Yes, the speed of light has been measured relative to the Earth and within various experimental setups. The most well-known and precise measurements of the speed of light have been conducted in laboratory settings using a variety of techniques.
One of the earliest successful measurements was performed in the 17th century by Danish astronomer Ole Rømer. He observed the moons of Jupiter and noted that their eclipses appeared to be delayed when the Earth was moving away from Jupiter and accelerated when the Earth was moving towards Jupiter. From these observations, he was able to estimate the speed of light to be approximately 225,000 kilometers per second, which is relatively close to the currently accepted value.
Over time, more accurate and sophisticated experiments have been conducted, refining the measurement of the speed of light. In the late 19th and early 20th centuries, experiments involving rotating toothed wheels and rapidly oscillating mirrors were used to measure the speed of light.
In 1983, the General Conference on Weights and Measures defined the speed of light in a vacuum to be exactly 299,792,458 meters per second (approximately 299,792 kilometers per second). This definition ties the speed of light to the meter and second, both of which are defined in terms of fundamental constants of nature.
Modern techniques to measure the speed of light include using lasers and extremely precise timing methods. These experiments are conducted in laboratories and are independent of the Earth's motion.
It's important to note that the speed of light in a vacuum is constant and does not depend on the motion of the observer or the source of light. This is a fundamental principle of Einstein's theory of special relativity, which has been confirmed by numerous experiments and observations.