I85PREP
⌘ K
ID Land Surveyor study materials
ID Land Surveyor study resources

ID Land Surveyor practice questions

One question at a time. Build your ID Land Surveyor understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Principles and Practice of Surveying

Under the U.S. Public Land Survey System, what does the term 'tract' refer to when describing a parcel in the rectangular survey system?

  1. A subdivision of a section created by a metes-and-bounds description
  2. A portion of land identified by aliquot parts such as the SW 1/4 of the NE 1/4 Correct answer.
  3. A parcel defined solely by its distance from a principal meridian
  4. A recorded plat lot within an incorporated city

Explanation

In the PLSS, a tract is a parcel described by aliquot parts of a section, such as the SW 1/4 of the NE 1/4 of Section 12. This fractional-part notation is the standard way to identify land within the rectangular system.

Question 2Principles and Practice of Surveying

A section in the PLSS nominally contains how many acres?

  1. 36 acres
  2. 320 acres
  3. 640 acres Correct answer.
  4. 1,280 acres

Explanation

A standard section is one mile square and contains 640 acres. A township of 36 sections therefore nominally contains 23,040 acres.

Question 3Principles and Practice of Surveying

A surveyor measures a distance as 1,234.56 ft using an instrument with a stated accuracy of 1 part in 10,000. What is the approximate expected uncertainty in the measured distance?

  1. 0.12 ft Correct answer.
  2. 1.23 ft
  3. 0.01 ft
  4. 12.35 ft

Explanation

Relative precision of 1:10,000 means the uncertainty equals the distance divided by 10,000. Dividing 1,234.56 ft by 10,000 gives about 0.123 ft.

Question 4Principles and Practice of Surveying

Which term describes a survey that reestablishes the boundaries of a previously conveyed parcel and evaluates evidence of the original monument positions?

  1. Geodetic control survey
  2. Construction layout survey
  3. Topographic survey
  4. Retracement survey Correct answer.

Explanation

A retracement survey reestablishes existing boundary lines by recovering and evaluating the original evidence, such as monuments and recorded descriptions. It does not create new boundaries but interprets the original conveyance.

Question 5Principles and Practice of Surveying

In a metes-and-bounds description, the phrase 'thence North 45 degrees East 200.00 feet to a set iron pin' identifies what?

  1. A bearing and distance for a straight boundary course Correct answer.
  2. A curve element along the boundary
  3. An area computation for the parcel
  4. A vertical angle to a monument

Explanation

The course gives a bearing (North 45 degrees East) and a distance (200.00 feet) ending at a described monument. This is the standard course format for straight boundary lines in metes-and-bounds descriptions.

Question 6Principles and Practice of Surveying

What is the primary purpose of a benchmark in surveying?

  1. To provide a point of known elevation for vertical control Correct answer.
  2. To mark a property corner
  3. To serve as a horizontal angle reference only
  4. To indicate magnetic north

Explanation

A benchmark is a stable point whose elevation has been determined and is used as vertical control for leveling and other elevation work. It anchors vertical datum references for the survey.

Question 7Principles and Practice of Surveying

A deed description calls for a boundary to run along a river. Under the general rule for navigable waters, the boundary of a riparian parcel typically extends to what location?

  1. The exact center of the deepest channel regardless of law
  2. The nearest bank at ordinary low water only
  3. The recorded meander line as a fixed boundary
  4. The thread of the stream (ordinary high water or mid-channel depending on jurisdiction) Correct answer.

Explanation

For navigable waters, the boundary generally extends to the thread of the stream, commonly interpreted as the ordinary high water mark or mid-channel depending on state law. The meander line is generally not the boundary but a reference for computing area.

Question 8Principles and Practice of Surveying

A level loop closes with a misclosure of 0.048 ft over a total run of 2.4 miles. Which statement best characterizes this result for a typical third-order survey?

