RESEARCH REPORTS OmStOlf NAVAL POSTGRADUATE SCHOOL HONTEREY, CAUFORNIA 93943

NAVAL UNDERWATER SYSTEMS CENTER 'f NEW LONDON LABORATORY ^

NEW LONDON, CT 06320

Technical Memorandum

SEAGAL Digital Data Processing Buoy Acoustic Performance During

BERMEX-83: Quick Look Report

Date: 14 Sept 1983 Prepared by

NUSC TM 831145

Peter D. Herstein Physicist, 3341

Peter C. King ^ Electronics Engineer, 3353

Approved for public release; distribution unlimited.

NUSC TM 831145

PREFACE

This technical memorandum was prepared under NUSC Project No. A63490, Underwater Data Buoy System, Principal Investigator, P. C. King (Code 3'353). Funding was provided by the ASW Environmental Acoustic Support Project (AEAS) Naval Ocean Research and Development Activity, Code 520, C. E. Stuart, Program Manager.

LIBRARY RESE-IRCH REPORTS DIVISION

DEPARTMEN I^V^lfOSfQ^/gUyNE^SHSOL NAVAL uNDERwM&ff-s^s^mam^^^

ff NEWPORT, Rl 0284|

LIBRARY RESEARCH REPORTS OIViSlOM NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA 93943

New London Laboratory New London, CT 06320

IN REPLV REFEH TO:

33A:PH:js 5600 Sen: 3333-13

^^^ 0 2 1983

From: Commanding Officer To: Commanding Officer,

Activity, (Attn: C. Louis, MS 39529

Naval Ocean Research and Development E. Stuart, Code 520), NSTL Station, Bay St

Subj : NUSC Technical Memorandum; forwarding of

End: (1) P. D. Herstein, P. C. King, "SEACAL Digital Data Processing Buoy Acoustic Performance During BERMEX '83: Quick Look Report, NUSC TM 83114-5, 14 Sept 1983

1. A new multi-hydrophone digital buoy system with onboard FFT processing has been developed at NUSC. This system, called SEACAL, underwent initial at-sea engineering tests during Sept '83 as a part of the BERMEX '83 sea trials. The SEACAL buoy was subsurface moored in a deep water location near Bermuda. Over 75 hours of processed data were acquired, including both ambient noise and CW tow data. End (1) presents a quick look of the acoustic results.

2. SEACAL performance during BERMEX '83 has demonstrated the advanced capabilities offered by this new generation data acquisition system. It is significant to note that the rough draft of End (1) was completed and ready for the NORDA BERMEX '83 representative less than 36 hours after buoy recovery. Further data will be presented in the paper "Initial sea test results of a multi-hydrophone digital buoy system with in-situ FFT processing capabilities" on 11 November 1983 at the 106th Meeting of the Acoustical Society of America.

L. FREEMAN By direction

Copy to: DARPA CNO

CNM

NAVELEX

NAVSEASYSCOM

NAVPGSCOL DWTNSRDC NORDA

ONT NOSC NADC NSWC NRL

MPL NISC DTIC (2) ONR

DIA ARL/UT NOO

A & T Tech Servi ces

(COR K. Evans) (OP-095; -098; CAPT E. Young, CDR H. Dantzler, 952D) (4) (SPO PM-2; MAT-0723, -0724 (CAPT J. Harlett), -05 (R. Hillyer), (4) (R. Mitnick, J. Schuster, 612; R. Knudsen, PME-124) (3) (SEA-63R; D. Porter, F. Romano, R. Farwell, J. Shooter, 63R) (5)

(R. Lauer, 320; R. Martin, 150; E. Chaika, W. Worsley, 530; C. Stuart (3), K. Dial (3), 520; N. Goulson, D. Millburn, 350; Library) (13) (B. Adams, T. Kooij) (J. R. McCarthy, C. Persons, 7133; Library) (3) (P. Haas; Library) (2) (Library) (1) (R. Dicus, N. Yen, R. Doolittle, 5150; W. Mosely, 5120; Library) (5) (F. Fisher) (H. Foxwell)

(R. Winokur, 0NR-102B; CAPT E. Craig, T. Warfield ONR-220; G. Hamilton, ONR-420; J. McKisic, 0NR-4250A; (5)

(N. Bedford) (W. Jobst, J. Allen, 7310; R. Merrifield, 7311; R. Swenson, 6200; R. Christensen)(5)

(J. Carnell , N. Messier)

Copy to: 33 33A (Cole, Herstein) 333 331 3311 (P. King) 333s

NUSC TM 831145

NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON LABORATORY NEW LONDON, CT 06320

Technical Memorandum

SEAGAL Digital Data Processing Buoy Acoustic Performance During

BERMEX-83: Quick Look Report

Date: 14 Sept 1983 Prepared by:

Peter D. Herstein Physicist, 3341

/ , JrJt C )'-^^ 'eter C. King ^>' Peter C. King Electronics Engineer, 3353

Approved for public release; distribution unlimited.

