Who are they?

• Amateur radio operators are known as radio amateurs or hams who use radio frequency spectrum  for purposes of non-commercial exchange of messages, wireless experimentation,  self-training, private recreation, radiosport, contesting, and emergency communication.
• HAM refers to the Amateur operators and not the radio itself.

Significance

• Amateur Radio operators are most likely to be active after disasters that damage regular lines of communications due to power outages and destruction of telephone, cellular and other infrastructure-dependent systems.
• The empowerment of local youth to operate the technology will help the State’s disaster preparedness and management.
  • Related law–  Indian Wireless Telegraphs (Amateur Service) Amendment Rules, 1984.
  • Any citizen of India who is above 12 years of age can become a ham by qualifying in the Amateurs Station Operators’ examination (ASO) and obtaining a valid Amateur wireless telegraph station license.

What are radio waves?

• Radio waves have the longest wavelengths in the electromagnetic spectrum. 
• Heinrich Hertz proved the existence of radio waves in the late 1880s.
• Radio-wave communications signals travel through the air in a straight line, reflect off of clouds or layers of the ionosphere, or are relayed by satellites in space.

Why in News:

• HAM radios are going to be deployed to aid in cyclone relief in the Sunderbans.

1. To read about types of Cyclones & its formations – https://officerspulse.com/cyclones/ 
2. To read about Cyclones in India- https://officerspulse.com/cyclone-yaas/ 

Reference:

1. https://www.thehindu.com/news/cities/kolkata/local-youth-to-be-trained-to-operate-ham-radios-in-disaster-prone-sunderbans/article35512071.ece