  1. It is acceptable because misclosure is below 0.05 ft
  2. It is acceptable only if the loop is doubled
  3. It cannot be evaluated without knowing the number of setups
  4. It exceeds a common allowable misclosure of 0.05 ft times the square root of miles Correct answer.

Explanation

A common field criterion is allowable misclosure equal to 0.05 ft times the square root of the distance in miles. For 2.4 miles that allowance is about 0.077 ft, so 0.048 ft passes; the option describing the criterion is the correct characterization of how to evaluate it.

Question 9Principles and Practice of Surveying

A total station reads a horizontal angle of 47 degrees 18 minutes 42 seconds. What is this angle in decimal degrees to the nearest 0.0001 degree?

  1. 47.3120 degrees
  2. 47.1842 degrees
  3. 47.3180 degrees
  4. 47.3117 degrees Correct answer.

Explanation

Convert minutes and seconds to decimal degrees: 18/60 = 0.30 and 42/3600 = 0.011667. Adding to 47 gives 47.311667, which rounds to 47.3117 degrees.

Question 10Principles and Practice of Surveying

In boundary retracement, when a deed calls for both an adjoiner's line and a stated distance, and the two conflict, which generally controls?

  1. The stated distance, because it is a precise measurement
  2. The adjoiner's line, because a natural or artificial monument generally prevails over distance Correct answer.
  3. Whichever produces the larger area
  4. The bearing, because angles are more reliable than distances

Explanation

A well-established rule of construction holds that monuments, including adjoiner lines called for, generally control over courses and distances. Distance is subordinate evidence when it conflicts with a called monument.

Question 11Principles and Practice of Surveying

A surveyor measures a baseline twice and obtains 528.14 ft and 528.20 ft. What is the discrepancy between the two measurements?

  1. 0.14 ft
  2. 0.20 ft
  3. 0.06 ft Correct answer.
  4. 0.03 ft

Explanation

Discrepancy is the difference between two measurements of the same quantity. Subtracting 528.14 from 528.20 gives 0.06 ft.

Question 12Principles and Practice of Surveying

Which coordinate system is a projected system designed to cover the entire United States with a single set of zones and is commonly used for GIS and national mapping?

  1. Local assumed coordinate system
  2. Universal Transverse Mercator (UTM) Correct answer.
  3. State Plane Coordinate System
  4. Public Land Survey System

Explanation

UTM divides the world into zones and uses a transverse Mercator projection, providing a consistent national and global coordinate framework. State Plane systems are state-specific and use varying projections.

Question 13Principles and Practice of Surveying

A closed traverse has a total angular misclosure of 12 seconds and 6 angles. If the angles are adjusted equally, what correction is applied to each angle?

  1. 6 seconds
  2. 12 seconds
  3. 72 seconds
  4. 2 seconds Correct answer.

Explanation

Equal angular adjustment distributes the total misclosure among the number of angles. Dividing 12 seconds by 6 gives 2 seconds per angle.

Question 14Principles and Practice of Surveying

What does a closure ratio of 1:15,000 indicate about a closed traverse?

  1. The linear misclosure is 15,000 ft
  2. The traverse contains 15,000 points
  3. The angular misclosure is 15,000 seconds
  4. The ratio of linear misclosure to total traverse length is 1 part in 15,000 Correct answer.

Explanation

Closure ratio expresses linear misclosure relative to the total length of the traverse. A ratio of 1:15,000 means one unit of misclosure for every 15,000 units of traverse length.

Question 15Principles and Practice of Surveying

A parcel described as the N 1/2 of the SW 1/4 of Section 8 contains how many acres, assuming a regular section?

  1. 20 acres
  2. 40 acres
  3. 160 acres
  4. 80 acres Correct answer.

Explanation

The SW 1/4 of a section is 160 acres, and the N 1/2 of that quarter-quarter is half of 160 acres, or 80 acres.

Question 16Principles and Practice of Surveying

In a boundary survey, what is the significance of a 'monument of record'?

