Which type of radiation cannot be utilized by remote sensors?

The reasoning behind choosing gamma rays as the type of radiation that cannot be utilized by remote sensors relates to the characteristics of gamma radiation and its interaction with matter. Gamma rays possess extremely high energy and very short wavelengths, which allow them to penetrate most materials, including the Earth’s atmosphere. This penetration makes it challenging for remote sensing instruments to capture meaningful data from the Earth's surface or the atmosphere without interference.

Remote sensors are designed to detect various electromagnetic wavelengths, each suitable for different applications depending on their interaction with the environment. Infrared radiation can effectively sense thermal emissions from the Earth's surface, ultraviolent radiation can provide insights into atmospheric conditions and surface composition, and X-rays can be used in certain specialized applications, although less commonly than other forms. However, gamma rays are generally not used in remote sensing due to their high energy and the resultant safety concerns, as well as technical challenges in detecting and interpreting the signals they produce from terrestrial or atmospheric sources. Thus, rugged and sensitive detection equipment is required to utilize other types of radiation, while gamma rays remain impractically challenging.