NUSC TM 831145

PREFACE

This technical memorandum was prepared under NUSC Project No. A63490, Underwater Data Buoy System, Principal Investigator, P. C. King (Code 3353). Funding was provided by the ASW Environmental Acoustic Support Project (AEAS) Naval Ocean Research and Development Activity, Code 520, C. E. Stuart, Program Manager.

The successful deployment, operation, and recovery of the SEACAL system would not have been possible without the diligent efforts of several individuals and organizations. We would like to thank Mr. Ken Dial (NORDA), Capt. Richie Lambert and the crew of the R/V ERLINE, Mr. Thomas Beaudoin (Code 3353), Mr. Ralph Austin (Code 3353), Mr. Steven Cox (Code 3353), Mr. Richard Noble (Code 3363), Ms. Sherri Herskovitz (3341), Ms. Christine Perry (3341), the personnel of the NUSC Tudor Hill Laboratory and Messrs. Jim Carnell and Nelson Messier of AST Tech Services.

NUSC TM 831145

ABSTRACT

A new multi-hydrophone digital buoy system with onboard FFT processing has been developed at NUSC. Acoustic data from each of eight hydrophones is digitized and real time Fast Fourier Transformed by the buoy's micro-processor. Complex and ensemble averaged spectral results are then written onto a high density digital cartridge tape. An instantaneous dynamic range of at least 72 dB is available over the frequency band 4-350 Hz. The first open ocean test of the system occurred in September 1983 at a deep water location near Bermuda as a part of the BERMEX '83 sea trials. The system performed nearly flawlessly and was recovered intact. Over 75 hours of acoustic data were acquired, including both ambient noise and CW tow measurements. This technical memorandum presents a quick look review of the acoustic results of the sea test.

3/4

NUSC TM 831145

List of Figures

Fig. No.

1

Title

3a

3b

4a

4b

5a

5b

6a

6b

Ship Track of CW tow over SEAGAL for the period circa 1930 to 2030 Z on 09/09/83

Spectrum of hydrophone #1 for the period 2000.58 to 2007.37 Z on 09/09/83

Spectral levels of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 1953.16 to 1959.57 Z on 09/09/83

Spectral levels of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 1953.16 to 1959.57 Z on 09/09/83

Spectral levels of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 2000.58 to 2007.37 Z on 09/09/83

Spectral levels of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 2000.58 to 2007.37 Z on 09/09/83

Spectral levels of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 2008.38 to 2015.16 Z on 09/09/83

Spectral levels of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 2008.38 to 2015.16 Z on 09/09/83

Spectral level distribution of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 1953.16 to 2015.16 Z on 09/09/83

Spectral level distribution of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 1953.16 to 2015.16 Z on 09/09/83

Ship Track of the GW tow commencing 58 nmi west of SEAGAL for the period 0240 Z to 1400 Z on 09/10/83

Spectrum of hydrophone #1 immediately prior to commencement of CW tow from 58 nmi west of SEAGAL

Page

10

11

13

13

13

13

14

U

14

14

15

16

NUSC TM 831145

Fig. No. Title Page

9 Spectrum of hydrophone #1 with the CW source 58 nmi wes-t of SEAGAL 17

10 Spectra of the eight SEAGAL hydrophones with the CW source 57 nmi west of SEAGAL 18

11 Spectrum of hydrophone #1 with the CW source 39 nmi west of SEAGAL 19

12 Spectrum of hydrophone #1 with the CW source 10 nmi west of SEAGAL 20

13 Spectrum of hydrophone #1 with the CW source 1 nmi southeast of SEAGAL 21

14 Received level of the 290 Hz tone as a function of range for hydrophone #1 during the 58 nmi CW tow 22

15 Ambient noise received on hydrophone #1 immediately prior to the CW tow 58 nmi west of SEAGAL compared with system noise 23

16 Ambient noise received on hydrophone #1 immediately prior to the CW tow 58 nmi west of SEAGAL compared with archival measurements 2,4

17 Ambient noise spectra of the eight SEAGAL hydrophones immediately prior to the CW tow 58 nmi west of SEAGAL 25

18 Ambient noise received on hydrophone #1 during the period 0631-0638 Z on 9/9/83 compared with archival measurements 26

NUSC TM 831145

INTRODUCTION

part

The first open ocean test of the SEAGAL autonomous digital buoy system was conducted during the period of 8-11 September 83 as a of BERMEX '83 (ref 1). The system was deployed at 1335Z on 8 September 83 in deep water near the Bermuda Islands, and was recovered completely intact at 2000Z on 11 September 83. The system performed nearly flawlessly and over 75 hours of acoustic data were acquired. All eight hydrophones operated successfully. This technical memorandum presents the acoustic results obtained from a review of the data on 12 September 83.