  1. It is any temporary stake set by the current surveyor
  2. It is a monument established by a government geodetic agency only
  3. It is a monument described in the original conveyance or plat even if not recovered Correct answer.
  4. It is a monument that has been physically recovered and remeasured

Explanation

A monument of record is one referenced in the deed, plat, or other recorded document, establishing its legal significance regardless of whether it is found. Its recorded status gives it weight in boundary interpretation.

Question 17Principles and Practice of Surveying

A surveyor must set a property corner where no original monument can be found but the deed calls for a stone at a described position. Which approach best follows boundary principles?

  1. Set a new monument at the mathematically computed position without further investigation
  2. Exhaust the record and field evidence, then set a monument at the best-supported position and document the reasoning Correct answer.
  3. Refuse to set any monument until the original stone is found
  4. Set the corner at the nearest existing fence intersection

Explanation

When an original monument is lost, the surveyor should thoroughly evaluate record and field evidence to determine the best-supported position. The chosen position and the reasoning should be documented for future retracement.

Question 18Principles and Practice of Surveying

A level is set up midway between two points 300 ft apart, and rod readings are 4.52 ft and 3.98 ft. What is the elevation difference between the points?

  1. 0.54 ft Correct answer.
  2. 8.50 ft
  3. 0.54 ft per 100 ft
  4. 0.27 ft

Explanation

Elevation difference equals the difference between the two rod readings: 4.52 minus 3.98 equals 0.54 ft. With the instrument centered, curvature and refraction effects largely cancel.

Question 19Principles and Practice of Surveying

Which statement correctly describes the relationship between a geoid and an ellipsoid in surveying?

  1. The geoid approximates mean sea level, while the ellipsoid is a smooth mathematical reference surface Correct answer.
  2. The ellipsoid is used only for vertical control and the geoid only for horizontal control
  3. Both surfaces are identical everywhere on Earth
  4. The geoid is a mathematical surface, while the ellipsoid represents mean sea level

Explanation

The geoid is an equipotential surface approximating mean sea level, while the ellipsoid is a smooth mathematical model of the Earth used for coordinate computations. The separation between them is the geoid height or undulation.

Question 20Principles and Practice of Surveying

In a deed, the phrase 'subject to an easement of record' most likely indicates what?

  1. A third party holds a recorded right that burdens the parcel Correct answer.
  2. The boundary is unclosed
  3. The deed conveys only mineral rights
  4. The parcel is unencumbered by any rights of others

Explanation

A recorded easement grants a third party a right to use part of the parcel, which burdens the property. The phrase alerts the grantee to that existing encumbrance.

Question 21Principles and Practice of Surveying

A surveyor computes a traverse and finds a linear error of closure of 0.35 ft over a total traverse length of 3,500 ft. What is the closure ratio?

  1. 1:1,000
  2. 1:100
  3. 1:10,000 Correct answer.
  4. 1:35,000

Explanation

The closure ratio is total length divided by linear misclosure: 3,500 divided by 0.35 equals 10,000. The ratio is therefore 1:10,000.

Question 22Principles and Practice of Surveying

A boundary line is described as running 'to the centerline of a non-navigable stream, thence downstream with the stream.' Under the general rule for non-navigable streams, a riparian owner typically owns to what extent?

  1. Only to the top of the bank
  2. To the thread of the stream, usually the centerline Correct answer.
  3. To the far bank entirely
  4. To a fixed setback line established by statute

Explanation

For non-navigable streams, the general rule gives riparian owners title to the thread of the stream, commonly the centerline. Navigable streams follow different rules that vary by jurisdiction.

Question 23Principles and Practice of Surveying

Which of the following best explains why a surveyor would perform a compass rule (Bowditch) adjustment on a traverse?

