Standard Surveying Terms

  • Aliquot - The description of fractional section ownership used in the U.S. public land states. A parcel is generally identified by its section, township, and range. The aliquot specifies its precise location within the section, for example, the northwest quarter of the southeast quarter.
  • Azimuth - The number of degrees from north (or other reference direction) that a line runs, measured clockwise.
  • Baseline - In the U.S. Public land surveying system, a surveyed east-west (i.e. latitudinal) reference line, often hundreds of miles in length, from which tiers of townships are are surveyed to the north and south. There are approximately two dozen baselines in the lower 48 states. See also meridian.
  • Bearing - See azimuth. Bearings taken with a compass will be referenced to magnetic north unless otherwise noted.
  • Benchmark - A survey mark made on a monument having a known location and elevation, serving as a reference point for surveying.
  • Call - Any feature, landmark, or measurement called out in a survey. For example, "two white oaks next to the creek" is a call.
  • Chain carrier - An assistant to the surveyor, the chain carriers moved the surveying chain from one location to another under the direction of the surveyor. This was a position of some responsibility, and the chain carriers took an oath as "sworn chain carriers" that they would do their job properly.
  • Chord - The straight line connecting the end points of an arc.
  • Condition - See Conditional line.
  • Conditional line - An agreed line between neighbors that has not been surveyed, or which has been surveyed but not granted.
  • Corner - The beginning or end point of any survey line. The term corner does not imply the property was in any way square.
  • Declination - The difference between magnetic north and geographic (true) north. Surveyors used a compass to determine the direction of survey lines. Compasses point to magnetic north, rather than true north. This declination error is measured in degrees, and can range from a few degrees to ten degrees or more. Surveyors may have been instructed to correct their surveys by a particular declination value. The value of declination at any point on the earth is constantly changing because the location of magnetic north is drifting.
  • First station - See Point of Beginning
  • Gore - A thin triangular piece of land, the boundaries of which are defined by surveys of adjacent properties. Loosely, an overlap or gap between properties. See also strip.
  • Landmark - A survey mark made on a \'permanent\' feature of the land such as a tree, pile of stones, etc.
  • Line Tree - Any tree that is on a property line, specifically one that is also a corner to another property.
  • Merestone - A stone that marks a boundary. See monument.
  • Meridian - In the U.S. public land surveying system, a surveyed north-south (i.e. longitudinal) reference line, often hundrends of miles in length, from which ranges are surveyed to the east and west. There are approximately two dozen meridians in the lower 48 states. See also baseline.
  • Mete - A limit point or mark. To butt up against.
  • Metes and Bounds - An ancient surveying system that describes a parcel of land in terms of its relationship to natural features and adjacent parcels.
  • Monument - A permanently placed survey marker such as a stone shaft sunk into the ground.
  • Point of Beginning - The starting point of the survey
  • Plat - A drawing of a parcel of land.
  • Range - In the U.S. public land surveying system, a north-south column of townships, identified as being east or west of a reference longitudinal meridian, for example, Range 3 West. See township.
  • Searles Spiral - A surveying technique used by railroad surveyors in the the late 1800s and early 1900s whereby they approximate a spiral by use of multiple curved segments.
  • Section - In the U.S. public land surveying system, an area one mile square. See aliquot.
  • Strip - A rectangular piece of land adjoining a parcel, created when a resurvey turns up a tiny bit larger than the original survey. The difference is accounted for by temperature or other effects on measuring chains. See also gore.
  • Tangent line - A line that touches a circle at exactly one point and which makes a right angle with the circle\'s radius. For example, a circle that fills a square has four tangent points and the square\'s sides are tangent lines. An arc (curve) in a survey is part of a larger circle. One can construct tangent lines at the end points of the arc.
  • Tie line - A survey line that connects a point to other surveyed lines.
  • Tier - In the U.S. public land surveying system, an east-west row of townships identified as being north or south of a latitudinal baseline.
  • Total station - A survey instrument that combines a theodolite and distance meter.
  • Township - In the U.S. public land surveying system, an area six miles square, containing 36 sections. The townships are organized in tiers and ranges, identified with respect to a baseline and meridian. For example, Township 13 North Range 6 West describes a township\'s location.
  • Traverse - 1) any line surveyed across a parcel, 2) a series of such lines connecting a number of points, often used as a base for triangulation.
  • Trocha - Spanish for \'path\'. In the southeast U.S. it is used for a cut or cleared survey line.
  • Witness Tree - Generally used in the U.S. public land states, this refers to the trees close to a section corner. The surveyor blazed them and noted their position relative to the corner in his notebook. Witness trees are used as evidence for the corner location.