NJ Land Surveyor cheat sheet

Angular closure: sum of interior angles of a closed traverse = (n − 2) × 180°; compare observed sum to this value and distribute the misclosure equally (or by angle size) among the angles.

Latitude = distance × cos(azimuth); departure = distance × sin(azimuth). Linear misclosure = √(Σlat² + Σdep²); relative precision = misclosure ÷ total traverse length.

Compass rule (Bowditch): correction to a latitude or departure = −(total misclosure in that component) × (course length ÷ total traverse length). Transit rule distributes corrections proportional to the component magnitudes.

Curve formulas: R = 5729.58 ÷ D (degree of curve, arc definition); T = R tan(Δ/2); L = R·Δ(radians) = 100·Δ/D; M = R[1 − cos(Δ/2)]; external E = R[sec(Δ/2) − 1].

Differential leveling: ΔElev = backsight − foresight. Misclosure = observed elevation difference − known difference; permissible misclosure for a precise level run is commonly stated as C√M with M in miles and C = 0.02–0.05 ft.

Trigonometric leveling (short lines): ΔElev = S·sin(zenith angle) + (1 − k)·S²/(2R), where k ≈ 0.13 is refraction coefficient and R is Earth radius; correct for curvature and refraction.

State plane coordinates: grid distance = ground distance × (elevation factor) × (scale factor), where elevation factor ≈ R/(R + h). Ground-to-grid conversions are required before computing coordinates.

Area by coordinates (shoelace): 2A = Σ(Xi·Yi+1 − Xi+1·Yi) around the closed traverse; area by double meridian distances: double area = Σ(DMD × departure) for each course.

Error propagation: for a sum or difference, uncertainties add in quadrature; for a product or quotient, relative uncertainties add in quadrature. Standard error of the mean = s/√n.

ALTA/NSPS Land Title Survey: Table A optional items are selected by the client in writing; the surveyor must show easements, rights-of-way, and observed evidence of possession, and must state the basis of bearings and the date of fieldwork.

Horizontal/vertical datum: NAD83 (2011) is the current horizontal realization; NAVD88 is the vertical datum. State plane zone scale factors and combined factors must be reported when grid coordinates are shown.

Minimum standards for boundary retracement: follow the order of calls - natural monuments, artificial monuments, courses and distances, area; do not establish new lines where the original survey can be retraced.

Adverse possession requires actual, open, notorious, exclusive, hostile, and continuous possession for the statutory period; prescriptive easements require similar open and continuous use without exclusivity.

Riparian boundaries: for non-tidal navigable waters, the boundary is the ordinary high water mark; for tidal waters, the mean high water line is commonly used. Accretion belongs to the upland owner; avulsion does not move the boundary.

Subdivision plat review: check that the plat shows bearings and distances of all lines, curve data (R, L, Δ, chord, tangent), monument ties, dedications, and the surveyor's seal and certification per state statute.

Construction layout: compute cut/fill from design grades versus existing elevations; set offset stakes at the specified offset from the design line; verify control with a closed traverse before layout.

GPS/GNSS: use a minimum of 5 satellites for RTK; PDOP indicates geometric strength (lower is better). Network RTK requires a calibrated geoid model to convert ellipsoid heights to orthometric heights.

Professional liability: the standard of care is that of a reasonably prudent surveyor under similar circumstances; written contracts should define scope, deliverables, and limitations of the survey.