In the more general case, low frequency oscillators of a random process (noise I) can be used as blocks I6 and 17, which further expands the functionality of blocks 1418.

The signals from the outputs of the threshold unit 7 and the two-threshold comparators 11 and 16 are received respectively at the first, second and third inputs of the adder B. The control signal) (Fig. 4 a) combines the incoming signals and simulates the HBO signals in the path of the formation of the sonar tenographic image of the bottom, lrot artificial and natural objects of 1 local inhomogeneities of the bottom (Fig. 46).

All potentiometers included in the individual blocks and intended for the initial installation of the set parameters of the simulated signals for ease of adjustment and expansion of some of the functionality of the simulator can be combined on the console (control).

Oj

12 3

P

four

U l, (l} X HuhuU Vs (b) U (1}

n

P

H-a Thebes. LHAHLHU -. AT

i.

Claims (1)

SIDE REVIEW HYDROLOCATOR SIGNAL SIMULATOR, comprising a series-connected clock generator, a frequency divider and a first sawtooth voltage generator, a noise generator and a narrow-band filter connected in series, as well as a second sawtooth voltage generator, the input of which is connected to the output of the clock generator, and an adder whose output is the output of the simulator, characterized in that, in order to expand the functionality of the simulator by simulating shadow signals of the image of extended artificial and natural objects, a threshold block, two formers of the selecting pulse of the frame, two large-scale amplifiers, two generators of reference oscillations, the first key and the first two-threshold comparator and the second key and the second two-threshold comparator connected in series are introduced, and the output of the narrow-band filter is connected through the threshold block to the first input of the adder, the outputs of the first and second two-threshold comparators are connected respectively to the second the first and third inputs of the adder, the output of the first sawtooth voltage generator is connected through the first and second formers of the selecting pulse frame with the control inputs of the first and second keys, respectively, and through the first and second scale amplifiers, respectively, with the first and second reference inputs of the first two-threshold comparator, the output of the second generator a sawtooth voltage is connected to the inputs of the first and second keys, and the outputs of the first and second reference oscillation generators are connected respectively to the first second and second reference inputs of the second two-threshold comparator.