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Oklahoma Land Surveyor (OLS) Exam study materials
Oklahoma Land Surveyor (OLS) Exam study resources

Oklahoma Land Surveyor (OLS) Exam practice questions

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Question 1Boundary Surveying and Land Descriptions

Under the U.S. Public Land Survey System, a standard section of land contains how many acres?

  1. 1,280 acres
  2. 160 acres
  3. 320 acres
  4. 640 acres Correct answer.

Explanation

A regular section in the PLSS is one mile square, measuring 5,280 feet on each side, which yields 640 acres. Quarter-sections of 160 acres and half-sections of 320 acres are subdivisions of that standard section rather than the section itself.

Question 2Boundary Surveying and Land Descriptions

In the PLSS, township and range numbering is referenced to which pair of lines?

  1. A meander line and a section line
  2. A lot line and a block line
  3. A principal meridian and a base line Correct answer.
  4. A record line and an occupation line

Explanation

Townships are counted north or south from a base line, and ranges are counted east or west from a principal meridian. Together these two reference lines establish the initial point from which the rectangular system is extended.

Question 3Boundary Surveying and Land Descriptions

A metes-and-bounds description that begins at a monument and returns to that same monument is said to be:

  1. Closed Correct answer.
  2. Open
  3. Ambiguous
  4. Unbalanced

Explanation

A closed description returns to its point of beginning, allowing the parcel to be mathematically and physically enclosed. An open description stops short of returning to the POB and cannot be definitively located without outside evidence.

Question 4Boundary Surveying and Land Descriptions

Which term describes a right of one parcel to pass over the land of another?

  1. Encroachment
  2. Easement Correct answer.
  3. Adverse possession
  4. Fee simple

Explanation

An easement is a nonpossessory interest granting a right of use over another's land, such as a right of passage. It does not convey ownership of the burdened parcel, only a limited right of use.

Question 5Boundary Surveying and Land Descriptions

A monument called for in a deed is found to be in place and undisturbed. Under the hierarchy of evidence, that monument generally controls over:

  1. The tax assessor's parcel map
  2. The surveyor's opinion of intent
  3. The recorded distance in the deed Correct answer.
  4. The adjoining owner's recollection

Explanation

Natural and artificial monuments called for in a conveyance generally control over courses and distances because monuments are considered the best evidence of the parties' intent. Distances yield when they conflict with an undisturbed monument.

Question 6Boundary Surveying and Land Descriptions

The phrase "subject to" in a deed most commonly indicates that the grantee's title is:

  1. Held only for a term of years
  2. Burdened by an existing right or interest Correct answer.
  3. Conditional on future payment of taxes
  4. Free of all encumbrances

Explanation

Language such as "subject to" acknowledges an existing encumbrance or interest that continues to burden the property. It does not create a new interest; it recognizes one already in place.

Question 7Boundary Surveying and Land Descriptions

In a metes-and-bounds description, the term "thence" is used to:

  1. Introduce the next course and distance Correct answer.
  2. Describe an adjoining parcel
  3. Declare an exception to the grant
  4. Designate the point of beginning

Explanation

"Thence" is a transitional word that introduces each successive course and distance after the initial call from the point of beginning. It signals progression along the boundary rather than the start or an exclusion.

Question 8Boundary Surveying and Land Descriptions

A parcel described as the "SW 1/4 of the NE 1/4" of a section contains approximately how many acres?

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

Explanation

Each quartering step halves the linear dimension, dividing the area by four. A quarter-section is 160 acres, and a quarter of that quarter is 40 acres, so the SW 1/4 of the NE 1/4 contains about 40 acres.

Question 9Boundary Surveying and Land Descriptions

A surveyor finds that the record distance between two found original corners differs from the measured distance by several feet. The most defensible approach in a boundary retracement is to:

  1. Disregard the original corners as unreliable
  2. Move the corners to match the record distance exactly
  3. Average the record and measured distances at each corner
  4. Hold the found corners and proportion the discrepancy as evidence dictates Correct answer.

