1. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 1 Source Localization in a Moving Sensor Field Shana L. Woods Computing and Computational Sciences Mentor: Dr. Barhen Jacob

2. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 2 Overview In order to maintain U.S. naval dominance, there is continuing need to develop innovative approaches for near-real-time remote detection of underwater targets. Moving sensor fields can improve detection performance against stealthier targets using large distributed sensor arrays. These sensors are typically sonobuoys, drifting with the wind and the currents.

3. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 3 Typical Mission Scenario  Submerged submarine  Patrol aircraft searching for it  A filed of GPS capable sonbuoys In which the buoys are passive omindirectional sensors  That provide sound pressure measurements of target signal and ambient noise.  Continuously monitor and transmit sensed data via radio link.  Perdiodically sample their positons, which are also transmitted via radio link. Patrol aircraft monitoring GPS- capable sonobuoys.

4. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 4 Source and Sensors Location Synthetic data are generated to validate the correct implementation of the SL algorithms x-z plane projection x-y plane projection

5. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 5 Time Differences of Arrival

6. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 6 Equations or Algorithms

7. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 7 Results

8. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 8 Results A.Compared the effects of different situations i.e. amplitude, pulses and interval lengths.

9. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 9 Data A.Develop a FORTRAN Program to located the source using a closed form solution. ! FORM MATRIX Z DOn = 1,N1 argx = PX(n+1) argy = PY(n+1) argz = PZ(n+1) argd = RD(n) ZZ(n)= 0.5_8 * (argx*argx + argy*argy + argz*argz - argd*argd) WRITE(IS7, * )'ZZ = ',ZZ END DO ! FORM a AND b CALL MATVEC( S5, ZZ, AA, N3, N1 ) CALL MATVEC( S5, RD, BB, N3, N1 ) WRITE(IS7, * )'AA = ',AA WRITE(IS7, * )'BB = ',BB ! CALCULATE RESS RES1 = (AA(1)*BB(1)) + (AA(2)*BB(2)) + (AA(3)*BB(3)) RES2 = BB(1)*BB(1) + BB(2)*BB(2) + BB(3)*BB(3) - 1.0_8 RES3 = AA(1)*AA(1) + AA(2)*AA(2) + AA(3)*AA(3) RES4 = RES1*RES1 - RES2*RES3 RES5= RES1 + DSQRT(RES4)/RES2 RES6= RES1 - DSQRT(RES4)/RES2 WRITE(IS7, * )'RES1= ',RES1 WRITE(IS7, * )'RES2= ',RES2 WRITE(IS7, * )'RES3= ',RES3 WRITE(IS7, * )'RES4= ',RES4 WRITE(IS7, * )'RES5= ',RES5 WRITE(IS7, * )'RES6= ',RES6 ! CALCULATE XS XS = AA-BB*RES5 WRITE(IS7, * )'XS= ',XS DOn = 1,N3 WRITE(IS7,7030)n, XS(n) END DO XS = AA-BB*RES6 WRITE(IS7, * )'XS= ',XS

10. O AK R IDGE N ATIONAL L ABORATORY U. S. D EPARTMENT OF E NERGY 10 Conclusion