NV Land Surveyor key terms

A fixed reference surface, point, or set of values from which positions, elevations, or coordinates are measured. Horizontal and vertical datums are usually defined separately and must be consistent with the survey's intended accuracy.

A permanent, monumented point of known elevation used as a starting or check reference for leveling and vertical-control work. Benchmarks should be described, recoverable, and tied to a recognized vertical datum.

The equipotential surface of Earth's gravity field that approximates mean sea level and serves as the reference for orthometric heights. It is irregular and is modeled numerically rather than by a simple geometric shape.

A mathematically defined, smooth oblate spheroid used as the geometric reference surface for horizontal coordinates and ellipsoidal heights. Many regions adopt a best-fitting local ellipsoid rather than a single global model.

A position expressed on the ellipsoid, typically as latitude, longitude, and ellipsoidal height, or as state plane or other projected values derived from them. These coordinates are the basis for control networks and large-area mapping.

A system of projected coordinate zones designed so that grid distances stay close to ground distances within each zone. Each zone uses a defined projection, origin, and false easting and northing.

A mathematical transformation that converts positions on the curved ellipsoid to a flat grid, inevitably introducing distortion in distance, area, shape, or direction. Common families include transverse Mercator, Lambert conformal conic, and oblique Mercator.

The ratio between a distance on the projection grid and the corresponding distance on the ellipsoid or at ground level. Grid, elevation, and combined factors are often applied separately when converting between ground and grid distances.

The process of adjusting a measured ground distance to its projected grid equivalent by applying the elevation factor and the map scale factor. Failure to apply it can produce coordinate misclosures of many parts per million.

A horizontal direction measured clockwise from a specified reference meridian, usually true north or grid north, through 360 degrees. Azimuths are preferred over bearings in many computations because they avoid quadrant letters.

A horizontal direction stated as an acute angle from north or south toward east or west, such as N 45 E. Bearings must be converted to azimuths before many traverse and coordinate computations.

The north-south and east-west components of a course, computed as distance times the cosine and sine of its azimuth. Summing them around a closed traverse gives the misclosure in northing and easting.

A survey in which a series of connected courses is measured for direction and distance to determine coordinates of successive stations. Closed traverses return to a known point or known direction, allowing misclosure to be detected and adjusted.

The discrepancy between computed and known values at the end of a survey, such as the linear gap in a closed traverse or the elevation difference in a level loop. It is compared with an allowable tolerance before adjustment.

A traverse adjustment that distributes the north-south and east-west misclosures in proportion to course length, also called the compass rule. It is commonly applied to closed traverses of moderate precision where angular and linear errors are not separately modeled.

A method of determining elevation differences by reading a graduated rod at two points with a level instrument set between them. The difference of rod readings gives the elevation change, and loops are checked against known benchmarks.

A temporary point on which a rod is held while the instrument is moved to a new setup, preserving the elevation chain in leveling. The point must be stable and the rod reading taken before and after the move.

A leveling run that starts and ends on known or check elevations, allowing total closure error to be computed. Closure is compared with a tolerance based on distance or number of setups before the run is accepted or adjusted.

The error caused when a level's line of sight is not exactly horizontal, producing rod readings that increase with distance from the instrument. It is detected by a peg test and controlled by keeping foresight and backsight distances balanced.

Elevation measured above the geoid along the direction of gravity, the value typically shown on topographic maps and used for engineering drainage. It differs from ellipsoidal height by the geoid undulation at the location.

An electronic instrument combining an angle-measuring theodolite with an electronic distance meter and onboard data recording. It measures horizontal and vertical angles and slope distance to a target, from which coordinates are computed.

A technique that determines distance by timing or phase-comparing a modulated light or microwave signal traveling to a reflector and back. The measured slope distance is reduced to horizontal and vertical components using the vertical angle.

A fixed offset added to or subtracted from an EDM distance to account for the path length inside the prism assembly and instrument. The correct value depends on the manufacturer and must match the setting in the instrument.

An adjustment applied to EDM distances for the difference between actual air temperature and pressure and the values for which the instrument was calibrated. Ignoring it can bias long distances by several parts per million.

Global Navigation Satellite System positioning, including GPS and other constellations, which determines positions by ranging to satellites. Survey-grade results require careful observation, correction, and attention to multipath and satellite geometry.

Real-time kinematic GNSS positioning in which a base station or network sends corrections to a rover, yielding centimeter-level positions in the field. Accuracy depends on baseline length, satellite geometry, and radio or cellular link quality.

A point whose position is determined by traverse measurements and that typically carries a monument or mark for future use. Station descriptions and coordinates must be recorded so the point can be recovered and checked.

A physical object set to mark a survey point, such as a rebar, pipe, or concrete post, often with a cap identifying the surveyor. Monuments are the legal and practical evidence of boundary and control positions.

A point marking a boundary line terminus or change in direction, often established by an original government survey or a recorded plat. Corner evidence and its perpetuation are central to boundary retracement.

The process of reestablishing a boundary by locating and evaluating the original monuments and record evidence rather than simply following recorded bearings and distances. It is governed by rules of evidence and priority of calls.

The ranking of boundary evidence, generally placing natural monuments first, then artificial monuments, then courses and distances, and finally area or quantity. The rule helps resolve conflicts among recorded elements of a description.

A doctrine under which a person may acquire title to land through open, notorious, exclusive, hostile, and continuous possession for a statutory period. Surveyors should recognize its potential effect on boundary lines, though legal determination belongs to courts.

A right held by one party to use another's land for a specific purpose, such as access or utilities, without owning it. Easements may appear as encumbrances on a survey and must be located or noted when they affect the property.

The legal right to own, use, and transfer property, supported by deeds, records, and other evidence. A surveyor locates boundaries and improvements but does not render a legal opinion on title or ownership.

A written legal instrument that conveys an interest in real property and describes the land being transferred. The description may use metes and bounds, lot and block, or other calls that the surveyor must interpret and locate on the ground.

A recorded map showing parcels, boundary lines, monuments, and related information, often required before land can be sold or developed. Surveyors prepare plats to standards set by statute and local reviewing authorities.

The degree of care, skill, and diligence that a reasonably competent surveyor would exercise under similar circumstances. It is the benchmark for negligence claims and is shaped by professional standards, statutes, and accepted practice.

The professional stamp or seal applied to survey documents to certify that the work was performed by or under the responsible charge of a licensed surveyor. Its use is regulated by state law and carries legal accountability.

The principles of conduct governing professional practice, including competence, honesty, confidentiality, and avoidance of conflicts of interest. Licensing boards enforce minimum standards, and violations can lead to discipline.