Geodetic surveying, or surveying for short, is the second oldest profession in civilization. Geodetic surveying is the science of measuring the Earth. The Pharaohs of Egypt employed surveyors called harpedonapata to measure and divide the land using simple geometry.
These surveyors tied knots in ropes at certain intervals to gauge distance. They formed right angles by tying two knots on a length of rope and stretched that rope into a triangle with the knots at two corners.
The Greeks contributed calculations about the shape and circumference of the planet. They are also credited with inventing the astrolabe for more accurate triangulation, measuring the widths of rivers, and other applications. The Roman hierarchy established surveying as a profession primarily for tax enforcement and improved surveying with hydrological principles.
Arabic surveyors in the time of the Caliphate are responsible for vast improvements to the profession. Their notable inventions include advanced leveling tools, the rotating alidade for accurate alignment, and vast improvements to the Greek astrolabe for stellar navigation.
Geodetics today uses the latest mathematical formulae and surveying instruments to measure our world, as did our ancestors. Technique and tool advancement incorporate the latest workable theories, technologies like Global Positioning Systems (GPS) and Geodetic Information Systems (GIS).
The latest paradigm for geodesy is shifting to spatial data collection and analysis due to the synthesis of photogrammetry, satellite navigation, and current surveying techniques. This new direction is known as geomatics or geospatial technology. Applications include rapid coastal mapping and disaster risk assessment.