Explanation

Original corners, once accepted as the true corners, control the record distances, and discrepancies are resolved by evidence rather than by relocating monuments. The retracement surveyor's role is to locate the original boundary, not to create a new one.

Question 10Boundary Surveying and Land Descriptions

In the PLSS, which section within a normal township lies directly north of Section 6?

  1. Section 7
  2. Section 36
  3. Section 1
  4. Section 31 Correct answer.

Explanation

Sections are numbered boustrophedon from the southeast corner, so Section 6 sits in the northeast corner of a township. The section immediately north of Section 6 belongs to the adjacent township and is numbered Section 31 for that township.

Question 11Boundary Surveying and Land Descriptions

A senior right held by long-standing use over a junior parcel is best described as a right acquired by:

  1. Prescription Correct answer.
  2. Dedication
  3. Escheat
  4. Condemnation

Explanation

Prescriptive easements arise from open, notorious, hostile, and continuous use for the statutory period, creating a right against another's land. Dedication and condemnation involve public or governmental action, and escheat concerns reversion to the state.

Question 12Boundary Surveying and Land Descriptions

A deed conveys "the north half of the northwest quarter." How many acres does this description represent, assuming a regular section?

  1. 160 acres
  2. 80 acres Correct answer.
  3. 320 acres
  4. 40 acres

Explanation

The northwest quarter of a regular section is 160 acres, and its north half is half of that area, or 80 acres. The order of the aliquot calls is read from right to left, so the quarter is taken first, then halved.

Question 13Boundary Surveying and Land Descriptions

Which of the following best describes a "meander line" in the PLSS?

  1. A line marking the center of a public road
  2. The true boundary line of a riparian parcel
  3. A line run to determine the approximate area of a fractional lot along a water body Correct answer.
  4. A line established to divide two adjoining private parcels

Explanation

Meander lines are run along the banks of navigable waters to compute the area of fractional lots and are not themselves the boundary. The water's edge or the ordinary high water mark is generally the boundary, subject to state law.

Question 14Boundary Surveying and Land Descriptions

A description calls for a boundary to run "to a stone at the northeast corner of the Jones tract, thence along Jones' line to a post." This is an example of a call for:

  1. A course and distance
  2. An exception
  3. A natural monument
  4. An adjoiner Correct answer.

Explanation

A call to an adjoining owner's line or corner is an adjoiner call, which helps locate the boundary through reference to a neighboring parcel. Adjoiner calls are often given weight comparable to or greater than courses and distances.

Question 15Boundary Surveying and Land Descriptions

A surveyor discovers that a fence has been treated as the boundary for many years, though the deed line lies several feet away. Under the doctrine of practical location, the fence line may:

  1. Control only if the fence is a natural monument
  2. Control the boundary if the parties acquiesced in it for the statutory period Correct answer.
  3. Control only if both owners are absent from the property
  4. Have no effect because the deed line always controls

Explanation

Practical location and acquiescence doctrines allow a long-established and mutually accepted boundary line to control over the record line. The key elements are mutual recognition of the line and passage of the statutory period.

Question 16Boundary Surveying and Land Descriptions

A deed description gives a bearing, distance, and monument, and the monument and distance conflict. Which principle guides the surveyor?

  1. Distances control over monuments
  2. Monuments control over distances Correct answer.
  3. The deed is void and must be rewritten
  4. Bearings control over monuments

Explanation

In the hierarchy of calls, natural and artificial monuments ordinarily prevail over courses and distances. The surveyor should locate the monument and adjust the distance rather than relocate the monument.

Question 17Boundary Surveying and Land Descriptions

In Oklahoma, which statute governs the recording of deeds and other instruments affecting real property?

  1. The Oklahoma Recording Statute Correct answer.
  2. The Oklahoma Adverse Possession Act
  3. The Oklahoma Subdivision Control Act
  4. The Oklahoma Easement Act

Explanation

Oklahoma's recording statutes establish the requirements and effect of recording instruments affecting real property. Recording gives constructive notice and determines priority among competing interests under the state's race-notice framework.