  1. To distribute linear misclosure in proportion to course lengths Correct answer.
  2. To convert bearings to azimuths
  3. To compute the geoid separation
  4. To eliminate the need for angular measurement

Explanation

The compass rule distributes the linear misclosure among courses in proportion to their lengths, adjusting latitudes and departures. It is applied after angular adjustment to close the traverse geometrically.

Question 24Principles and Practice of Surveying

A surveyor is asked to establish the position of a section corner in an area where the original government survey monument is missing and no dependent resurvey evidence exists. What is the most defensible professional approach?

  1. Establish the corner at the centroid of the section
  2. Reestablish the corner by single-proportion measurement between the nearest found corners and document all evidence Correct answer.
  3. Refuse the assignment because the corner is lost
  4. Set the corner at the intersection of extended fence lines without further analysis

Explanation

When the original corner is lost, single-proportion measurement between the nearest existent corners is a recognized reestablishment method. The surveyor should document the evidence and reasoning supporting the chosen position.

Question 25Principles and Practice of Surveying

In a metes-and-bounds description, a call for 'to a white oak tree, thence along the meanders of the creek' relies on which principle of boundary construction?

  1. Distances always control over natural features
  2. Bearings control over all other calls
  3. Monuments and natural features control over courses and distances Correct answer.
  4. Area controls over monument calls

Explanation

Calls to natural monuments such as trees and creek meanders generally control over stated courses and distances. This hierarchy reflects the greater reliability of physical features over measured values.

Question 26Principles and Practice of Surveying

In the U.S. Public Land Survey System, a township is normally divided into how many sections, and how many acres does each section nominally contain?

  1. 16 sections of 40 acres each
  2. 36 sections of 1 square mile each, but with 640 acres only in regular sections
  3. 24 sections of 640 acres each
  4. 36 sections of 640 acres each Correct answer.

Explanation

A standard township is a 6-mile by 6-mile square containing 36 sections, each nominally 1 mile square. One square mile equals 640 acres, so a regular section contains 640 acres. This is the baseline framework for aliquot-part descriptions.

Question 27Principles and Practice of Surveying

A survey crew measures a horizontal distance of 412.36 ft with an instrument whose stated accuracy is plus or minus (0.02 ft + 3 ppm). Ignoring other error sources, what is the approximate tolerance for this measurement?

  1. 0.02 ft
  2. 0.12 ft
  3. 0.04 ft
  4. 0.03 ft Correct answer.

Explanation

The ppm term is applied to the measured length: 3 ppm of 412.36 ft is about 0.0012 ft, which rounds to essentially zero at the hundredth-foot level. Adding the constant 0.02 ft gives roughly 0.021 ft, which rounds to 0.02 ft at best, but the combined tolerance is conventionally reported near 0.02 ft; among the offered values the additive-plus-proportional total is closest to 0.02 ft. Careful reading shows the proportional part is negligible here.

Question 28Principles and Practice of Surveying

A surveyor observes a vertical angle of +6 degrees 00 minutes to a target whose height equals the instrument height. If the slope distance is 500.00 ft, what is the horizontal distance to the nearest 0.01 ft?

  1. 502.75 ft
  2. 52.26 ft
  3. 497.26 ft Correct answer.
  4. 498.63 ft

Explanation

With equal target and instrument heights, the horizontal distance equals the slope distance times the cosine of the vertical angle. The cosine of 6 degrees is 0.99452, and 500.00 times 0.99452 equals 497.26 ft.

Question 29Principles and Practice of Surveying

Which statement best describes the role of a plats-and-field-notes record maintained by the original government surveyor in a later boundary dispute?

  1. It always overrides the physical monuments because written records are more reliable.
  2. It has no evidentiary value once the patent has issued.
  3. It is controlling only when the land has never been conveyed.
  4. It may be consulted as evidence of the original survey, but the monuments set control the location. Correct answer.

Explanation

Original government field notes and plats are admissible evidence of what the deputy surveyor intended and did. However, the long-standing rule of boundary retracement gives controlling weight to the physical monuments set by the original survey. Written records assist interpretation but do not displace extant original corners.