BACKGROUND

T a ver proce taper Data Trans Data ei ght hydro tape avera wri tt ensem 6.8 m After the p Packa end-t uPd/H resol senso

he SE ti cal ss i ng over

from forme i s ac hydr

phone cartr ging. en on ble s i n pe succ

roces rd-85 o-end z'V2 , ut i on rs we

ACAL b array packa the b

each 0 d. Th qui red ophone

Ens i dge e

Al so ce eac ummed ri od , essfu1 sed da deskt so th with

. In re emp

uoy sy of ei

ge. T and 15 f the e di St over

s at a embl e very 7 , for h 7.8 power plus 0 recov

ta is op com at ens the sy addi t i 1oyed.

stem as conf ght hydropho he array is 0-300 Hz and eight hyd rop ance between the band 4-3 rate of 1.2

averaged pow .8 mi nutes a post-process minutes. On spectra for ne set of co ery of the S removed for puter. The emble averag stem normali on to acoust

i gured nes an confi g has a

hones f requ

50 Hz. spect

er spe nd rep i ng be e bl DC each 0 mpl ex EACAL post-p system ed res zed to i c dat

during d a dat ured wi n acous is di gi ency bi

Spect ra per ctra ar resent amformi k of da f the 8 spectra buoy, t rocess i has be

ul ts ar a CW t

a , dept

BERMEX a acqui th a ge tic ape ti zed a n cente ra are mi nute e wri tt a 6.8 m ng , com ta cons hydrop for ea

he cass ng on a en cali e di spl one obs h and i

'83 si ti 0 ometr rtu re nd Fa rs i s compu fore en to i nute pi ex i sts hones ch hy ette Hewl

brate ayed erved ncl i n

consis n/di g i i c spa of 25

St Fou 2.0 H

ted fo ach a dig peri 0

spectr of the over dropho contai ett- d in dB with

at i on

ts of tal ti al .4 m. ri er z. r al 1

ital d of a are

the ne. ni ng

ref 1 Hz

SCENARIO

The system was deployed at 32°15'N, 65°22'W. This location is 27.7 nmi west of Gibbs Hill Lighthouse, Bermuda. The water depth is approximately 4600 m. The buoy system was subsurface moored such that the array was 2030 m above the sea floor. During part of BERMEX '83, CW signals were recorded. The CW source was an HX-90 transducer in a tow body. Two frequencies were projected: 148 Hz at 166 dB ref 1 uPa ?lm and 290 Hz at 180 dB uPa Olm. The source depth was nominally 91m. Two tows were conducted: (1) over the SEAGAL system, and (2) closing from approximately 58 nmi west of the buoy.

DATA EXAMINED FOR QUICK LOOK

Only ensemble averaged spectra from individual hydrophones have been reviewed so far. Three sets have been examined:" (1) CW tow over the system, (2) GW tow closing from 58 nmi, and (3) ambient noise

NUSC TM 831145

About 75 individual hydrophone spectra have been plotted and listed to obtain a quantitative flavor of the data. This represents only about 1% of the total data acquired.

CW TOW OVER THE SEAGAL SYSTEM

From vi ci ni ty portion o the ensem Table A { The two t addi ti ona ERLINE wh hydrophon hydrophon all eight during th results a recei ved to 2007.3 peri od. results a 3a, 4a , a 148 Hz fo SEAGAL ar 290 Hz. min avera 5dB, (b) the 148Hz 18dB diff hydrophon

1901Z to of the ar f the tow ble avera Page 12) ones at 1 1 tonal a i ch was t es were s e, spectr hydropho

e 1953.16 t 290Hz f 1evels of 7Z, and f For the 2 t 148Hz w nd 5a hav r the 22 ray. Sim Several o ge , the m there is data , an

erence be es appear

2026Z 0 ray. F most d ged spe present 48Hz an t 250Hz owing t imi1ar. al 1 eve nes. Fi Z to 19 or the the 14

i gure 4 008.38Z hile Fi e been minute i 1 arly, bservat aximum less va d (c) b tween t to be

n 9 Sep igure 1 1rectly ctrum 0 s the t d 290Hz

i s bel he sour

To ex 1 s of t gure 3a 59.57Z same ti 8Hz dur b prese to 201

gure 5b combi ne period Figure

ions ca vari ati ri ati on ased on he 290H operati

tember 83 presents over the ver the p abulated can be c

ieved to ce (ref 2 ami ne var he two to shows th

time peri me period i ng the n nts the r 5.16Z tim shows th

d in Fi gu when the 6b prese

n be made on across over tim eyebal1

z and 148 ng proper

the HX- the Shi array, eriod 20 listing 1 earl y o be assoc ). Spec i ati ons nals wer e result od, whi 1

Fi gur ext time esults a e period e result re 6a to source w nts the : (a) du the hyd

e i n the estimate Hz resul

ly.