Question 18Boundary Surveying and Land Descriptions

A surveyor prepares a plat showing a new subdivision. Which element is essential to make the plat legally effective as a conveyance of the lots?

  1. Obtaining a surveyor's seal only
  2. Recording the plat after required approvals Correct answer.
  3. Publishing the plat in a newspaper
  4. Posting the plat at the county courthouse

Explanation

A subdivision plat must be approved as required by statute and local ordinance and then recorded to give legal effect and convey lots by reference. A seal alone or publication does not substitute for recording.

Question 19Boundary Surveying and Land Descriptions

A boundary line is described as running "N 45° E a distance of 100.00 feet." What does the bearing indicate?

  1. The line runs southeast at 45 degrees from south
  2. The line runs northwest at 45 degrees from west
  3. The line runs northeast at 45 degrees from north Correct answer.
  4. The line runs due east for 45 feet

Explanation

A bearing of N 45° E means the line is measured 45 degrees east of due north, so it runs northeast. The distance of 100.00 feet is the length along that bearing.

Question 20Boundary Surveying and Land Descriptions

Which of the following is the best example of a natural monument in a boundary description?

  1. A stone marker
  2. A river Correct answer.
  3. A concrete monument
  4. An iron pin

Explanation

Natural monuments are features of the landscape such as rivers, streams, trees, and ridges. Artificial monuments include set pins, concrete monuments, and stones placed by surveyors.

Question 21Boundary Surveying and Land Descriptions

A deed describes a parcel as "beginning at the NW corner of Section 14, thence east 660 feet, thence south 660 feet, thence west 660 feet, thence north 660 feet to the point of beginning." What is the approximate area?

  1. 5 acres
  2. 20 acres
  3. 40 acres
  4. 10 acres Correct answer.

Explanation

The parcel is 660 feet by 660 feet, which is 435,600 square feet, and one acre equals 43,560 square feet. Dividing yields approximately 10 acres.

Question 22Boundary Surveying and Land Descriptions

A surveyor must resolve a conflict between a called-for distance and a called-for bearing when no monument is available. Under traditional rules of construction, which generally prevails?

  1. Neither; the deed is void
  2. The bearing Correct answer.
  3. The distance
  4. The longer of the two

Explanation

When no monument is available, courses and bearings generally prevail over distances because angular calls are less susceptible to error than measured lengths. Distances are adjusted to close the figure consistent with the bearings.

Question 23Boundary Surveying and Land Descriptions

A parcel abuts a non-navigable stream. Under the common-law rule generally applied, the boundary of the parcel extends to:

  1. The center of the stream, subject to the state's rights Correct answer.
  2. The nearest public road
  3. The meander line only
  4. The ordinary high water mark on the far bank

Explanation

For non-navigable streams, the common-law rule extends riparian boundaries to the thread or center of the stream, subject to the state's sovereign interests. Navigable waters are treated differently, with boundaries typically at the ordinary high water mark.

Question 24Boundary Surveying and Land Descriptions

A surveyor retraces a PLSS township and finds that the north and west tiers of sections are fractional. What is the principal reason for this?

  1. Convergence of meridians and accumulated measurement error in the original survey Correct answer.
  2. Deliberate omission of sections by the original surveyor
  3. The presence of navigable waters throughout the township
  4. Errors in the recording of the township plat

Explanation

Because meridians converge toward the poles and original surveys accumulated error, the north and west tiers are adjusted as fractional lots to absorb the excess or deficiency. Standard parallels and correction lines are used to control this convergence.

Question 25Boundary Surveying and Land Descriptions

A deed contains a call to a monument that no longer exists, but the surveyor finds evidence of the original position through collateral evidence. The best practice is to:

  1. Set a new corner at the record distance from the nearest found corner
  2. Reestablish the corner at its original position using the collateral evidence Correct answer.
  3. Set the corner at the midpoint between the nearest found corners
  4. Disregard the missing monument and hold the record bearing

Explanation

When an original monument is lost, the surveyor should reestablish it at its original position using the best available collateral evidence, such as bearing trees, fences, or field notes. Creating a new position by distance alone would not restore the original boundary.

