TY - CPAPER AU - B. Farrell AU - P.J. Ioannou BT - Seminar on Predictability of weather and climate, 9-13 September 2002 CY - Shinfield Park, Reading DA - 2003 LA - eng PB - ECMWF PP - Shinfield Park, Reading PY - 2003 SP - 35 EP - 40 T2 - Seminar on Predictability of weather and climate, 9-13 September 2002 TI - Optimal state estimation using balanced truncation. ER -