90 was t p track Figure

00.58Z t of this bserved. iated wi tra from from hyd e each p s for th e Figure e 4a pre peri od

t 290Hz , Figure s at 290 show th

as nomi n composi t ring any rophones 290Hz d

s , there ts. All

owed in t for the 2 present 0 2007.37 spectrum.

The th the R/ the othe

rophone t lotted fo e 148Hz t 3b shows

sents the of 2000.5 for that 5a shows

Hz. Fi gu e results ally over e results given 6. is less

ata than i s about eight

he

s Z.

V r 0 r one the

8Z time the

res at the for

8 than i n an

CW TOW FROM 58 nmi WEST OF THE SEAGAL SYSTEM

This tow commenced at 0240Z on 10 September 83 and finished at 1425Z the same day. The tow track is shown in figure 7. For the first 11 hours the R/V ERLINE towed radially toward the array at a nominal speed of 5 knots. Figure 8 presents ensembled averaged spectra of hydrophone #1 for the period 0230.45Z to 0237.32Z, immediately prior to the start of the tow. No tones can be observed at either 148Hz or 290Hz. At 0240Z the source was turned on at a range of approximately 58 nmi from the SEAGAL system. Figure 9 shows the spectrum of hydrophone #1 for the time period 0238.35Z to 0245.23Z. Note the 290Hz tone now apparent with about a 22dB SNR. Figure 10 shows spectra from each of the eight hydrophones for the next time period of 0246.26Z to 0253.17Z. Fluctuations of about 5dB are observed for the 290Hz tone. Also, the 148 Hz tone can be more readily observed. Between 10-100 Hz all the hydrophones exhibit nearly identical spectra. This could be due to distant shipping.

The 148Hz tone is only intermittently observed until the source range decreases to about 40 nmi. Figure 11 shows the results for hydrophone #1 during the period 0642.02 to 0648.54Z, representing an

8

NUSC TM 831145

estima above recei v the sp Gi ven values tones recei v Si nee shift wou 1 d woul d estima explan 10 and to 134 Betwee associ simi1 a

ted aver the back ed level ectral v the 2Hz immed i a

were exa ed frequ the sour is to be be predi be 290.5 ted rang ati on is 20Hz.

3.00Z, t n the tw ated wit r to Fig

age range of 3 ground. There s of the two t al ues imtnedi at bi n separat i on tely adj acent ctly on bin ce enci es are in ce is being to expected. At cted for the 2 Hz. Figure 12 e of 10 nmi , b currently ava Figure 13 pres he estimated s 0 source tonal h the R/V ERLI ure 1, when th

9 nmi. Both tones can be easi is a 15.4 dB difference betwe

ones. A point to note is the ely adjacent to the two source and Manning weighting, the sp

to the tones would be symmetri nters. Interpolation shows th fact slightly higher than 148H wed toward the SEAGAL, an upwa a tow speed of 5 knots, a shi 90Hz tone, i.e., the received shows results for hydrophones

oth tones are again observable ilable for the large ambient n ents hydrophone #1 for the per ounce range being less than 1 s, note the emergence of the 2 NE. Not surprising, this figu e source was nominally over th

ly observed en the asymmetry of tones. ectral c if the at the z and 290Hz. rds Doppler ft of .5 Hz frequency at an

. No oi se between iod 1336.22Z nmi . 50Hz 1ump re is very e array.

Spectra of hydrophone #1 were plotted for 25 of 90 time periods available during this CW tow. By converting the times to ranges and reading the received level at 290Hz from the tabular listing provided with each plot, a graph of the received level of the 290Hz tone as a function of range was derived and is shown in Figure 14. Although it is tempting to convert this plot to propagation loss by subtracting received level from source level, further precise verification of the actual source levels used is required.

