In situ measurement involves conducting measurements and observations directly in the natural environment or real-world setting where the phenomenon of interest occurs. This approach allows researchers to obtain accurate and real-time data without having to rely on laboratory simulations or controlled conditions. In situ measurement is commonly used in fields such as environmental science, ecology, geology, and oceanography to study various natural processes, including weather patterns, ecosystem dynamics, and geological formations. By collecting data in situ, researchers can better understand the complexity and interactions of systems in their natural state, leading to more informed decision-making and effective management strategies.