Normalized Carrington maps (same as Fig. 2) at 2.5 R_⊙ for CR 2091 from STB, SOHO, and STA, aligned to a common reference time. The blue box indicates the parts of the maps observed within ±2 days from the center date of CR 2091. By collating these six boxes (starting from STB east and ending with STA west), we can obtain a near-synchronic (to within about five days) map of the entire corona.