Ocean Modeling for UUV Path Planning

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1 Ocean Modeling for UUV Path Planning Peter C. Chu Department of Oceanography Naval Postgraduate School Sponsored Jointly by CRUSER ($85,344 and Naval Oceanographic Office ($10k

2 Mul?- Disciplinary/ Mul?- Ins?tu?onal Project with Par?cipa?on of 4 US Navy Peter Chu, Kwang Song Chenwu Fan Tom WeKergren Students Oceanography Applied Mathema?cs NPS NUWC- Newport Ron Betsch Mine Warfare NAVO Peter Fleischer Sedimentology NAVO Frank Bub Ocean Modeling NAVO

3 Four US Navy METOC Theses LCDR Paul Ku?a, Intelligence fused Oceanography for ASW using Unmanned Underwater Vehicles (UUV (Secret. MS in Meteorology and Oceanography, March 013. LT Thai Phung, Analysis of Bioluminescence and Op?cal Variability in the Arabian Gulf and Gulf of Oman for Naval Opera?ons (Restricted. MS in Meteorology and Oceanography, June 013. LT James Fritz, Computer Aided Mine Detec?on Algorithm for Tac?cal Unmanned Aerial Vehicle (TUAV, MS in Meteorology and Oceanography, December 013 LT Mary Doty, Analysis of Ocean Variability in the South China Sea for Naval Opera?ons MS in Meteorology and Oceanography, December 013.

4 Journal Publica?ons Chang, Y.- C., R.- S. Tseng, G.- Y. Chen, P. C. Chu, and Y.- T. Shen, 013: Ship rou?ng u?lizing strong ocean currents. Journal of Naviga.on, 60, doi: / S Chu, P.C., S.E. Miller, and J.A. Hansen, 013: Fuel- Saving Ship Route Using the Navy s Ensemble Meteorological and Oceanic Forecasts. Journal of Defense Modeling and Simula.on, in press.

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6 ArJficial PotenJal Field Method

7 PotenJal Field showing two closely space obstacles create an local minima

8 Stream Line Method

9 UV- " Static Obstacle Avoidance Solutions " Circular Obstacle, Conve hull type " Assume speed and position of Obstacle = = m k k k k g g b b y b b a b b y b b a C y y mc y mc ( ( ( ( ( ( tan tan ( tan ψ - Stream function for static obstacles:

10 " Moving Obstacle Avoidance " Moving Obstacle Solutions " Assume that we know speed and position of moving obstacles - Stream Function for Moving Obstacle ψ = mc tan 1 1 y ( + mc1 tan 1 y y g g C a m yi k k k k = v + k 1 k ( bk + ( y b ( bk + ( y b ( y b + b {( b + ( y b } UV- a ( y b + b {( b + ( y b } v

11 The potential and streamfunction methods are not for the real ocean Analytical Stream Functions: ψ = mc tan 1( y + mc tan 1 1 C Sta?c Obstacles m k= 1 tan 1 a 1 ( b y b ( b + ( k y y a ( b ( b + ( g g y b k + b + b k y y y 1 1 ψ = mc1tan ( + mc1tan C Moving Obstacles a ( y b + b {( b + ( yb } yi k v k m ( bk + ( yb k= 1 a ( y bk + bk{( bk + ( yb } + v ( bk + ( yb g g

12 Gap between Ocean Modeling and UUV Path Planning Ocean Modeling Near Real- Time Ocean Data Analy?cal (ar?ficial: Poten?al (φ Stream Func?on (ψ UUV Path Planning

13 Poten?al and Streamfunc?on from Navy Ocean Model 3D Flow Decomposi?on u = +, v= + y z y z ψ ϕ ψ ϕ Ocean Modeling Near Real- Time (u, v, w Near Real- Time (φ, ψ v u y ψ =, ϕ = w UUV Path Planning

14 Ocean Modeling ObservaJons Global Regional Coastal 3D, Full Physics, Data Assimila.ng, Dynamic, Forecast Models US- East NCOM Groton NCOM Groton DelU3D Global NCOM NOGAPS COAMPS US- East NCOM Global NCOM Page 14

15 Navy Coastal Ocean Models (NCOM Same structure / algorithms as GNCOM Boundary Conditions provided by GNCOM FNMOC COAMPS forcing 3D Forecasts T, S, Currents, Elevation Resolution varies (~1 / 36 deg 55 vertical layers Forecast to 7/96 3hr increments Assimilates data from Satellites (SST, SSH insitu obs (XBTs, CTDs, floats, buoys First - East China Sea (ECS NCOM operational MAR08 Replaced MODAS for ASW support Implement 3-4 regions/year Eventual transition to COAMPS-OS (coupled atmosphere ocean waves American Seas R-NCOM 96-Hr Series Surface Temperature Surface Salinity Surface Elevation Surface Currents, Regional: 1/36 deg (3 km / 1.7 nm Coastal: 50 to 300 m

16 Lagrangian Drift Forecast Eamples from AMSEAS-NCOM 30 Day Period Start with OR&R surface oil coverage in the northern Gulf on 1 June. 30-day Drift uses daily 00Z analyses. No dissipation or wind effects (other than on currents. Material object drift starting with a line of particles from MS mouth to center of the Loop Current. 30-day persistence forecast using mean currents from 9June10 forecast series. Material object drift at 1000m (3300ft starting with a 1-degree disk at the wellhead. 30-day currents from daily 00Z analyses.

17 Eample Hampton Roads Inlet Within 3nm of Norfolk Naval Base Hampton Roads- world s leading bulk cargo harbor. 150, ,000 barrels of petroleum in and around Hampton Roads biweekly Si military tankers (7.5 million gallon capaciity homeported in Norfolk

18 Bathymetry for Hampton Roads Inlet

19 High- Resolu?on NAVO Ocean Model (Delj 3D

20 Summary Navy tac?cal ocean environmental models and data are very important and useful for the CRUSER program. We will con?nue our efforts to effec?vely incorporated the ocean models in the UUV opera?ons.