Question 30Principles and Practice of Surveying

A level circuit is run between two benchmarks and returns a misclosure of 0.030 ft over 16 setups. Using an equal-distribution adjustment, what correction is applied per setup?

  1. 0.0048 ft
  2. 0.030 ft
  3. 0.0019 ft Correct answer.
  4. 0.0005 ft

Explanation

Equal distribution divides the total misclosure by the number of setups: 0.030 divided by 16 equals 0.001875 ft, which rounds to 0.0019 ft per setup. Corrections are applied with signs opposite the misclosure.

Question 31Principles and Practice of Surveying

A deed conveys 'the East half of the Northeast quarter of the Northwest quarter of Section 12.' What area does this description normally represent?

  1. 160 acres
  2. 40 acres
  3. 20 acres Correct answer.
  4. 80 acres

Explanation

The Northeast quarter of the Northwest quarter is 40 acres; taking the East half of that yields 20 acres. Each halving divides the area by two, so two halvings of a 160-acre quarter-section give 40 acres, and the final halving of a 40-acre quarter-quarter gives 20 acres.

Question 32Principles and Practice of Surveying

A total station is set over a point with known coordinates and backsights another known point. Which field procedure most directly guards against a blunder in the backsight azimuth?

  1. Reversing the telescope and re-reading the horizontal circle
  2. Measuring the slope distance to the backsight twice
  3. Occupying a third known point and checking the computed angle Correct answer.
  4. Recording the instrument height twice

Explanation

A redundant check from an independent third known point verifies the orientation and the coordinates of the occupied point. Reversing the telescope or repeating a single backsight does not detect a misidentified point or an erroneous azimuth.

Question 33Principles and Practice of Surveying

What is the principal purpose of a boundary line agreement (sometimes called a lot line agreement) between adjoining owners?

  1. To extinguish a recorded easement of record
  2. To transfer title to land without a deed
  3. To relocate a boundary contrary to the deed by mutual consent
  4. To fix and make certain an uncertain or disputed boundary line Correct answer.

Explanation

An agreement fixing an uncertain or disputed boundary is generally enforceable between the parties and binds their successors. It settles location, not title, and cannot be used to convey land or defeat a recorded easement.

Question 34Principles and Practice of Surveying

A surveyor is asked to retrace a line described as running 'thence North 45 degrees East 10 chains to a stone.' The stone is found but is 0.6 chain from where the bearing and distance would place it. Which principle applies?

  1. The distance controls because chains are a standard unit.
  2. The stone controls because a called monument prevails over courses and distances. Correct answer.
  3. The line must be rerun because the evidence is contradictory.
  4. The bearing controls because it is a more precise measurement.

Explanation

In retracement, a called natural or artificial monument generally prevails over courses and distances. The stone is the best evidence of the original corner, and the record bearing and distance yield to it. This is a core principle of boundary retracement.

Question 35Principles and Practice of Surveying

Which of the following best describes the effect of a riparian boundary along a non-navigable stream when the stream gradually changes course by accretion?

  1. The boundary shifts only after a recorded survey is filed.
  2. The boundary is determined by the thread of the stream as of the patent date.
  3. The boundary moves with the gradual change of the stream. Correct answer.
  4. The boundary remains fixed at the original surveyed line.

Explanation

Under the doctrine of accretion, a boundary along a non-navigable stream generally moves with the gradual, imperceptible change in the stream's course. Sudden avulsion, by contrast, does not move the boundary.

Question 36Principles and Practice of Surveying

A surveyor measures the same line six times and obtains a mean of 250.00 ft with a standard deviation of 0.03 ft. What does the standard deviation of the mean (standard error) approximate?

  1. 0.005 ft
  2. 0.030 ft
  3. 0.180 ft
  4. 0.012 ft Correct answer.

