In astronomical surveying, what is the difference in the apparent position of a celestial body when viewed from the earth’s center compared to the observer's location known as?

In astronomical surveying, the difference in the apparent position of a celestial body when viewed from the Earth's center compared to an observer's specific location is referred to as parallax. Parallax occurs due to the change in perspective when an observer is at two different points—in this case, the center of the Earth and the observer's location on the Earth's surface. This phenomenon allows surveyors to calculate the positions of celestial bodies more accurately by taking into account the observer's specific point of view.

Refraction pertains to the bending of light as it passes through different media, influencing the apparent position of celestial objects but not directly related to the observer's specific location. Right Ascension and Declination are celestial coordinates used to define the position of objects in the sky, akin to latitude and longitude on Earth, but they do not address the difference in perspective caused by the observer's location versus the center of the Earth.