Question 26Boundary Surveying and Land Descriptions

A deed describes a parcel as the "E 1/2 of the SE 1/4 of the SW 1/4" of a section. Assuming a regular section of 640 acres, how many acres does the parcel contain?

  1. 80 acres
  2. 40 acres
  3. 20 acres Correct answer.
  4. 10 acres

Explanation

Halving the quarter-quarter-quarter aliquot parts: the SW 1/4 contains 160 acres, its SE 1/4 contains 40 acres, and the east half of that contains 20 acres. Each successive aliquot division halves the area, so three halvings of 160 acres yield 20 acres.

Question 27Boundary Surveying and Land Descriptions

In a metes-and-bounds description, a call reading "thence N 30° E 200.0 feet to an iron pin" is best characterized as which element of the description?

  1. A general recital
  2. A call for adjoiner
  3. A course and distance call Correct answer.
  4. A call for quantity

Explanation

A bearing together with a distance constitutes a course and distance call, which is one of the calls that may control or be controlled by other calls. The iron pin is a separate monument call, and a call for quantity would state an acreage.

Question 28Boundary Surveying and Land Descriptions

A deed conveys a parcel "beginning at a point on the north right-of-way line of County Road 12, 50 feet north of the centerline thereof." The road is a dedicated public highway. What does this description establish about the parcel's south line?

  1. The south line is the north right-of-way line, 50 feet from the centerline. Correct answer.
  2. The south line is the centerline of the road, subject to the public easement.
  3. The south line is the centerline of the road free of any easement.
  4. The south line is undefined because the road width is not stated.

Explanation

When a deed fixes the boundary at a stated offset from a road centerline, that offset line is the boundary; the fee does not extend to the centerline. The 50-foot call locates the right-of-way line expressly, so it controls over any presumption about centerline ownership.

Question 29Boundary Surveying and Land Descriptions

A section is subdivided and the surveyor must locate the "N 1/2 of the SW 1/4" of a section that has been shown by government survey to contain 645 acres. How is the aliquot part area computed?

  1. One-half of the record area of the SW 1/4 as returned by the government survey Correct answer.
  2. By measuring the parcel and using the measured area only
  3. One-half of 640 acres regardless of the government return
  4. Pro rata by the ratio of the section's excess to 640 acres applied to 80 acres

Explanation

Aliquot parts are apportioned from the government-survey area of the parent tract, so a half of a quarter takes half of that quarter's returned area. The excess or deficiency in the section is absorbed in the aliquot division rather than ignored.

Question 30Boundary Surveying and Land Descriptions

A deed calls for a boundary to run "to the center of Dry Creek, thence down the creek with its meanders." Dry Creek is non-navigable. What does the grantee receive under the common-law rule?

  1. Title only to the bank, with the bed remaining in the grantor
  2. Title to the bed to the thread of the stream, subject to the public right of passage Correct answer.
  3. Title to the entire bed of the stream to the far bank
  4. No riparian rights, because the creek is not navigable

Explanation

For non-navigable streams, the common-law rule carries a boundary to the thread (center) of the stream, subject to the public right of passage. The call to the center and down the meanders confirms this construction.

Question 31Boundary Surveying and Land Descriptions

A surveyor retracing a township finds that the lots along the north boundary of the township are numbered from west to east as Lots 1, 2, 3, and so on. Which principle explains this numbering?

  1. Fractional lots are numbered by their aliquot part designations rather than by lot number.
  2. Fractional lots are numbered from east to west in both the north and west tiers.
  3. Fractional lots in the north tier are numbered from west to east, while those in the west tier are numbered from north to south. Correct answer.
  4. All fractional lots in a township are numbered consecutively starting at the southeast corner.

Explanation

In the PLSS, subdivision-of-section lots in the north tier are numbered from west to east, and lots in the west tier are numbered from north to south. This convention reflects the order in which the closing lines are run.