AMBIENT NOISE

A m their s expecte just pr SEAGAL with sy noi se i few ton noi se m with ar with re ments f wind sp deploye of each fi gure. are str more in 5dB bet frequen ambi ent prev i ou

a j 0 r d ystem d i n a ior to system stem n s meas al s , s easure Chi val spect rom a eed i s d over of th In t

uctura depend ween t ci es a noise

s figu

esign goal noise f1oo quiet typ the comme

Figure oise measu ured by sh ystems noi d for this measureme

to a 2.9Hz receiver 1 0-2.5 kno a 25 m ve

e hydropho he 10-100 11y very s ent of eac he ambient bove 150 H

This me re , during

of acoustic data r be wel1 be!ow th e area. Recall th ncement of the GW 15 shows this same red prior to deplo orting the analog se is in general 1 example. Figure

nts of Perrone (re band. His result

ocated 4.4 km belo ts. Recall that t rtical aperture, nes for the same t Hz region the spec imi1ar , whi1e abov h other. A maximu levels of the hyd

z . Fi gure 18 pres asurement was acqu the period of 063

acqui si tion s e ambient noi at ambient no tow from 58 n result (soli

yment of the system input. 5dB or more b 16 shows this f 3). Note t s are the mea w the ocean s he 8 SEAGAL h Fi gure 17 sho ime period as tra between t e 100 Hz the m variation o rophones is o ents a second i red earlier 1.43Z to 0638

ystems is se 1evels i se was m mi west o d line) c system.

Except elow the case com

hat resul n of meas urface wh ydrophone ws the sp the prev

he 8 hydr spectra b n the ord bserved f measurem

than the .26Z

that

easured f the ompared System for a ambi ent pared ts are ure- en the s were ectra i ous ophones ecome er of or ent of

NUSC TM 831145

on 9 September 83. Again, hydrophone #1 is presented but results are similar for the other phones. The solid line represents the measurement results while the 0 symbol represents the same archival comparison used in Figure 15.

CONCLUSIONS

Th hours System at a n over a luPa§l i nterm posi ti observ data h power warran

e SEAC of aco noi se

omi nal 58 nm

m was i ttent oned n ed. T as bee spectr t furt

AL system successfully acquired and FFT processed over 75 ustic data. All eight hydrophones functioned correctly, was well below measured ambient noise. A 290 Hz CW tone level of 180 dB ref 1 uPaiaim was detected continuously

i tow. A 148 hz tone with a nominal level of 166 dB ref continuously detected out to 40 nmi , and then i ly detected out to 58 nmi. When the R/V ERLINE was ear SEACAL, spectral energy centered at 250 Hz was he SEACAL system was recovered intact. Only 1% of the n examined so far, and only ensemble averaged hydrophone a were reviewed. The quantity and quality of the data her analysi s.

REFERENCES

1. Ocean Programs Management Office, "Exercise Plan for BERMEX '83," NORDA AEAS Report No. 180, Aug 1983 (UNCLASSIFIED).

2. M. Ricciuti, personal communication.

3. A. J. Perrone, "Summary of a One-Year Ambient Noise Measurement Program off Bermuda," NUSC TR 4979, 1 April 1976 (UNCLASSIFIED).

10

NUSC TM 831145

1-r

nmi

0-L

I 2026Z 2035Z^

SEAGAL®

4-2011Z

- 2003Z

c

i ' ll955Z

. ' /

-1930Z

1 ■, : ■ ■

\

32*'16'N

32"'14'N

32«12'N

65°24'W 65°22'W

Figure 1

Ship Track of CW tow over SEACAL for the period circa 1930 to 2030 Z on 09/09/33

11

SEflCAL OfiTA BUOY 8 SAMPLE ENSEMBLE AVERAGE, 2 Hz BANDWIDTH

tn

09

130

125

120

115 -

100 -i_

150 200

FREQUENCY CHz)

250 300 350

HYD. * 1 09/09/83 2000.58 TO 09/09/83 2007.37

n St

Spectrum of hydrophone #1 for the period 2000.58 to 2007.37 Z on 09/09/83

Figure 2

fM

IT. CACAL. DATA IJUOV

Maval Uriderwdler Sybteais Center BCRMEX '83

HVl>. ' 1 HYO SENS 178.5 dB re IV/uPa TftPE BLOCK / 32B0 09/09/83 2000.58 TO 09/09/83 2007.37 G • 0 P«100 - 46.03 Of- "0 S.F • 46 CAL FILE CREATED 08/25/83

FREQ SOUND PRESSURE LEVEL (dB re uPa//Hz)

