NJ Land Surveyor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Traverse angular closure

For a closed polygon traverse with n angles, the sum of interior angles should equal (n − 2) × 180 degrees; the difference from the observed sum is the angular misclosure.

Latitude and departure

Latitude equals distance times cosine of azimuth; departure equals distance times sine of azimuth. Summing them around a closed traverse should yield zero for each component.

Compass rule

A traverse adjustment method that distributes latitude and departure misclosures proportionally to course length; also called the Bowditch rule.

Relative precision

Linear misclosure divided by total traverse length, expressed as a ratio such as 1:10,000; it indicates the accuracy of the traverse.

Degree of curve

The central angle subtended by a 100-foot arc (arc definition); radius equals 5729.58 divided by the degree of curve.

Tangent distance

For a circular curve, T equals R times tangent of Δ/2, where R is radius and Δ is the central intersection angle.

Middle ordinate

The distance from the midpoint of a circular curve to the midpoint of its long chord; M equals R times [1 − cos(Δ/2)].

Differential leveling

Elevation difference between two points equals backsight minus foresight. Repeated setups accumulate elevation changes and are checked against known benchmarks.

Curvature and refraction

For leveling and trigonometric leveling, the combined correction is approximately 0.0206 × D² feet with D in thousands of feet, applied with refraction coefficient about 0.13.

Area by coordinates

The shoelace formula: twice the area equals the sum of Xi·Yi+1 minus Xi+1·Yi around the closed traverse, with coordinates taken in order.

Elevation factor

The ratio R/(R + h) used to reduce ground distances to the ellipsoid; R is Earth radius and h is ellipsoid height above the reference surface.

Grid scale factor

The ratio of grid distance to ellipsoid distance at a point in a state plane projection; combined with elevation factor it converts ground distance to grid distance.

Standard error of mean

The standard deviation of a set of observations divided by the square root of the number of observations; it estimates the uncertainty of the mean.

Azimuth versus bearing

Azimuth is measured clockwise from north, from 0 to 360 degrees; bearing is measured from north or south toward east or west, from 0 to 90 degrees.

Horizontal curve length

Arc length equals R times Δ in radians, or 100 times Δ divided by the degree of curve when using the arc definition.

Vertical curve formula

For a parabolic vertical curve, elevation equals PVC elevation plus g1·x plus (g2 − g1)·x²/(2L), where x is distance from the PVC.

ALTA/NSPS survey

A land title survey meeting national standards that shows title boundaries, easements, improvements, and optional Table A items selected in writing by the client.

Order of calls

In boundary retracement, natural monuments control over artificial monuments, which control over courses and distances, which control over area.

Adverse possession elements

Actual, open, notorious, exclusive, hostile, and continuous possession for the statutory period; all elements must be present to acquire title.

Riparian boundary rule

For non-tidal navigable waters the boundary is the ordinary high water mark; for tidal waters it is generally the mean high water line.

Accretion versus avulsion

Accretion is gradual and imperceptible deposit of land, which changes the boundary; avulsion is a sudden change, which does not move the boundary.

NAD83 and NAVD88

NAD83 (2011) is the current horizontal datum realization in the United States; NAVD88 is the vertical datum based on orthometric heights.

State plane coordinates

A projected coordinate system with zones and scale factors; ground distances must be converted using elevation and scale factors before computing grid coordinates.

RTK positioning

Real-time kinematic GNSS uses a base station or network correction to achieve centimeter-level accuracy; at least five satellites and good PDOP are recommended.

PDOP

Position dilution of precision measures satellite geometry strength; lower values indicate better geometry and more reliable positions.

Geoid model

A model of the geoid used to convert GNSS ellipsoid heights to orthometric heights above the vertical datum.

Standard of care

The degree of care and skill that a reasonably prudent surveyor would exercise under similar circumstances; it defines professional negligence.

Plat content requirements

A subdivision plat typically shows bearings, distances, curve data, monument ties, dedications, and the surveyor's certification and seal as required by statute.

Construction staking offsets

Stakes set at a specified distance from the design line to allow construction; cut or fill is noted relative to design grade.

Boundary evidence hierarchy

Courts give greatest weight to natural monuments, then artificial monuments, then courses and distances, and least weight to area when resolving boundary disputes.

Prescriptive easement

A right acquired by open, continuous, adverse use of another's land for the statutory period; unlike adverse possession, exclusivity is not required.

Table A items

Optional ALTA/NSPS survey items selected by the client in writing, such as utilities, flood zone, or zoning information, that must be shown on the survey.