NO125783B

NO125783B -

Info

Publication number: NO125783B
Application number: NO428370A
Authority: NO
Inventors: R Brede; E Stenersen
Original assignee: Simrad As
Priority date: 1970-11-10
Filing date: 1970-11-10
Publication date: 1972-10-30

Description

Ekkoloddapparat med regulert mottagerforsterkning. Sonar device with regulated receiver gain.

Foreliggende oppfinnelse angår et ekkoloddapparat med regulert mottagerforsterkning etter forut bestemte tidsfunksjoner under loddeperioden, og som omfatter en forste og en annen mottagerkanal med hver sin forsterker hvorved det kan oppnås lett betjening og til enhver tid maksimal informasjon. The present invention relates to a sonar device with regulated receiver gain according to predetermined time functions during the sonar period, and which comprises a first and a second receiver channel each with its own amplifier, whereby easy operation and maximum information can be achieved at all times.

Ved ekkolodd beregnet for anvisning av fisk er det kjent at mottagerens forsterkning må innstilles i forhold til det dyp som skal undersokes, således at forsterkningen okes med tiden under loddeperioden og således med okende anvisningsdybde, for å In the case of sonar intended for indicating fish, it is known that the receiver's amplification must be set in relation to the depth to be investigated, so that the amplification increases with time during the sounding period and thus with increasing indication depth, in order to

kompensere for den okende totale spredning og svekning av ekko- compensate for the increasing total spread and weakening of echo

loddsignalene under deres forplantning gjennom vannet. Dette kan gjores manuelt, men blir i dag stort sett utfort automatisk, idet det,, f.eks. utlost av senderpulsen, frembringes en tilsvarende reguleringsspenning som styrer mottagerens forsterkning under loddeperioden, hvorved ekkosignalanvisningene blir kompensert for transmisjonstapene i vannet, og som oker med dybden. Et slikt arrangement er gunstig for brukeren, idet vedkommende derved ikke behover til stadighet å etterjustere mottagerens forsterkning for å få en riktig anvisning. the plumb signals during their propagation through the water. This can be done manually, but today is mostly done automatically, as it, e.g. triggered by the transmitter pulse, a corresponding regulation voltage is produced which controls the receiver's amplification during the soldering period, whereby the echo signal instructions are compensated for the transmission losses in the water, and which increases with depth. Such an arrangement is beneficial for the user, as he does not thereby need to constantly readjust the receiver's gain in order to receive a correct instruction.

Et slikt arrangement vil imidlertid ikke for samme innstilling However, such an arrangement will not be for the same setting

sikre riktig kompensasjon for ekkosignaler både fra fisk og hav-bunn, idet de kompensasjoner som kreves for fiskeanvisningene og for bunnanvisningene er forskjellige. Ved ekkosignaler fra fisk har det således i praksis vist seg å være passende med en kompensasjons-funksjon lik ( ho log r + 2<xr), mens det for bunnekkosignaler passer bedre med en funksjon lik (20 log r + 2ocr), ensure correct compensation for echo signals both from fish and the seabed, as the compensations required for the fishing instructions and for the bottom instructions are different. In the case of echo signals from fish, a compensation function equal to (ho log r + 2<xr) has thus been shown to be appropriate in practice, while for bottom echo signals it is more suitable with a function equal to (20 log r + 2ocr),

der log r er den briggske logaritme til den loddete dybde av vedkommende signal i meter og a er svekningskoeffisienten for signalenes forplantning gjennom vann. Ved en kompensasjon passende for fiskeekko, (^fO log r + 2ocr) vil derfor bunnen bli for svakt gjengitt på mindre dyp, og for kraftig på storre dyp. where log r is the Briggs logarithm of the plumbed depth of the relevant signal in meters and a is the attenuation coefficient for the signal's propagation through water. With a compensation suitable for fish echoes, (^fO log r + 2ocr) the bottom will therefore be reproduced too weakly at shallower depths, and too strongly at greater depths.

Dette vil vanskeliggjøre en vurdering av bunnens beskaffenhet. Likeledes vil det skape problemer ved bruk av f.eks. hvitlinje, grålinje, osv., da disse funksjonene gjerne er avhengig av en amplitudemessig vurdering av bunnekkoet. Ved bruk av en kompensasjon passende for fiskeekko vil brukeren med andre ord få problemer med disse funksjonene og bli nodt til stadig å etterjustere inn-koplingsnivået for disse. Omvendt vil ved bruk av (20 log r + 2ar)-funksjonen fiske-ekkoene bli for svakt anvist ved store dyp og for sterkt anvist ved mindre dyp. This will make it difficult to assess the condition of the bottom. Likewise, it will cause problems when using e.g. white line, gray line, etc., as these functions often depend on an amplitude assessment of the bottom echo. In other words, when using a compensation suitable for fish echo, the user will have problems with these functions and will have to constantly readjust the connection level for these. Conversely, when using the (20 log r + 2ar) function, the fish echoes will be too weakly indicated at great depths and too strongly indicated at shallower depths.

