What area of science was Sisir Kumar Mitra known for researching extensively?

Answer

Radio physics and the ionosphere

Mitra dedicated a substantial part of his scientific life to researching atmospheric physics, specifically the upper layers of the Earth’s atmosphere often referred to as the ionosphere, and radio wave propagation.

What area of science was Sisir Kumar Mitra known for researching extensively?
nameSpacecraterastronomysolar system