international definition of a foot
Consultants in the 3D industry who are not trained or are unfamiliar with surveying or geomatics systems may be surprised to learn that there are two different measurements for the length of a foot in the United States: the International Foot (also commonly called the foot) and the U.S. Survey Foot. The International Foot (which we were all taught in school) is defined as 0.3048 meters, whereas the U.S. Survey Foot is defined as 0.3048006096 meters. The difference of the two equates to 2 parts per million. For example, in a measurement of 10,000 feet, the difference would be 0.02 feet (just less than one-quarter of an inch).