The term 'sun altitude' specifically refers to the angle of the Sun above the horizon, typically expressed as a value between 0 and 90 degrees. This measurement is crucial in geographic information science as it influences various phenomena, including solar radiation intensity, shadow lengths, and the overall illumination of the Earth’s surface. When the sun is at 0 degrees, it is exactly on the horizon, while at 90 degrees, the sun is directly overhead. Understanding sun altitude is important for applications such as solar energy assessment, agricultural planning, and environmental modeling.
The other options do not accurately represent the concept of sun altitude. The angle of the Earth's rotation, while relevant in understanding solar position over time, is not related to sun altitude directly. Similarly, angles related to geological formations typically involve spatial analysis not connected with sun altitude. Lastly, atmospheric pressure measurements are completely distinct and unrelated to solar positioning. This reinforces why the first choice accurately encompasses the definition of sun altitude in the context of geographic information science.