0 110.43 101.25 -23.33 -30.86 86.19 94,51 99.09 97.34 95.09 90.39 20 94.03 92.75 92.18 95.74 93.75 91.06 92.06 85.32 92.32 92.14 rj 40 91.83 99.04 99.92 96.70 86.55 94.87 93.18 91.91 96.70 94.11 g 00 88.23 91.56 94.74 93.98 88.82 84.77 85. 18 88.00 ei.93 83.50

r- rn 90 86.99 86.20 67.30 87.16 85.77 80.85 83.14 81.54 80.47 -46.12 >

too 77.19 82.46 82.37 78.56 73.65 82.00 81.86 -47.09 73.17 73.15 ito 75.93 72.79 72.73 79.61 72.50 72.42 72.26 -48.25 72.07 78.97 140 74.88 76.56 74.68 99.38 105.06 98.74 71.20 79.64 77.11 71.03 160 70.92 -49.55 -49.65 76.70 -49.83 73.51 73.44 73.39 78.08 76.24 180 -50.29 76.03 79.97 77.66 72.81 -50.67 74.48 69.58 75.52 75.46 200 -51.07 72.31 69.26 78.73 79.11 78.57 -51.46 68.90 73.59 73.54 220 76.47 68.63 -51.86 68.49 73.22 73.13 -52.13 76.00 68.17 84.82 240 86.65 87.92 89.28 89.79 93.61 97.40 97.96 89.82 87.65 80.52 260 79.76 -53.01 -53.07 -53.12 -53.16 67.20 71.92 75.55 73.07 70.03 280 76.97 -53.49 72.90 B8.16 119.80 125.66 119.60 92.42 95.05 88.82 300 72.53 74.24 69.42 78.41 74. 12 66.28 69.24 70.95 -54.26 66.14 320 75.66 75. 16 73. 16 66.21 -54. 12 -53.99 66.57 66.79 -53.37 -53.02 340 -52.65 71.22 68.67 -51.22 -50.65 -50.06

1*1

Co

00 to

4^ tn

Spectral for the

1evels of the received 148 '"^^'l^^,l9ht SEAGAL hydrophones during th period 1953.16 to 1959.57 Z on 09/09/83

Hz tone e

125

N X w 115 a. a.

«^ m

^ 105

Q.

95-

f = 148 Hz 1 = 1953.16 TO 1959.57Z(09/09/83)

Figure 3a

—r- 0

Spectral levels of the received 290 r,z Lon tor the eight SEAGAL hydrophones during"h period 1953.16 to 1959.57 Z on 09/09/83

tone le

125

115

105-

95

f = 290 Hz t = 1953.16 TO 1959.57Z

Finure 3b

—r- 0 2 4

-r- 6

ID

CO

125

N

1 115 m a. a.

»

m 105 ■D

a.

95

f = t =

148 Hz 2000.58 TO 2007.37Z(09/09/83)

■ Fiqure 4a

*\^ -—•——*

1 1 —1 1 1—

1

HYDROPHONE NO.

125-

115

105

95

f = 290 Hz t = 2000.58 TO 2007.37Z

Figure 4b

—r- 0

HYDROPHONE NO.

-I—

7

CO

Spectral levels of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 2000.58 to 2007.37 Z on 09/09/83

Spectral levels of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 2000.58 to 2007.37 Z on 09/09/83

spectral levels of the received 148 Hz tone for the eight SEAGAL hydrophones during the period 2008.38 to 2015.16 Z on 09/09/83

Spectral levels of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 2008.38 to 2015.16 Z on 09/09/83

130

N I 2 120-1 a.

"S CQ 5 110

a.

100

f = 148Hz t = 2008.38 TO 2015.16Z

Figure 5a

130-

120-

110-

100

f = 290 Hz 1 = 2008.38 TO 2015.16Z

Figure 5b

—r- 5

130

N X 15 120 3.

0)

m

Q.

110-

100

f = 148 Hz ALL 3 PREVIOUS TIMES

Fi Qure 5a

f = 290 Hz 130- ALL 3 PREVIOUS TIMES

^^^^ferzJ 120- ^-■^^i^^/f-'^ w

Figure Gb 110-

100 - ' 1 1 1 1 1 1 1 1

HYDROPHONE NO. HYDROPHONE NO.

cz GO

00

in

' I

Ui

itral level distribution of the received 48 'iz tone for the eight SEAGAL hydrophones iiring the period 1953.16 to 2015.16 Z on the

1'J 'j^/SS

Spectral level distribution of the received 290 Hz tone for the eight SEAGAL hydrophones during the period 1953.16 to 2015.16 Z on 09/09/83

32''20'N- 1

0240Z 4- 0400Z 0500Z 0600Z 0700Z

0800Z 0900Z 1000Z

—^— 1100Z 1200Z

SEAC

1300Z/^

AL

1

32*10'N- 1 1400Z

66»40'W 66»20'W ee'oo'w 65040'W 65''20'W

Ship Track of the CW tow commencing 58 nmi west of SEACAL for the period 0240 Z to 1400 Z on 09/10/83

I'll'! 0 nmi 5

in

CO 00

Figure 7

vO

SEAGAL DATA BUOY 8 SAMPLE ENSEMBLE AVERAGE. 2 Hz BAHDWIDTH

100

95 -

90 -

35

30 -

, 75

3.

