GA Land Surveyor cheat sheet

Curvature and refraction combined correction: C = 0.0206·(D² in meters) when D is in kilometers squared form 0.0675K²; refraction bends sights toward the earth, so combined correction is subtracted from rod readings for leveling.

Earth curvature drop formula: h = 0.0231·K² (h in meters, K in kilometers); refraction alone is about 1/7 of curvature, so combined effect ≈ 0.0206·K².

Horizontal distance from slope distance: H = S·cos(vertical angle) when the vertical angle is measured from the horizontal; slope correction = S − S·cos(θ).

Traverse closure: linear error of closure = √(ΔE² + ΔN²); relative precision = closure error ÷ total traverse length, expressed as 1:N.

Latitude and departure: latitude = distance·cos(azimuth), departure = distance·sin(azimuth); sum of latitudes and departures around a closed traverse should equal zero.

Azimuth to bearing conversion: NE quadrant bearing = azimuth; SE = 180° − azimuth; SW = azimuth − 180°; NW = 360° − azimuth.

Compass rule (Bowditch) distributes closure error proportionally to traverse leg length: correction to latitude = −(total latitude error)·(leg length ÷ total length).

Area by coordinates (shoelace): 2A = Σ(Xᵢ·Yᵢ₊₁ − Xᵢ₊₁·Yᵢ), taking the absolute value and dividing by 2; coordinates must be in a consistent order around the boundary.

Differential leveling: elevation difference = backsight − foresight; elevation of a point = height of instrument − foresight, where HI = known elevation + backsight.

Minimum angular closure for a closed traverse is commonly tested as a·√n where a is the instrument's stated accuracy and n is the number of angles; compare the actual misclosure against this value.

Allowable level-loop misclosure is often specified as a constant times √(loop length in miles or kilometers); the constant depends on the order of survey (e.g., 0.05 ft·√mi for third-order work).

A boundary survey that retraces an existing description is governed by the order of evidence: natural monuments, artificial monuments, distances, then area or quantity.

Adverse possession generally requires actual, open and notorious, exclusive, hostile, and continuous possession for the statutory period; surveying records may be used to prove or refute these elements.

Record-retention and seal rules: surveys must be signed and sealed by the licensed land surveyor in responsible charge, and field notes and plats are typically retained for a period set by state statute.

Professional liability exposure: standard of care is that of a reasonably prudent surveyor in the same locality; errors and omissions insurance covers negligence claims but not intentional misconduct.

Conflict of interest and disclosure: a surveyor must disclose any financial interest in the property being surveyed and may not accept compensation from multiple parties for the same survey without disclosure.

Statutes of limitations for survey negligence vary by state and may run from the date of the survey or from discovery of the error; the discovery rule often extends the period.

Ethical duty: a surveyor who discovers an error in a prior survey should notify the affected parties and correct the record rather than conceal the discrepancy.