LA Land Surveyor key terms

A physical object such as a pipe, tag, or stake described in a recorded map or deed that marks a boundary corner. It controls over distances and bearings when original and undisturbed.

Physical traces of an original survey corner, including the monument itself, its remains, pits, mounds, or accessories. Evidence is weighed by reliability, with undisturbed original monuments ranking highest.

A retracement method that restores a lost corner position by distributing record distances along the line between found corners, used mainly for lost corners of the public land survey system.

The first federal survey establishing section, township, and range lines and setting original monuments. Its positions and monuments control later retracements and subdivision of the public lands.

The rectangular system grid of the public land survey: a township is nominally six miles square containing 36 sections, and ranges are numbered east or west from a principal meridian.

A doctrine allowing a person who uses another's land openly, notoriously, exclusively, and continuously for the statutory period to gain title. California's period is generally five years with payment of taxes.

A right to use another's land acquired through open, notorious, adverse, and continuous use for the statutory period, without exclusivity or tax payment. It grants use rights, not ownership.

An agreement between adjoining owners fixing an uncertain boundary line. When the location is genuinely uncertain and the parties agree and act on it, the agreed line binds them and later buyers.

A nonpossessory right to use another's land for a specific purpose, such as access or utilities. It may be appurtenant to a parcel or in gross to a person or entity.

The degree of care and skill a reasonably competent licensed surveyor would exercise under similar circumstances. Expert testimony usually establishes it in negligence claims against surveyors.

A declaration by a licensed surveyor filed with a complaint alleging professional negligence, stating that the case has merit. California requires it before suing a surveyor for negligence.

A map filed with the county surveyor showing a survey that establishes or reestablishes boundaries, discloses evidence, and identifies discrepancies. California law specifies when filing is required.

The North American Datum of 1983, a geocentric reference frame realized through a network of control stations. It replaced NAD27 and is expressed in state plane and other projected systems.

A system of projected coordinate zones, each with a defined map projection and constants, used to express positions on a plane with low distortion. California uses multiple Lambert zones.

A mathematical transformation from positions on the curved earth to a flat plane. Common forms include Lambert conformal conic and transverse Mercator, each distorting distance, area, or direction.

The ratio between a distance on a projection or grid and the corresponding distance on the reference ellipsoid. Combining grid and elevation factors converts ground distances to grid distances.

The equipotential surface of the earth's gravity field approximating mean sea level. Orthometric heights are measured relative to it, and the geoid-ellipsoid separation relates GNSS heights to elevations.

An electronic instrument combining an electronic theodolite with an electronic distance meter. It measures horizontal and vertical angles and slope distances and computes coordinates and elevations.

A survey in which a series of connected lines with measured lengths and angles establishes positions of points. Closed traverses allow checks of angular and linear misclosure.

A method of determining an instrument station's coordinates by observing known points from that unknown station. It is the inverse of setting up over a known point and backsighting.

A statistical method that distributes random errors among redundant observations by minimizing the sum of squared residuals, providing adjusted coordinates and estimated precisions.

The difference between a measured quantity and its expected value in a closed survey, such as the gap between starting and ending coordinates. It is compared to an allowable tolerance.

The science of obtaining reliable measurements and spatial information from photographs or other imagery. It includes aerial, terrestrial, and close-range methods and produces maps and models.

An aerial image geometrically corrected so that scale is uniform and terrain displacement is removed, functioning as a map. It is commonly used as a base layer in mapping and GIS.

A point with known coordinates or elevation, visible in imagery or on the ground, used to georeference and orient photogrammetric models or remote sensing products.

A gridded representation of terrain elevations, often derived from lidar or photogrammetry. It supports contour generation, slope analysis, and hydrologic modeling in mapping and GIS.

A remote sensing technology that measures distances by timing laser pulses reflected from surfaces. It produces dense point clouds useful for terrain models, vegetation, and building extraction.

A line on a map connecting points of equal elevation. Contour interval, index contours, and hachures convey terrain shape and steepness to map readers.

The ratio between a distance on a map and the corresponding distance on the ground, expressed as a representative fraction, graphic bar, or verbal statement.

A map submitted for approval showing a proposed subdivision's design, improvements, and compliance with local ordinances. Approval precedes preparation and recording of a final or parcel map.

A subdivision map prepared after tentative map approval and conditions are satisfied, then approved and recorded. It legally creates lots and must conform to the Subdivision Map Act.

A map used for subdivisions of four or fewer parcels, or certain lot line adjustments, that is approved and recorded under the Subdivision Map Act in place of a final map.

California's statutory framework governing the design, approval, and recording of subdivision maps. It delegates regulation to local agencies and sets statewide requirements and procedures.

The process of placing stakes or marks on the ground at positions and elevations specified by construction plans, so that improvements can be built in the correct location.

A stable monument or point with a known elevation or coordinates, used as a reference for vertical or horizontal control in surveys and construction.

A survey documenting the actual location and elevation of constructed improvements after or during construction, used to verify compliance with plans and record final conditions.

A structured collection of spatial data stored with defined feature classes, relationships, and rules. It supports topology, attribute validation, and editing workflows in GIS.

Rules describing spatial relationships such as adjacency, connectivity, and containment among features. In GIS it enforces data integrity and supports network and overlay analysis.

A reference framework defining how positions are expressed as numbers, including datum, projection, and units. Correct definition is essential for aligning GIS layers and survey data.