Abstract
Japanese space weather research and operation began in 1896 with
research on radio propagation. LF, MF, and HF radio communication used
to be important before the era of communication satellites; however,
they are affected by ionospheric conditions and solar activity. A center
for the research and development of radio systems was established at
Hiraiso, which is now also a space weather observatory for measuring
solar activity, geomagnetic fields, and ionospheric conditions. The need
for space weather information initially decreased in the communication
satellite age, but since the beginning of the 21st century it has been
increasing again with the growing use of positioning satellite systems.
The role of Southeast Asian countries in space weather research has
become important and the range of activities is also growing. The
contribution of these countries to space weather research and operation
is expected to grow in future.