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APPENDIKS I

---~---

INTERCALIBRATION BETWEEN RIV ¹¹JOHAN HJORT" AND R/V ¹¹PINRO"

23 MARCH 1991

INTRODUCTION

The intercalibration was carried out on the evening of 23 5130N, 1400W and 5140N, 1258W. March 1991 on a 54 n.mi. track between positions

RIV followed r=JOHAN 0.5 n.mi. HJUkl "' was behind and sailing 10 degrees to the starboard in front and RIV "PINRO"

side (Fig 1). The cruising speed was approximately 9 knots.

The intercalibration was performed on varying consentrations of blue whiting between 400 - 600 depth, but densities of plankton and smaller fish in the upper layers were included.

The equipment and the settings of the instruments were the same as during the joint survey, for details see Table 1.

Integration were done in four channels and the settings were:

Ch 1 100 200 m Ch 2 300 400 m Ch 3 400 500 m Ch 4 500 600 m

The channels width on RIV .. PINRo•• were 99 m.

The navigational log counter onboard RIV "JOHAN HJORT" was used function as a reference of distance, and the integrator reset on RIV ."PINRO" was operated for each nautical mile sailed, promted by signals transmitted on VHF-radio.

The performance. weather conditions were favourable during the entire

ANALVSIS

A detailed analysis of the recording papers from both vessels was done onboard RIV "JOHAN HJORT" _by scientists from both vessels. The recordingson each nautical mile were scrutinized and compared. Data from miles where the two vessels

had obtained different recordings were deleted from further processing. The integrator values for all channels are shown in Table 2, where the deleted data are marked with an asterisk.

(Appendiks)

As i t can be seen from this table, the values corresponds well, except perhaps for the second and the fourth channel, where there was a tendency for R/V "PINRO" to have lower values. A possible reason for this is a difference in threshold -R/V "JOHAN HJORT" had recorded much more plankton and small organisms than R/V "PINRO" in these channels, and the voltage response of EK500 is higher than EK400 /SIORS. But the effect of different thresholding have not been considered to be a severe problem during this blue whiting survey, because in most cases signals from blue whiting consentrations are higher than the threshold level of the echo sounding systems.

Results of the linear regression, using the equation:

s =

~J.Hjort ^A

*

^SA

Pin ro

+ B

are shown in Table 3. In Figure 2, the integrator values for all four channels, as well as total values, are displayed in succession for each n.mi. sailed. A distribution diagram, where the values of R/V "PINRO" are plotted against the corrt=u::;r'nnrl; n~ v~_!u~= ~f RIV "JOHAN HJORT .. , are shown i Figure 3. The analysis show a reasonable good correlation for channel 1, 2, 3 and for total values, but correlation between values in the fourth channel was lower. This is believed to be due to different TVG functioning, when the depth was more than 500 m.

Therefore, 5 extremal points were deleted from this channel during the analysis. However, the arithmetical mean of the integrator values in the fourth channels for all 54 points, gives the same relationship ,as the regression analysis where the 5 extremals were deleted.

After several detailed discussions between the Norwegian and ·Soviet scientists, i t is recommended that the following relationship should be used for the integrator obtained during the spring 1991 blue whiting survey :

~

=

J.Hjort

It is also recommended that the gain and the threshold settings of the instruments should, as f~r as possible, be the same for the participating vessels on future surveys, in order to avoid inaccurencies due to problems described above.

Bergen, 14.05.91

Kaare A. Hansen Alexander Dorchencov

A

" J. HJORT:.

o.·s

n.mile

l . l·

.. · • ..

Fig • 1,

~ailing~ formation.

(Appendiks)

100-200M 300-400 m

INJEO. VALUES

<100 - - - -··-- -·-- INIEO. V"LUES

··l

r

300 ....

200 ..

200 ... r.i

l

DISTI\NCE DISTI\NCE

- f " -PINno () fiJOnT

400-500M 500-600M

INTEO. VALUE

1200 - - - · - · ^-. IN l EO. VA LUE

700 . ··- - - ... ···---····---· · - - - -

tooo

eoo

600

DISTI\NCE OISTI\NCE

-A-PINno o fiJOnT

--- rtNno o fiJORT

TOTAL

tNTEO. VALUE 1600 -· ---·· -··

1400 1200

~~

~·~.

l "\)It ~ ~

1000 eoo , eoo

400.

V ..

^{-~~- ~~--}

li ^V···

200

V

0 l . l l t t l l l t f l l t . l l t l l l f l l l l l t . l . l l f l l l l . l . l l l l t t t l . l l l l

t " ,, 31 41

DISTI\NCE

...."._ rtNno o UJOOT

Figure 2. Observed integrator values.

J. HJORT J. HJORT

400 · - - - -

0---"J

-- /

200,---- ---··-·--·-·-··---·

300 -

200-

100 .

_ _ _ _ _ j _ _ _ _

100 200

PIN RO

400-500M

BOO

800

o

200

150

700 (' HJORT __

u-vu

500-

400 .

300

200

100

() ()

PIN RO

500-600M

jj n n

200

o o

0 l __ l _ . l _ l ___ L ____ l_ __ f __. __ _ J ____ f ___ J_ ... 0 · :..J. ••. __ 1 ... l _ _ l __ _.l _____ l _ _ L __ , ___ I _ J _ __L __ _

o 100 200 300 400 500 600 700 900 900 100011001200 o 50 100 150 200 250 300 350 400 450 500 550 600

PIN RO

Figure

TOTAL

J. HJORT

1400.---

o 1200 .

