Convert Rod (US Survey) (rd (US)) to Earth's Polar Radius (R⊕ (p)) instantly.
About these units
Rod (US Survey) (rd (US))
The US Survey Rod equals 16.5 US Survey Feet (~5.0292 meters). Like the chain and furlong, it serves as a subdivision of larger units, maintaining consistency with historic Gunter-based measurements. Surveyors historically used rods to measure short distances, delineate boundaries, and calculate acreages. Its simple relationship to chains and furlongs made it practical for field measurements without complex arithmetic. Today, the US survey rod primarily appears in historical records, legal surveys, and when referencing pre-metric property data, providing continuity between older and modern surveying conventions.
Earth's Polar Radius (R⊕ (p))
The Earth's polar radius is approximately 6,356.8 km, slightly shorter than the equatorial radius due to the Earth's flattening at the poles. This measurement is critical in modeling Earth's shape, gravity field, and rotation. It impacts satellite orbits, geodetic surveys, and global positioning systems (GPS). The difference between the equatorial and polar radii also explains phenomena such as centrifugal force variations, equatorial bulges, and sea level differences across latitudes. Understanding R⊕ (p) is essential for precision navigation, Earth science, and astronomy.