Registered Surveyor key terms

A doctrine by which a person can acquire title to land by open, notorious, exclusive, hostile, and continuous occupation for a period set by statute, regardless of the record owner's wishes.

A boundary location doctrine holding that when neighbors treat a line as the true boundary for a long period, courts may enforce that line even if it differs from the deed description.

The doctrine that a long-accepted, mutually recognized monumented boundary line may control over a conflicting deed call, protecting settled expectations of adjoining owners and their successors.

A physical object, natural or artificial, that marks a boundary corner or line and is used as evidence of the original survey position; it usually outranks distance and direction calls.

A corner location where several surveyors have set multiple, slightly separated monuments, creating a cluster; resolving it requires weighing evidence and hierarchy of calls rather than simply choosing the newest mark.

The process of re-establishing an existing boundary by recovering and following the evidence of the original survey, rather than creating a new boundary or inventing new positions.

A method of restoring a lost corner by distributing the discrepancy between record and measured distances among the remaining original corners along the line, used mainly for lost interior corners.

A corner whose original position cannot be recovered from physical evidence or reliable testimony and must be re-established by accepted rules such as proportionate measurement or intersection of lines.

A reference framework defining the size, shape, and position of the Earth for coordinates, including an ellipsoid and its tie to the physical Earth, such as NAD83 or a modern terrestrial reference frame.

The equipotential surface of the Earth's gravity field that best approximates mean sea level, used as the reference for orthometric heights and separated from the ellipsoid by the geoid undulation.

Height of a point above the geoid, measured along the plumb line and commonly called elevation; it differs from ellipsoid height by the geoid undulation at that location.

Height of a point above the reference ellipsoid measured along the ellipsoid normal, also called geodetic height; GNSS typically delivers this value rather than orthometric elevation.

A system of projected plane coordinates established for each U.S. state, using one or more zones and a conformal projection, so that grid distances and directions stay close to ground values.

The ratio between a distance computed on a projected coordinate grid and the corresponding ellipsoid distance; it must be applied when converting between grid and ground measurements.

The ratio of a map or grid length to the corresponding ellipsoid length at a point, varying with position in most projections and central to converting between ground and grid distances.

A mathematical transformation that maps positions on the curved Earth onto a flat surface, inevitably introducing distortion in distance, area, shape, or direction that must be chosen for the intended use.

A projection that preserves local angles and shapes at every point, so that small circles remain circles and grid directions match true bearings; distance and area may still be distorted.

A conformal cylindrical projection wrapped around a meridian rather than the equator, widely used for state plane zones and national grids because distortion stays small near the central meridian.

An electronic instrument combining an electronic theodolite with an electronic distance meter and onboard computing, allowing angles and distances to be measured and coordinates computed at one setup.

Distance measurement by timing a modulated light or microwave signal traveling to a reflector or target and back, yielding slope distance that is reduced to horizontal and vertical components.

Adjustment applied to electronic distance measurements for air temperature, pressure, and humidity, since the speed of light in air differs from the instrument's reference conditions.

A fixed offset added to or subtracted from an electronic distance measurement to account for the path length inside a reflector or prism assembly and its mounting.

A survey in which a series of connected courses is measured for direction and distance to determine coordinates of successive stations, either closed or tied to known control.

The difference between a computed and a known value in a closed survey, such as a loop failing to return to its starting coordinate; it indicates accumulated random and systematic error.

A statistical method that distributes survey discrepancies among observations in proportion to their weights, minimizing the sum of squared residuals and yielding the most probable coordinate values.

A measure of the spread of repeated observations around their mean, equal to the square root of the variance; it is the basis for expressing survey precision and confidence intervals.

A gross, non-random mistake such as a misread value, wrong target, or transposed digits; unlike random error it cannot be reduced by averaging and must be detected and removed.

Real-time kinematic positioning, in which a rover receives carrier-phase corrections from a base station or network to compute centimeter-level coordinates in the field almost immediately.

An official, systematic register of land parcels showing ownership, boundaries, and often value or use, maintained by a government and tied to maps and parcel identifiers.

A land registration system in which the state guarantees title through a register, so that a registered owner's title is indefeasible and transfer does not require tracing a chain of deeds.

The chronological record of successive ownership transfers of a parcel, used in recording systems to establish that a seller holds valid title free of gaps.

A unique code, such as an assessor's parcel number, assigned to each land parcel so that maps, ownership records, and tax data can be reliably linked.

A digital polygon dataset representing land parcels with attributes and topology, used for mapping, analysis, and linking to the cadastral register; accuracy must be documented.

The set of rules describing spatial relationships such as adjacency, connectivity, and containment among features, independent of exact coordinates, enabling network and overlay analysis.

Two GIS data models: raster stores values in a regular grid of cells, suited to continuous surfaces like elevation, while vector stores points, lines, and polygons with precise coordinates.

A gridded representation of ground surface elevation, often derived from lidar or photogrammetry, used for terrain analysis, contours, and orthorectification of imagery.

Aerial or satellite image geometrically corrected for camera tilt and terrain relief so that it has a uniform scale and can be used as a map with measured positions.

The science of deriving measurements and three-dimensional positions of objects from overlapping photographs or imagery, using camera geometry and control points.

Light detection and ranging: a remote sensing method that fires laser pulses and times their return to produce dense three-dimensional point clouds of terrain, vegetation, and structures.

The professional obligation to explain a survey's scope, limitations, and likely accuracy to a client before work begins, so the client can make an informed decision about the services purchased.

The degree of skill, care, and diligence that a reasonably competent surveyor would exercise under similar circumstances, used to judge professional negligence.

A situation in which a surveyor's personal, financial, or other interest could improperly influence professional judgment; it must be disclosed and avoided or managed.