The gravitational force between two points near each other on Earth is not significantly different. However, the force of gravity does vary slightly depending on the distance from the center of the Earth and the distribution of mass within it. This variation in gravity is referred to as gravitational anomalies.
Satellites orbit around the Earth due to a balance between the gravitational force pulling them toward the Earth and their tangential velocity, which gives them the necessary centripetal force to maintain a stable orbit. Satellites are essentially in a state of continuous free fall, constantly falling toward the Earth but also moving forward fast enough to keep missing it. This dynamic equilibrium between gravity and velocity allows satellites to maintain a stable orbit.
Even though the gravitational force decreases with distance from the center of the Earth, satellites in orbit are still subject to the gravitational pull of the Earth. The force of gravity decreases with the square of the distance, so as satellites move farther from the Earth's surface, the force of gravity weakens but is still present.
It's important to note that while the force of gravity may vary slightly depending on the location on Earth, these differences are typically small and don't significantly affect the orbits of satellites. The primary factors affecting satellite orbits are their initial velocities, altitudes, and the mass distribution of the Earth.