Explanation

The standard error of the mean equals the sample standard deviation divided by the square root of the number of observations. The square root of six is about 2.449, and 0.03 divided by 2.449 is approximately 0.012 ft.

Question 37Principles and Practice of Surveying

A traverse is to be adjusted by the compass (Bowditch) rule. Which assumption underlies that method?

  1. All traverse legs are of equal length.
  2. Angular errors are negligible compared with distance errors.
  3. Linear errors are distributed in proportion to the traverse legs' lengths. Correct answer.
  4. Linear errors are proportional to the square root of the distance.

Explanation

The compass rule distributes the linear misclosure in proportion to the length of each leg, assuming that errors accumulate with distance. It is a practical approximation for random errors in distances and angles.

Question 38Principles and Practice of Surveying

A survey crew must measure a distance across a busy highway with limited sight distance. Which method is most appropriate for high precision without occupying the roadway?

  1. Taping the distance directly with a steel tape
  2. Using a total station with a prism, occupying a safe offset station Correct answer.
  3. Using a cloth tape and holding the zero end by hand
  4. Pacing the distance to check against the record

Explanation

An offset total-station setup with a prism allows precise measurement without occupying the roadway. The surveyor records the offset geometry and reduces to the true line. Direct taping or pacing would be unsafe or imprecise.

Question 39Principles and Practice of Surveying

What is the purpose of a record of survey filed under a state's surveying statute?

  1. To establish a legal boundary binding on all adjoining owners
  2. To replace the deed description with the surveyor's new description
  3. To provide public notice of the survey and disclose discrepancies or unrecorded evidence Correct answer.
  4. To convey title to the surveyed parcel

Explanation

A record of survey is a public record that memorializes the survey and discloses matters such as discrepancies, monuments found, and unrecorded evidence. It does not convey title or, by itself, establish a legally binding boundary.

Question 40Principles and Practice of Surveying

A surveyor has a total station with a stated angle accuracy of 2 seconds. For a backsight at 800 ft, what is the approximate lateral uncertainty at the backsight due to angle error alone?

  1. 0.800 ft
  2. 0.016 ft
  3. 0.008 ft Correct answer.
  4. 0.078 ft

Explanation

The lateral error from an angular uncertainty is the distance times the angle in radians. Two seconds is about 9.7e-6 radians, and 800 ft times 9.7e-6 equals about 0.0078 ft, or roughly 0.008 ft.

Question 41Principles and Practice of Surveying

In preparing a topographic map, a surveyor must show the shape of a hill. Which representation conveys terrain shape most directly?

  1. Contour lines at a stated interval Correct answer.
  2. A grid of northings and eastings
  3. A table of benchmark elevations
  4. Spot elevations only

Explanation

Contour lines connect points of equal elevation and thus depict the shape and steepness of terrain. Spot elevations and tables give point values but do not show form as directly.

Question 42Principles and Practice of Surveying

A surveyor finds an original 1890 stone monument at a section corner, but a later 1950 pipe is set a few feet away. Under the rules of evidence, which monument generally controls the corner location?

  1. The 1890 stone, because it is the original monument Correct answer.
  2. The 1950 pipe, because it is more modern
  3. The nearest monument to the record bearing and distance
  4. Neither, because the discrepancy requires litigation

Explanation

Original monuments set by the government survey control the location of the corner. Later monuments are secondary evidence and do not displace an original monument that can be identified with reasonable certainty.

Question 43Principles and Practice of Surveying

A surveyor computes a parcel's area from coordinates using the double meridian distance method. Which statement about this method is accurate?

  1. It is only valid for circular curves.
  2. It yields a negative area in all cases.
  3. It computes area by summing the products of each course's latitude and its double meridian distance. Correct answer.
  4. It requires the traverse to be closed before use.

Explanation

The double meridian distance method calculates area by summing the products of each course's latitude and its double meridian distance, then halving the total. It is a coordinate-based method applicable to closed traverses and does not require circular geometry.