^0 -

65 -

60 -

55 -

SO 150 200

FREQUENCY CHj)

350

HYD. / 1 09/10/83 0230.45 TO 09/10/83 0237.32

CO

Spectrum of hydrophone #1 immediately prior to commencement of CW tow from 58 nmi west of SEAGAL

Fifjure 8

00 CO

-1^ CJ1

SEACflL DATA BUOV 8 SAMPLE ENSEMBLE AVERAGE, 2 Hz BAMDWIDTH

100

1*

o to

HYD. f 1

150 200

FREQUENCY CHz)

50 300 350

09/10/B"! 0238.35 TO 09/10/83 0245.23

Spectrum of hydrophone #1 with the CW source 58 nmi west of SEAGAL

Figure 9 00

SEACAL DATA BUOY e SAMPLE ENSEMBLE AVERAGE, 2 Hi BANDUIDTH

100

60 -

55

50 ■■*—^^—>-^^H^*-~^i^-l ■^—^-^—*— I I I ■ ■ 50 100 ISO too

FREQUENCY CHs)

eso 300 350

09/10/S3 0246.26 TO 09/10/83 0253.17 CO

SEflCAL DATA BUOV 8 SAMPLE ENSEMBLE AVERAGE, 2 Hz BAHOWIOTH

100

in •St-

CO CO

t/)

HVD. * 1

50 100 150 £00

FREQUENCY (Hz)

zso 300 350

09/10/83 0642.02 TO 09/10/83 0648.54

Spectrum of hydrophone #1 with the CW sourco 39 nmi west of SEAGAL

Figure 11

o (M

SEACAL DATA BUOY 8 SAMPLE ENSEMBLE AVERAGE. 2 Hz BANDWIDTH

HYD. / 1

150 200

FREQUENCY CHz)

350

09/10/83 1140.28 TO 09/10/83 1147.11

IV) Spectrum of hydrophone #1 with the CW source 10 nmi west of SEACAL

CO o

CO CO

Figure 12

SEACAL DATA BUOV B SAHPLE ENSEMBLE AVERAGE, 2 Hz BAHDWIOTH

tn

CO

o to

130

125

120 -

115

1 to

105

o ^5

90 A

HYD. * 1

50 100 A

150 200

FREQUENCY CHz)

A 250 300 350

09/10/H3 133G.2? TO 09/10/83 13'13.00

Spectrum of hydrophone #1 with the CW source 1 nmi southeast of SEACAL

Figure 13 CM

130-1

9

^ 120-1

N X « a.

110-

ffi

Q.

100-

90

0 0

10

0 0 0

0 0 0

0 0

29 30

RANGE (nmi)

—r- 40

—r- 50

0

0 —I

60

Ke^-iived level of the 290 Hz tone as a function of range for hydrophone #1 during the 58 nmi C W •. 0 rt

Figure 14 CO CO

SEACflL DATA BUOV e SftMPLE ENSEMBLE AVERAGE, 2 Hz BANDWIDTH

AMBIENT NOISE IMMEDIATELY PRIOR TO CW TOW 58nml WEST OF SEAGAL (02300237Z, 09/10/83) SYSTEM NOISE (1332-1339Z, 09/07/83)

a z 3 o

IT)

oo

C_3 CO

100 150 200

FREQUENCY CHi)

250 300 350

HYD. » J 09/10/83 0230.4"5 TO 09/10/83 0237.32

Ambient noise received on hydrophone #1 immediately prior to the CW tow 58 nmi west SEAGAL compared with system noise

of

f^inure 15 (SI

SCACAL DATA BUOY e SAMPLE ENSEMBLE AVERAGE. 2 Hs BANDWIDTH

-1. 100 ISO tie

rREaUENCV CHl)

250 30 D 350

HYO. * 1 09/10/83 0230.-tS TO 09/10/83 0237.32

Ambient noise received on hydrophone #1 iiiiiiiediately prior to the CW tow 58 nmi west of SEAGAL compared with archival measurements

^inure 16

o

00

sEflCflL DflTfl rvnv 9 SAMPLE ENSEMBLE flVERflOE, 2 Hi BflNDWlDTW

100

in

CO CO

150 eoo

rREQUENCY CHi}

8S0 300 350

09/10/93 0230.45 TO 09/10/93 0837.32

Ambient noise spectra of the eight SEAGAL hydrophones immediately prior to the CW tow 58 nmi west of SEAGAL