Foreliggende oppfinnelse har derfor som formål å fremskaffe et ekkoloddapparat som muliggjor riktig kompensering både for fiske- The purpose of the present invention is therefore to provide a sonar device which enables correct compensation both for fishing

og bunnekkoer. and bottom echoes.

Dette oppnås i henhold til oppfinnelsen ved hjelp av nevnte ekkoloddapparat som omfatter en forste og en annen mottagerkanal med hver sin forsterker, idet apparatet i henhold til oppfinnelsen har som særtrekk at forsterkerne er innrettet for nevnte forsterkningsregulering utlost av apparatets senderpuls og etter hver sin forut, bestemte tidsfunksjon, og en koblingsanordning forbundet med en terskelnivådetektor som er tilkoblet forsterkeren i den annen kanal, samt apparatets sender og som er innrettet for alternativt å koble et felles anvisningsorgan til den forste kanals forsterker ved tilforsel av et styresignal angitt fra terskelnivådetektoren når denne mottar et ekkosignal, f.eks. et bunnekkosignal, hvis nivå eller nivåstigningstakt overskrider en forut innstilt terskelverdi. This is achieved according to the invention with the help of the sonar apparatus which comprises a first and a second receiver channel each with its own amplifier, the special feature of the apparatus according to the invention being that the amplifiers are arranged for the aforementioned gain control triggered by the apparatus's transmitter pulse and after each of its predecessors, determined time function, and a switching device connected to a threshold level detector which is connected to the amplifier in the second channel, as well as the device's transmitter and which is arranged to alternatively connect a common indicating means to the first channel's amplifier by supplying a control signal specified from the threshold level detector when it receives a echo signal, e.g. a bottom echo signal, whose level or level rise rate exceeds a preset threshold value.

Dette apparat i henhold til oppfinnelsen gjor det således mulig å koble et felles anvisningsorgan fra en separat mottagerkanal for fiske-ekkosignaler til en annen separat mottagerkanal for bunnekkosignaler når et bunnekkosignal mottas, idet anordningen kobles tilbake til den forstnevnte kanal når neste senderpuls utsendes. This device according to the invention thus makes it possible to connect a common indicating device from a separate receiver channel for fish echo signals to another separate receiver channel for bottom echo signals when a bottom echo signal is received, the device being connected back to the former channel when the next transmitter pulse is emitted.

Bruk av en kanal for fiskeekko og en kanal for bunnekko gjor det derved mulig å regulere forsterkningen for fiskeekko og bunnekko uavhengig av hverandre etter forskjellige hensiktsmessige tidsfunksjoner. Using a channel for fish echo and a channel for bottom echo thereby makes it possible to regulate the gain for fish echo and bottom echo independently of each other according to different appropriate time functions.

Oppfinnelsen vil nå bli nærmere forklart ved hjelp av et utforelseseksempel og under henvisning til vedfoyde tegning som viser et blokkågema av nevnte utforelseseksempel. The invention will now be explained in more detail with the help of an exemplary embodiment and with reference to the attached drawing showing a block view of said exemplary embodiment.

På tegningen er det vist en konvensjonell ekkoloddsender 1 som The drawing shows a conventional sonar transmitter 1 which

styrer en elektro-akustisk omformer 2 som sender lydpulser ut i vannet. En annen (eller samme) elektro-akustisk omformer 3 mottar reflekterte ekkosignaler fra objekter 1 vannet og fra havbunnen. controls an electro-acoustic converter 2 which sends sound pulses into the water. Another (or the same) electro-acoustic converter 3 receives reflected echo signals from objects 1 in the water and from the seabed.

Disse signaler forsterkes i en forforsterker hvis utgangssignaler avgis parallelt til en reguleringsforsterker 5 med reguleringsfunksjon ( U- 0 log r + 2ar) og til en annen reguleringsforsterker 6 These signals are amplified in a pre-amplifier whose output signals are sent in parallel to a control amplifier 5 with control function (U-0 log r + 2ar) and to another control amplifier 6

med reguleringsfunksjon (20 log r + 2ar). Disse regulerings-funksjoner utloses, som antydet på tegningen, fra senderen 1 ved utsendelsen av en lydpuls i vannet. Utgangen fra regulerings- with regulation function (20 log r + 2 years). These regulation functions are triggered, as indicated in the drawing, from the transmitter 1 by sending out a sound pulse in the water. The output from regulatory

forsterkerne 5 og 6, forer til portene 7 henholdsvis 8, hvis utganger samlet er tilkoblet et anvisningsorgan 11. Utgangs- amplifiers 5 and 6, leading to ports 7 and 8, respectively, whose outputs are collectively connected to an indication device 11. Output

signalene fra reguleringsforsterkeren 6 tilfores også en terskelnivådetektor 9? som, når et bunnekko mottas, avgir en styrepuls til en bistabil multivibrator 10. Denne bistabile multivibrator 10 tilfores også en styrepuls fra ekkoloddsenderen 1, og som er utledet av den senderpuls som tilfores den elektro-akustiske om- the signals from the control amplifier 6 are also fed to a threshold level detector 9? which, when a bottom echo is received, emits a control pulse to a bistable multivibrator 10. This bistable multivibrator 10 is also supplied with a control pulse from the sonar transmitter 1, and which is derived from the transmitter pulse supplied to the electro-acoustic re-

