PS Surveying flashcards
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32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Negligence elements
- A surveyor is liable for negligence only when four elements are proven: a duty of care owed, a breach of that duty, causation of the loss, and actual damages.
- Standard of care
- The degree of care and skill ordinarily exercised by reputable surveyors practicing under similar conditions in the same or a similar locality.
- Common-law dedication
- Transfer of private land to public use that requires two elements: clear intent by the owner to dedicate and acceptance by the public or a governmental body.
- Statute of repose
- A statute that bars claims after a fixed period from the act or substantial completion of the work, regardless of when the injury or defect is discovered.
- Easement by necessity
- An implied easement created when a parcel is landlocked after severance of common ownership; it requires strict necessity and lasts only while the necessity exists.
- Seal and certification limits
- A licensee may seal and certify only surveying work personally performed or performed by subordinates under the licensee's direct supervisory control.
- Curvature and refraction correction
- Combined correction for leveling sights equals 0.0675 times K squared in meters, where K is sight distance in kilometers, or 0.0206 times F squared with F in thousands of feet.
- Geoid separation formula
- Orthometric height equals ellipsoid height from GNSS minus geoid separation N, with N obtained from a geoid model such as GEOID18.
- Combined factor
- Grid factor multiplied by elevation factor; grid distance divided by the combined factor gives ground distance, and ground distance times the factor gives grid distance.
- Relative precision
- Total traverse perimeter divided by the linear misclosure, stated as 1 to N; a larger N indicates a better closure relative to traverse length.
- PDOP
- Position dilution of precision reflects satellite geometry; lower values mean stronger geometry, and values of six or below are generally acceptable for RTK surveying.
- Temperature taping correction
- Ct equals 0.0000065 times the tape length times the temperature difference from standard in degrees Fahrenheit, using the thermal expansion coefficient of steel.
- Systematic versus random error
- Systematic errors are consistent biases that accumulate in one direction and can be modeled or corrected; random errors fluctuate and tend to cancel with repeated observations.
- Area by coordinates
- Twice the enclosed area equals the sum of each X multiplied by the difference of adjacent Y values, or the sum of each Y times adjacent X differences.
- Compass rule
- The Bowditch adjustment distributes latitude and departure misclosures in proportion to each course length divided by the total traverse perimeter.
- Transit rule
- An adjustment method that distributes misclosure in proportion to the magnitude of each course's latitude or departure rather than to course length.
- Tangent distance
- For a circular curve, T equals R times the tangent of half the central angle; the tangent runs from the PC or PT to the PI.
- Degree of curve, arc definition
- D equals 5729.578 divided by R in feet, defining the central angle subtended by a 100-foot arc; the chord definition uses twice the arcsine of 50 divided by R.
- Vertical curve K value
- K equals curve length divided by the algebraic difference in grades expressed in percent; K times the grade difference gives length for a given rate of change.
- Prismoidal volume
- Volume equals length divided by six times the sum of the two end areas plus four times the mid-section area; more accurate than average end area for varying sections.
- Least squares adjustment
- A method that minimizes the sum of squared residuals to find most probable coordinates, yielding standard deviations and error ellipses for the adjusted quantities.
- Order of boundary evidence
- Courts generally rank natural monuments first, then artificial monuments, then courses and distances, and last area when resolving conflicting deed calls.
- Meander line
- A line run to approximate a water boundary for computing area; it is not the boundary itself, which is the water body as it actually exists.
- Avulsion
- A sudden, perceptible change in a stream channel, such as a flood cutoff, that does not move the property boundary; the old boundary remains in place.
- Accretion
- The gradual and imperceptible addition of land by water action, where the riparian owner gains title to the added land without a new deed.
- Double proportionate measurement
- A BLM method of restoring a lost corner between two accepted corners by proportional distance along the line and, where needed, by latitude and departure.
- Adverse possession elements
- Possession must be actual, open and notorious, exclusive, hostile to the true owner, and continuous for the full statutory period to ripen into title.
- Large-scale map
- A map with a small representative fraction denominator, such as 1 to 1,200, showing more detail and covering less area than a small-scale map.
- Contour interval
- The constant vertical distance between adjacent contour lines; closer spacing indicates steeper slopes, and every fifth line is usually an indexed contour.
- Lambert conformal conic
- A conformal projection using a cone intersecting the globe along standard parallels, used for State Plane zones that extend mainly east to west.
- Base flood elevation
- The water surface elevation of the one percent annual chance flood shown on a FEMA Flood Insurance Rate Map, used to set floodplain building requirements.
- Variance
- Zoning relief granted when strict application of an ordinance causes unnecessary hardship unique to a parcel that the owner did not create.