By 14 March, cloud-free images from ALOS and other satellites were obtained for nearly all coastal areas, which comprised the first post-disaster data. These images allowed for local conditions to be directly and uniformly assessed across a broad region, and were the most frequently used geospatial results during the early response stages. Despite vast devastation, the following circumstances helped lead to a successful rapid response:
(1)
Many satellites from JAXA, the International Charter, Sentinel Asia, and others participated in the observation (see Table 1 and Table 2);
(2)
Affected areas were located along and within the path of the satellite (for example, refer to Fig. 3); and
(3)
Good weather allowed for clear observation of impacted areas.
5.2. Examining how general users employed satellite data
Based on the opinion survey for general users (see Section 1), whose results are summarised in Table 6a and 6b, the following analysis can be made.