former 2. Når den bistabile multivibrator 10 mottar en puls fra senderen 1, innstilles den i en tilstand som bevirker åpning av porten 7 og lukking av porten 8, slik at signalene fra forfor- forms 2. When the bistable multivibrator 10 receives a pulse from the transmitter 1, it is set in a state which causes the opening of the gate 7 and the closing of the gate 8, so that the signals from the

sterkeren h kan passere reguleringsforsterkeren 5 C+0 log r + 2ar) the amplifier h can pass the control amplifier 5 C+0 log r + 2ar)

og porten 7 for å nå fram til anvisningsorganet 11, som f.eks. kan være en skriver med tilhorende skriverforsterker. Fiskeekkosignaler vil da bli anvist optimalt. and the gate 7 to reach the instruction body 11, which e.g. can be a printer with associated printer amplifier. Fish echo signals will then be directed optimally.

Når et bunnekko mottas, vil det bli tilfort detektoren 9 fra reguleringsforsterkeren 6 (20 log r + 2ar) med en amplitude som overstiger terskelverdidetektorens innstilte terskelverdi. When a bottom echo is received, it will be supplied to the detector 9 from the control amplifier 6 (20 log r + 2ar) with an amplitude that exceeds the set threshold value of the threshold value detector.

Detektoren 9 avgir da en puls som fores til den bistabile multivibrator 10, som derved forandrer sin tilstand og stenger porten 7 samtidig som porten 8 åpnes. Bunnekkoet vil da kunne fores til presentasjonsorganet 11 over reguleringsforsterkeren 6 og porten 8. The detector 9 then emits a pulse which is fed to the bistable multivibrator 10, which thereby changes its state and closes the gate 7 at the same time as the gate 8 is opened. The bottom echo will then be able to be fed to the presentation device 11 via the control amplifier 6 and the gate 8.

Anvisningsorganet får ekkosignalene tilfort denne vei helt til The guidance body receives the echo signals in this way all the way

neste senderpuls går ut, og' en ny styrepuls tilfores den bistabile multivibrator 10 fra senderen 1, hvorved den bistabile multivi- the next transmitter pulse goes out, and a new control pulse is supplied to the bistable multivibrator 10 from the transmitter 1, whereby the bistable multivibrator

brator 10 slår om og atter åpner porten 7 samtidig som porten 8 brator 10 switches over and opens gate 7 again at the same time as gate 8

lukkes. Reguleringsforsterkerne 5 og 6 er utstyrt med separate ordinære forsterkningskontroller slik at det er .mulig manuelt å innstille disse uavhengig av hverandre. closes. The regulating amplifiers 5 and 6 are equipped with separate ordinary gain controls so that it is possible to manually set these independently of each other.

Claims

1. Sonar device with regulated receiver amplification according to predetermined time functions during the soldering period, and which comprises a first and a second receiver channel each with its own amplifier (5,6), characterized in that the amplifiers are arranged for said gain regulation triggered by the device's transmitter pulse

and according to each predetermined time function, and a switching device (7,8,10) connected to a threshold level detector (9) which is connected to the amplifier (6) in the second channel, as well as the device's transmitter (1), and which is arranged for alternatively to connect a common indication device (11) to the first channel's amplifier (5) by supplying a control signal derived from the transmitter's emitted power pulse, and to the second channel's amplifier (6) by supplying a control signal indicated by the threshold level detector (9) when this receives an echo signal, e.g. a bottom echo signal, whose level or level rise rate exceeds a preset threshold value.

2. Sonar device as stated in claim 1, characterized in that the coupling device (7,8,10) comprises two controlled gates (7,8) whose inputs are connected to the output of each amplifier (5,6) and whose outputs are collectively connected to the indicating device (11), as well as a bistable multivibrator (10) whose two outputs are connected to the control input of each gate (7,8) and whose two inputs are respectively connected to the threshold level detector (9) and the transmitter (1), and which is arranged to receive a first state, which involves opening the port (7) which is connected to the amplifier (5) in the first channel and closing the second port (8), when said control pulse from the transmitter (1) is supplied, and another state which involves the opposite state for both gates (7,8), when said control pulse from the threshold level detector (9) is supplied.

3. Sonar apparatus as specified in claim 1 or 2, characterized in that the first receiver channel's amplifier regulation is set to be controlled according to a time function C+0 log r + 2ccr) for optimal attenuation compensation of fish echo signals, while the second receiver channel's amplifier regulation is set to be controlled after a time function (20 log r + 2ocr) for optimal attenuation compensation of bottom echo signals, where log r is the Briggs logarithm of the plumbed depth of the relevant signal in meters, and a is the attenuation coefficient for said signal's propagation in water. •+. Sonar apparatus as specified in claims 1-3, characterized in that the amplifiers (5,6) in the two channels, in addition to the aforementioned automatic amplifier controls, are arranged for manual gain setting separately, for optimal signal direction of the signals in both the two channels.