Question 32Boundary Surveying and Land Descriptions

A deed describes a tract by reference to a recorded plat, and the plat shows a monument at a corner that is not mentioned in the deed text. What is the effect of the plat reference?

  1. The plat controls only if the surveyor who prepared it is still living.
  2. The plat reference is merely informational and has no legal effect on the boundaries.
  3. The plat controls only if the deed also states the acreage shown on the plat.
  4. The plat is incorporated into the deed, and its monuments and lines are part of the description. Correct answer.

Explanation

A deed that refers to a recorded plat incorporates that plat by reference, making its lines, monuments, and lot designations part of the conveyance. Extrinsic information in the plat then has the same force as if written into the deed.

Question 33Boundary Surveying and Land Descriptions

A description reads: "Beginning at the NE corner of Section 22, thence west 1,320 feet, thence south 1,320 feet, thence east 1,320 feet, thence north to the point of beginning." Assuming a regular section, what does this describe?

  1. The SE 1/4 of Section 22
  2. The NW 1/4 of Section 22 Correct answer.
  3. The NE 1/4 of Section 22
  4. The SW 1/4 of Section 22

Explanation

Starting at the NE corner and going west 1,320 feet reaches the NW corner; going south 1,320 feet reaches the west quarter corner area, enclosing the northwest quarter. The closing line returns north along the section line to the point of beginning.

Question 34Boundary Surveying and Land Descriptions

In a metes-and-bounds description, the phrase "to a point on the easterly line of the Smith tract, thence northerly along said line" contains which type of call that may control over a conflicting bearing?

  1. A call for a general warranty
  2. A call for quantity
  3. A call for a natural monument
  4. A call for an adjoiner's line Correct answer.

Explanation

A call for the line of an adjoining tract is an adjoiner call, which is a monument call and generally controls over courses and distances. The reference to the Smith line fixes the boundary even if the recited bearing is slightly off.

Question 35Boundary Surveying and Land Descriptions

A deed conveys "all that part of the SE 1/4 of Section 8 lying north of State Highway 9 as said highway is now located." The highway has since been relocated. What boundary governs the conveyed parcel?

  1. The location of the highway as relocated, because the highway is a monument
  2. The north line of the SE 1/4, because the highway reference fails
  3. The centerline of the original highway right-of-way only
  4. The location of the highway as it existed at the date of the deed Correct answer.

Explanation

A call to a monument "as now located" fixes the boundary at the monument's position when the deed was made. Later movement of the monument does not move the deed line, which remains where the highway lay at conveyance.

Question 36Boundary Surveying and Land Descriptions

A surveyor finds a bearing tree marked with the original surveyor's blaze and scribed marks at a position consistent with the field notes, though the corner monument itself is gone. What is the proper treatment of the bearing tree?

  1. It is irrelevant because only the corner monument itself can establish the corner.
  2. It may be used only if the original field notes are unavailable.
  3. It establishes a new corner at the tree's own location, replacing the original corner.
  4. It is acceptable evidence of the original corner position and may be used to reestablish the corner. Correct answer.

Explanation

Bearing trees are recognized PLSS evidence of the original corner location and are used to reestablish a lost corner. Their scribed marks and consistency with the field notes give them weight as original evidence.

Question 37Boundary Surveying and Land Descriptions

A deed conveys "the north half of the northwest quarter" of a section, and a later deed from the same grantor conveys "the northwest quarter of the northwest quarter." What is the relationship of the two parcels?

  1. The second parcel lies entirely within the first, creating an overlap as to that quarter-quarter. Correct answer.
  2. The second parcel is junior and therefore voids the first conveyance as to the overlap.
  3. The second parcel takes the south half of the first parcel by operation of law.
  4. The two parcels are entirely separate and do not overlap.

Explanation

The north half of the northwest quarter includes the northwest quarter of the northwest quarter, so the later deed overlaps the earlier one as to that 40-acre tract. The overlap is resolved by priority rules, not by redrawing the parcels.