Figure 17 rg

SEACAL DATA BUOY 8 SAMPLE EtISEMBLE AVERAGE, 2 Hz bAMDWlDTH

00

10b

100

35

a. 3

1/

ca- ll

r) ui \fi u Bt a. o z

o en

70

65

60

55

AMBIENT NOISE DURING THE PERIOD 0631-0638Z ON 9/9/83 PERRONE ARCHIVAL AMBIENT NOISE, MEAN FOR 0.0-2.5 kt WIND, DEEP OCEAN NEAR BERMUDA

VAH^

_L_ _1_

50 100 150 200

FREOIil NCY (Hz)

250 300 150

HYD. * 1 09/0a/o3 nf^l 43 TO 09/09/b^ 0638.26

Ambient noise received on hydrophone #1 during the period 0631-0638 Z on 9/9/83 compared with archival measurements

Figure 18

CO o

oo CO

-".jj'r* 'jr-.ffl-vff'.^tf^^:-'- ■■:- '^v-y^?-■ ■'*s. i.^qga-^.L::.:. •-!

NUSC TM 831145

02232 03 0302 039 10 101

20 32 3211

3212 , 3213

3232

'■. 3233 3292 33 33A

33A1 33A2 33A4 33B2 33B3 33C 33C6 3301 3302 331 3311

3312 3313 3314

> 332 ' '•' 3321

3322

3323 333 3331

3332

3343 3422 363 3643 38 3824 3844 413

B. D. F. D. M. E. We W. J. J. Sw J. L. 0. Mi S. A. L. B. M. G. LC CD R. D. W. LC T P. R. W. A. A. J. C. C. W. M. Wh H. W. M. Du Pe R Th R E. D. P. J. J. R. J.

I I I p I 11 I

M cci one hy /onWi nkle , F. Di Napoli [by, T. Cummings, P. Scully-Power, jle, R. Hasse ^earwaters

A Lesick , J. Lau,

L. Maples , F,

r 1 "

N. Owsley ,

R. Kneipfer, D. Tagliafe

Delacruz, J. Mars

G.

rri

h, J

LaCoe Walters Fi 1 i pi ni

V Eby,

i gle, R. Hasse C1earwaters Ki ngsbury Fay, D. Kennedy,

ope Ferrie, J. lanniello, K. Kne Ng, A. Theodorau Abraham, G. Connolly Jr., G.

n g r 0 n e . , . ,-•,.- ■ • Ko '^, ; i •• -v > ; M Ellinthorpe ;=->;'fi-!;: ,' ^i:'^* - ■ Freeman Cole, P. Herstein (3), S. Santaniello, M. John! Ricci uti (2) VJ ■ i-. ■, - Mayer, J. Gallagher

DR J. Malay iR J . Moul son ,. s, Soccoli Counsel 1 or Hay, J. Hanrahan, R.

DR W. Sander B a t em a n i s ' ( ■ -: c j ^ 5'-: , H ' ' v ' Cabl e ' ;;;.,. "^ ..:' '; 1^^?' Boi vi n - ■ - -■ ■ - ■ «. - : -r Hazard, R. Nadeau, S. Cox, D. DiTullio, P. King (5) Moorcroft, B. Wardle ■>" BQ^i.Hoin George, M. Hundt, R. Gregor , E. Harri s Carter, R. Dwyer, A. Brown , R. Radli nski

ison ,

J 1 '

LaPlante (3)

Nadeau, S. Cox, D. B. Wardle, T. Beaud Hundt, R. MacDonald

, U. U1 I I

Beaudoi n

Brown , Konrad

Harri s , ... Dwyer, A. Nuttal 1 R. Ra-^i—"'''

Dirutner, D. Brown, R. Malone, R. Noble, T. itaker, P. Seamen Ware, R. Hersh, H. Phelps, Jr. . j, , Schumacher Fecher, J. Gorman, D. Browning, lea, S. Herskovitz, P. Koenigs, 'ry, W. Roderick, A. Saenger, J. Deavenport, B. Dedreux, D. ' "" mson , H. Wei nberg Wilkinson

omson , H. Wilkinson Soderberg Short Mello Kyle, Vi sneuski Weish , R. Rump Archer, F. Eno

Lee

J . Chester , R. R. Nielsen, C. Syck H. Sternberg, 1

: ';■;

f (2)

30

NUSC TM 831145

601 T. Bell 701 R. Streit 73 D. Quigley

INTERNAL COPIES - 139

31

u^itl98