What would affect your measurement of a moving object's velocity?

The measurement of a moving object's velocity is dependent on the reference frame from which you are measuring. A moving reference frame is one that is also in motion relative to the object being observed. When you measure velocity from this type of frame, the measurement accounts for both the speed of the observer and the speed of the object. As a result, the perceived velocity of the moving object can change and may appear larger or smaller than it actually is, depending on the direction and speed of both the observer and the object.

In contrast, when measuring from a static or fixed reference frame, or a non-moving reference frame, the velocity of the object is measured without the influence of another moving frame. Here, the velocity can be measured accurately with respect to a stationary point, eliminating the complications introduced by relative motion. Therefore, using a moving reference frame can significantly affect the measurement of an object's velocity.