Question 38Boundary Surveying and Land Descriptions

A metes-and-bounds description closes with a call for a distance that is 12 feet short of returning to the point of beginning, and no monument is called at the closing corner. How should the surveyor treat the misclosure?

  1. Adjust the courses and distances proportionally so the traverse closes on the point of beginning. Correct answer.
  2. Hold the point of beginning and ignore the misclosure without adjustment.
  3. Reject the description as void for uncertainty.
  4. Add the 12 feet to the last course so the description closes exactly as written.

Explanation

A description that fails to close mathematically is treated as intending to return to the point of beginning, and the error is distributed among the courses. Proportional adjustment preserves the relative geometry of the parcel.

Question 39Boundary Surveying and Land Descriptions

A grantor owns a tract bounded on the east by a non-navigable lake and conveys the tract by a description that bounds on the lake. The lake subsequently recedes, exposing additional land. Who owns the exposed land under the common-law doctrine of accretion?

  1. The riparian owner, as a gradual and imperceptible addition to the shoreline Correct answer.
  2. The original grantor, because the deed did not describe the exposed land
  3. The adjoining upland owners in equal shares regardless of frontage
  4. The state, because all lake beds are held in trust for the public

Explanation

Under the doctrine of accretion, gradual and imperceptible changes in a shoreline belong to the riparian owner whose land borders the water. The addition follows the boundary as it moves with the water.

Question 40Boundary Surveying and Land Descriptions

A surveyor must interpret a deed call reading "to the old oak stump, thence S 45° E 100 feet to a pile of stone." The stump has rotted away, but the pile of stone is found and fits the remaining calls. What principle best guides the interpretation?

  1. The entire description fails because a called monument no longer exists.
  2. The remaining calls and the found monument may be used to reconstruct the position of the vanished monument. Correct answer.
  3. The vanished stump is presumed to have stood at the deed's point of beginning.
  4. The bearing and distance alone control, and the stone pile is disregarded.

Explanation

When a called monument has vanished, its position may be reconstructed from other calls, found evidence, and the testimony of the remaining monuments. The found stone pile and consistent calls supply that evidence.

Question 41Geodetic and Control Surveying

In the Oklahoma State Plane Coordinate System, which datum forms the basis for the current NAD83(2011) realization used on modern survey plats?

  1. The North American Datum of 1927, adjusted to the Oklahoma central meridian
  2. The North American Datum of 1983, realized through the 2011 national adjustment Correct answer.
  3. The World Geodetic System of 1984 as published by the National Geodetic Survey
  4. The Clarke 1866 ellipsoid referenced to the Oklahoma mean sea level datum

Explanation

Oklahoma State Plane coordinates are currently published on the North American Datum of 1983, and the 2011 realization is the adjustment in force before the modernized National Spatial Reference System replaces it. NAD27 belongs to an earlier datum and is not the basis of current NGS-published SPCS values.

Question 42Geodetic and Control Surveying

Oklahoma is divided into how many State Plane Coordinate zones, and what are they called?

  1. Three zones, designated North, Central, and South
  2. One zone covering the entire state
  3. Two zones, designated North and South Correct answer.
  4. Four zones, designated Northwest, Northeast, Southwest, and Southeast

Explanation

Oklahoma uses two State Plane zones, North and South, separated along a defined parallel so that scale distortion stays within acceptable limits. Each zone has its own projection constants and false origin.

Question 43Geodetic and Control Surveying

A surveyor measures a horizontal ground distance of 1,000.000 ft at an elevation of 2,000 ft above the ellipsoid in Oklahoma. Using an Earth radius of 20,906,000 ft, what is the approximate ellipsoid (geodetic) distance?

  1. 1,000.009 ft
  2. 1,000.096 ft
  3. 999.096 ft
  4. 999.904 ft Correct answer.

Explanation

The elevation (sea-level) reduction factor is R/(R+h), which equals 20,906,000/20,908,000 = 0.9999043. Multiplying 1,000.000 ft by that factor gives about 999.904 ft, so ground distances above the ellipsoid reduce when projected down.