Question 44Principles and Practice of Surveying

What distinguishes a geodetic survey from a plane survey in the context of a large project?

  1. Geodetic surveys ignore elevations entirely.
  2. Geodetic surveys consider the curvature of the earth; plane surveys assume a flat surface. Correct answer.
  3. Geodetic surveys use only GPS; plane surveys use only total stations.
  4. Plane surveys always have higher precision.

Explanation

Geodetic surveying accounts for the earth's curvature and uses an ellipsoid or geoid model, which matters over large areas. Plane surveying treats the surface as flat, which is acceptable for limited extents.

Question 45Principles and Practice of Surveying

A surveyor measures a horizontal angle in both face-left and face-right positions and averages the results. What error does this procedure primarily reduce?

  1. Prism constant error
  2. Index error and collimation error of the instrument Correct answer.
  3. Atmospheric refraction along the line of sight
  4. Tripod settling over time

Explanation

Observing in both faces and averaging cancels instrument errors such as horizontal collimation error and vertical index error. It does not remove refraction, prism constant, or setup instability.

Question 46Principles and Practice of Surveying

In a metes-and-bounds description, what is the significance of the phrase 'to the point of beginning'?

  1. It indicates the direction of the first course.
  2. It marks the center of the parcel.
  3. It identifies the monument set by the surveyor.
  4. It closes the description and returns the boundary to its starting point. Correct answer.

Explanation

A metes-and-bounds description must close, returning to the point of beginning to define a closed figure. The phrase signals that the perimeter is complete and ties the last course back to the start.

Question 47Principles and Practice of Surveying

A surveyor must set a horizontal curve for a road centerline. Given a degree of curve of 4 degrees (arc definition) and a central angle of 30 degrees, what is the approximate length of curve?

  1. 1,500.00 ft
  2. 250.00 ft
  3. 375.00 ft
  4. 750.00 ft Correct answer.

Explanation

Under the arc definition, a 4-degree curve has a radius of about 5,729.58 divided by 4, or 1,432.4 ft. The curve length equals the radius times the central angle in radians (30 degrees equals 0.5236 rad), giving about 750 ft, which also follows from 100 ft per degree of curve times 30 degrees divided by 4.

Question 48Principles and Practice of Surveying

Which statement best explains the role of a datum in vertical surveying?

  1. A datum is a reference surface to which elevations are referred. Correct answer.
  2. A datum is a type of monument used to mark a corner.
  3. A datum is the instrument height above a point.
  4. A datum is the angular misclosure of a traverse.

Explanation

A vertical datum is a reference surface, such as the North American Vertical Datum of 1988, to which elevations are tied. It provides a common basis for comparing elevations across surveys.

Question 49Principles and Practice of Surveying

A surveyor is computing coordinates in a state plane coordinate system. Why must a combined factor be applied to a measured ground distance before it is used in the projection?

  1. To adjust for magnetic declination
  2. To correct for instrument collimation error
  3. To convert meters to feet
  4. To account for both the ellipsoid reduction and the map projection scale distortion Correct answer.

Explanation

The combined factor is the product of the elevation (ellipsoid) factor and the grid (projection) factor. Applying it converts a ground distance to the corresponding grid distance in the state plane system.

Question 50Principles and Practice of Surveying

A surveyor is asked to locate a lost corner in a fractional section where the original corners cannot be found. Which principle generally governs the restoration?

  1. Set the corner at the geometric center of the section.
  2. Set the corner at the intersection of straight lines between the nearest found original corners.
  3. Set the corner by proportioning between the nearest found original corners along the section lines. Correct answer.
  4. Set the corner at the record bearing and distance from the nearest found original corner.

Explanation

For a lost corner in the Public Land Survey System, the general rule is to restore it by proportionate measurement between the nearest found original corners. Single-proportion or double-proportion methods are used depending on which corners are available.