I'm writing some software which can plot boundaries, similar to the resolution of the 'Coastline paradox'. I have aesthetic solutions for borders over land with variable lengths for straight runs, but was curious if there is some legal pretense or political convention which determines how precisely various types of boundaries (property, county, province, state, national, ...) are measured IRL.
Many boundaries are defined using:
- Latitude (in degrees, minutes, seconds) north or south of the equator
- Longitude (in degrees, minutes, seconds) east or west of a prime meridian (such as through the Greenwich Observatory)
- A reference geoid or ellipsoid (such as NAD 83), or the use of local surveying relative to mountains or stars.
Sometimes the boundary is clarified by using a map projection (that is based on a reference ellipsoid like NAD 83 and a UTM zone definition), with units in feet or meters relative to the origin of the zone. For example, the U.S. Supreme Court ratified such an ocean boundary (measured in meters, with a precision of 1 millimeter) between the United States and California. Most of the ruling is a data dump from a GIS system.
In many U.S. states, property boundaries are defined using chains of offsets. Each offset is measured in feet (often to a precision of 0.01 feet), with an angle in degrees, minutes, and seconds.