What is the formula for Critical Velocity of Satellite Orbiting at a height from the Earth’s Surface?

Critical velocity is the minimum velocity of projection for which satellite revolves in a circular orbit around the earth.

G = Universal Gravitational Constant

g_h = acceleration due to gravity at height h above earth’s surface

M= Mass of the earth

R =Radius of the earth

h = height at which satellite is orbiting

If satellite is revolving very close to the earth’s surface, then

So V_c= √ g_h(R+h) is the formula for Critical Velocity of Satellite Orbiting at height h from the Earth’s Surface