1000

800

eoo ... .

400 ..

200

o _ , __ , __ ._ ____ , ______ .. _____ ! _ _ • - - -

0 200 ~ ~ ~ 10001200 1~ 1~

PINRO

Plot of corresoondino and regression lines. -

PIN RO

integrator values

(Appendiks)

Table 1.

INSTRUMENT CHARACTERISTICS

Echo sounder Frequency

Transducer

..

_{be am} ^type

Transmitter power (nom.) Range compensation

Attenuation

Puls~length/Band~idth

Basic range Threshold Absorption Sound speed

Integrator Threshold

Gain (output reference)

Absolute calibration:

Date

Reference target

Instrument constant (Ci) Sv transducer gain

TS " "

2-way beam angle

"Johan Hjort"

SIMRAD EK500 38 kHz

ES38B/split-beam 7.1 x 7.1 degr.

2000

w

20 log R

O - 500 m - 82 dB

10 dB per km 1470 m per sec.

BEI/EK500 - 82 dB

40 dB

16.03.91 -33.6 (Cu60)

26.9 27.1 -21.0

"Pinro ..

SIMRAD EK400 38 kHz

30:<30 cm ceram.

8 x 8 degr • 2500

w

20 log R O dB

i.0 msi3.3 kHz O - 500 m - 74 db//1W

8.5 db per km 1491 m per sec

SIORS - 48 dB//1W

(VR 63 mV) 10 dB

09.03.91 -34.1

3.26

-20.4

Tab le ...,

L •

INlEGRATOR _Df\Tf'\

Ulf\I·II·IEl_

l (10-··200 "'

n.m.

t.ta r· nn~u H~'urn

01 5 4

(12 7 j

u:5 _{.t t}

Utl l t.

(15 "3 .t.

(16 j .1.

(17 l l

(18 3 2

(19 l

Jo 24 24

11 47 .•1F1

.12 J.JIJ 93

l3 21(1 383

t'l " 17

1.!:' 3 .,

J I.J 3 J

J 7 2 .l

l (l 3 .t

.1.? 3 l

/1) 4 2

.,..,.

~-·-"

3l

·--' ~·~ _,

35 3/.J 31 :.)0 39 'lO

-"

·-' 16 7 J .t

?6 10 J?

8

J7 .1 J

(J 4 .1.

., .tt ••

J.1 J t .11 .tn J.b 't 1., 4 4 4

---

'l.t 1

42 2

•l::. 2

4'1 4

4 5 _J •l

46 19

4i 1•1

48 34

•19 7

50 13

51 47

::.2 2~17t

53 5 7'7

2 2

31 J2 11, 36 1!.i7t.

501)

377t

t:IIN·IHt:.L ? 30(1-·•1 (1(1 "' PJNno ttJurn

10? l ~211

71.1 J3~5

::)7t l :!.2t

=~" ~~n

22 28

3J. 3'l

20 JIJ

41 54

09 J !)3

t '7'' ' ' 7 '

43 41

26 3•l

28 32

50 6'"!.

:~3 37

8/.1 97

J14 1~)7

0'7 1.30

94 97

4.1.

3f:l b9

on

4U 43 51

"3b l'}

Hl

.1.5

,,

•l 11 H 10 7 9 9 9 lB JO J 1 .U.

J.(l 9

fl (l '1?

85

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608t.

"":" ...,'7

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"l1'l 63'l 767t b02t 'l03 'll7 389

~~'1~1 ~'fJI)

.1 72 .l lt:j

~~ ~:-.t.:l ~~f, 5 J '?fl 2¹J2

.1^{1 .. 11}.1 62

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IJR 65

.... ,,.1 1il1

1 ~-7 J 63 1 ~.n .t .:.5 l ~~4 J 20

•. lb 1'27 12:5 ltJO

tto J.3o

J :::'8 92

.f.(l3 99

32 25

::.n 20

n~. 77

7-Jt) 312

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•t/9

?.1.9 .1.31 131 3!39 :)29

?::.~,

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~8(1

375 4¹)5 36(t 3J4 215 J.53 123 288 322 2¹)2 7?(1 J 6(,

·y O T f\L 100-600 m

P I NP.tl Jl,JOR r 810t 1070t

732 872

::•I.J!;t !U'l'?t

581 65(1

615 571

396 i103

'122 395

313 273 279 302 414 344 4.lb 368 477 469

803 973

683 {.1/,t, 791 1020 668* 1152*

603t 0(.:J9t 662 839 627 771 531 651 '116 5J.J

419 3'11.

647 7'73

5J3 !:'71\

465 'l'15 3Hl 3~5

342 283 4(13 4 l J.

4 32 'l81.1

:!·BO 3'11

3'75 38'l

,.,J8 39~

4(12 411

'l13 4';'1 4tl7 318

J93 .t9~~

109 80

B9 70

J67 163

435 tl5(1

787 350 382 398

692 86'2

1'l63 1321 871 _7'l6 445 'l97 3'?4 413

31Jb 33~,

450 'll?

~186 r:.lb9 490 514 628 516 93J 040

j 'l74t 09~~*

---·---~---

-·---·-··~· ···--··-·- --·-· ··--.-.--·· -··--·-- -·-··-··--··--·---· ---·-

Table 3.

C hanne l

1 2

"T

...

4 Total

(appendiks)

LINEAR REGRESSIONS

A B

0.97 2.0

1.20 -1.5

0.93 29.5

1.09 -20.9

1.03 4.6

Corr.

0.95 0.95 0.95 0.93 0.94