Fig. 4 Eigen ray diagram of 1-2 measurement line.
Fig. 5 Ray identify. Upside shows calculation and downside shows observation.
This cruise consisted of two part (Leg1 and Leg2). Leg1 is called deployment cruise and main purpose was deployment of five sets of tomography transceivers. Leg2 is called ocean observation cruise and main purpose was measure the physical amount of the ocean using CTD, XCTD and XBT. ADCP measurement were continued almost all times in this cruise. The schedule of this cruise and observation is shown to the Table 1.
3. Preliminary result of this experiment
For the analysis of this data, calculate sound speed profile from NODC data and observation data in this cruise using Del Glosso equation. The NODC data in this area is 185 points and CTD and XCTD observation in this cruise is 60 points. Reference sound speed C0 was averaged profile of these all data and EOFs were calculated from this data.
Preliminary result is analyzed temperature profile of 1-2 measurement line (between No. 1 and No. 2 transceivers) and compared with CTD measurement. The horizontal range of 1-2 line is 1138.8km. Ray diagram of this line is shown Fig. 4. Propagation data was compared with ray trace and identified. Fig. 5 shows identified rays and 22 rays were used to this analysis. For inverse problem, stochastic inverse method was used. 8 modes of EOFs were used for vertical and horizontal is not divided (average of horizontal range). Observation matrix was made by all observation data. To determine noise variances, a follow calculate was done. Make a sound speed profile from averaged CTD and XCTD observation of 1-2 line. This profile calls C12. C12 is different from C0. Calculate ray trace using C0 and C12. The different of these travel time shows asterisk of left side of Fig. 6. Black dots of this Figure is calculated from δC (=C12 - C0) and probability value of inversion. The difference of these travel time (right side of Fig. 6) means inversion error of this analysis and the rms of this value is about 14 msec. The noise variances was used 20 msec consider with another measurement errors.
One of the result is shown Fig. 7. Broken line shows CTD observation difference from C0 and solid line shows tomography result using 17-Jan. and 22-Jan data. CTD observation is in the error bar of tomography result. This shows certainly of this analysis.