Question 44Geodetic and Control Surveying

When converting a geodetic distance to a State Plane grid distance, which two corrections must be applied?

  1. Refraction correction and curvature correction
  2. Temperature correction and tension correction
  3. Convergence of meridians and arc-to-chord correction
  4. Elevation factor and scale factor Correct answer.

Explanation

Grid distance is obtained by multiplying the ellipsoid distance by the elevation factor and then by the projection scale factor. Convergence and arc-to-chord corrections apply to azimuths, not distances.

Question 45Geodetic and Control Surveying

In the Oklahoma State Plane Coordinate System, what is the scale factor along the standard parallel(s) of each zone?

  1. Slightly less than 1, increasing away from the central meridian
  2. Slightly greater than 1, decreasing toward the zone edges
  3. Variable, set by the user for each project
  4. Exactly 1.00000000 Correct answer.

Explanation

The standard parallels are lines of exact scale where the projection surface intersects the ellipsoid, so the scale factor there is exactly 1.00000000. Between and beyond the standard parallels the scale factor departs from unity.

Question 46Geodetic and Control Surveying

Which projection type is used for the Oklahoma State Plane Coordinate System zones?

  1. Lambert Conformal Conic Correct answer.
  2. Oblique Mercator
  3. Albers Equal-Area Conic
  4. Transverse Mercator

Explanation

Oklahoma's two zones use the Lambert Conformal Conic projection, which preserves shape locally and suits states with an east-west orientation. Transverse Mercator is used for states with a dominant north-south extent.

Question 47Geodetic and Control Surveying

A surveyor needs the most current published NAD83 coordinates and ellipsoid heights for a passive control mark in Oklahoma. Which NGS resource should be consulted?

  1. The NGS Data Sheet (datasheet) retrieved from the National Geodetic Survey Correct answer.
  2. The published USGS 7.5-minute quadrangle for the area
  3. The county assessor's parcel records
  4. The Oklahoma Department of Transportation county map series

Explanation

NGS Data Sheets are the authoritative source for published horizontal and vertical coordinates, including the realization and epoch. Quadrangles and county records are not authoritative geodetic sources.

Question 48Geodetic and Control Surveying

What does an epoch date such as 2010.00 associated with a published NAD83(2011) coordinate represent?

  1. The date of the survey that first observed the mark
  2. The reference time to which the coordinate is adjusted, accounting for crustal motion Correct answer.
  3. The expiration date after which the coordinate becomes invalid
  4. The date the monument was originally set in the field

Explanation

Modern NAD83 realizations are dynamic, and coordinates are published at a reference epoch so that plate motion can be accounted for. The epoch is not the monument-setting date nor an expiration date.

Question 49Geodetic and Control Surveying

A surveyor observes a GNSS baseline in Oklahoma using a network RTK service referenced to NAD83(2011) epoch 2010.00. Which statement best describes the coordinate the surveyor obtains?

  1. A coordinate on the International Terrestrial Reference Frame at the current epoch
  2. A coordinate that must be transformed to WGS84 before any use
  3. A coordinate consistent with the active reference frame, which may differ from a passive mark's published value by crustal motion Correct answer.
  4. A coordinate on the North American Datum of 1927 requiring no transformation

Explanation

Network RTK referenced to NAD83(2011) epoch 2010.00 yields coordinates in the active frame at that epoch. Passive marks published at a different epoch may differ because of crustal motion, so consistency requires accounting for the epoch difference.

Question 50Geodetic and Control Surveying

Which statement correctly describes the relationship between the Oklahoma State Plane grid azimuth and the geodetic azimuth at a point?

  1. They are always identical regardless of position within the zone
  2. They differ only by the elevation factor
  3. They differ by the convergence of the meridians plus the arc-to-chord correction Correct answer.
  4. They differ by the scale factor expressed in seconds of arc

Explanation

Grid azimuth equals geodetic azimuth minus the mapping angle (convergence) and, for lines of significant length, adjusted by the arc-to-chord correction. Distance factors do not convert azimuths.