What is the standard reference level to use in physics when measuring Gravitational Potential Energy (GPE)?

Hint: The energy accumulated in an object as a consequence of its vertical location or height is known as gravitational potential energy. The energy is stored as a consequence of the object's gravitational pull to the Earth.

Complete answer:
It would be interesting to understand what the projectile's kinetic energy is at the point where it falls in the case of simple projectile motion measurements. Any of the calculations becomes a bit smoother as a result of this, \[U = mgh\] , where $h$ represents the height above the landing point, $U$ is the potential energy at optimum height. When the projectile arrives at $h = 0$ , you can use this to measure the kinetic energy.

The standard reference level to use in physics when measuring Gravitational Potential Energy (GPE) is to use the centre of mass of each object when measuring orbital motions of planets, stars, and satellites. To measure the potential energy of the earth-moon system, for example, use the following equation:
$U = \dfrac{{G{m_{earth}}{m_{moon}}}}{r}$
Where $G$ denotes the universal gravitational constant, $m$ denotes the masses of the planet earth and moon, and $r$ denotes the distance between the earth and moon's centres.

For objects falling to the ground, this calculation is always right, but understanding the potential energy of something falling to the earth's core isn't really valuable knowledge.Knowing that you are about $4000$ miles from the middle of the planet would not help you understand the motion of a baseball.

Note: The height of an object in relation to a reference point, its mass, and the power of the gravitational field it is in all of these impacts its gravitational potential energy.The most common example that can help you understand the concept of gravitational potential energy is if you take two pencils. One is placed at the table and the other is held above the table. Now, we can state that the pencil which is high will have greater gravitational potential energy than the pencil that is at the table.