Acheson , D. J. 1990 . Elementary Fluid Dynamics . Clarendon Press , Oxford , 397 pp .
Aref , H., 1983 . Integrable, Chaotic and Turbulent Vortex Motion in Two-Dimensional Flows . Ann. Rev. Fluid Mech . 15 , 345 – 389 .
Gelb , A. 1974 . Applied Optimal Estimation . MIT Press , Cambridge , MA , 374 pp .
Hermann , R. and Krener , A. J. 1977 . Nonlinear Controllability and Observability. IEEE, Trans. Auto. Control 22 , 728 - 740 .
Ide , K. and Ghil , M. 1997a . Extended Kalman Filtering for Vortex Sys-tems. Part I: Methodology and Point Vortices . Dyn. Atmos. Oceans 27 , 301 – 332 .
Ide , K. and Ghil , M. 1997b . Extended Kalman Filtering for Vortex Systems. Part H: Rankine Vortices . Dyn. Atmos. Oceans 7 , 333 – 350 .
Ide , K. , Kuznetsov , L. and Jones , C. K. R. T. 2002 . Lagrangian Data Assimilation for Point Vortex Systems. J. Turbulence 3 , available online at http://www.tandf.co.uk/journals/titles/14685248.asp.
Krener , A. J. 2002 . The Convergence of the Extended Kalman filter . In: Directions in Mathematical Systems Theory and Optimization (eds A. Rantzer and C. I. Byrnes ). Springer Verlag , Berlin , 173 – 182 .
Kuznetsov , L. , Ide , K. and Jones , C. K. R. T. 2003 . A Method for assimilation of Lagrangian data. Mon. Wea. Re v . 131 , 2247 – 2260 .