Geodesy Board Practice Exam

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• Which term describes the height above the geoid measured along the local vertical?
• What is a GNSS baseline?
• In which theorem are the angles A, B, and C of a spherical triangle equal to the corresponding angles of a plane triangle whose sides are a, b, and c, each increased by one-third the spherical excess of the triangles?
• What is the published azimuth of the line AJ10-AJ24?
• Which pair of time scales are involved in the equation of time?
• The sum of the squared residuals of four measurements of a geodetic baseline is 0.0188. What is the probable error of the baseline?
• What is the purpose of datum transformations in practice?
• Which parameter is used to correct the difference between grid length and geodetic length along a line?
• In height conversion, ellipsoidal height h equals orthometric height H plus geoid undulation N.
• For observers on the equator, which statement is true?
• Under DAO 2007-29, which division shall calibrate and register UAS used for land surveying?
• Using the weighted value method, what is the most probable difference in elevation between BM 12 and BM 13?
• What is the acceptable minimum accuracy in image classification?
• In the celestial sphere, which term refers to the point directly below the observer?
• Identify the pair of projections and their typical applications.
• What are NAD27 and NAD83, and how do they differ?
• In the published accuracy statement of an electronic total station, the value 0.2 mm in ±(0.2 mm + 5 ppm) refers to which type of constant?
• What does a nonzero covariance between coordinates indicate in a network adjustment?
• In the horizon coordinate system, which pair of values defines the position of a celestial object?
• In which projection are great circles represented as straight lines in all aspects?
• If BM 12 has an elevation of 27.048 meters and is higher than BM 13, what is the most probable elevation of BM 13?
• Name common geodetic datums used in the United States for mapping and positioning.
• For a UAS lot survey, the hard copy of the ortho-image covering the entire project must be printed not exceeding 54x54 cm.
• What is the name of the angle between the horizon and the polar axis?
• Which surface is defined as mean sea level extended through the continents and used as a reference for orthometric heights?
• An example of the measurement accuracy notation used for a baseline observation is which of the following?
• The correct formula to solve the coefficient q for grid to geographic conversion is:
• Which formula expresses orthometric height H in terms of ellipsoidal height h and geoid undulation N?
• Which instrument's accuracy specification is given as 5 mm + 5 ppm in the distance example?
• Redundancy in a geodetic network refers to what?
• The equation of time expresses the difference between LAT and LMT.
• In GNSS surveying, the essential direct measurement must be with the satellites rather than the stations in the project network; this is described as line of sight to satellites and control.
• A method of establishing a geodetic control surveys consisting of connected triangles or polygons where all _____ are measured is called _____
• What is the term for the setting that stops GNSS receivers from using satellites near the horizon?
• Root mean square expresses the ______ of point measurements.
• The free-air gravity anomaly height correction for every meter above sea level is ______ mgal.
• What are grid coordinates in a map projection?
• What is variance component estimation (VCE) used for in least squares adjustment?
• When the geoid coincides with the ellipsoid at the datum origin, the normal to the ellipsoid is aligned with which line at the datum origin?
• In geographic coordinate systems, what is the central meridian?
• In real-time network RTK GPS surveys, network corrections are provided by several permanently operating reference stations.
• What is a 7-parameter Helmert transformation used for in datum shifts?
• In GNSS, a pseudo-range measurement is biased by clock error of which component?
• Geoid undulation N is defined as the height of the geoid above the ellipsoid.
• How many longitudinal zones does the UTM system divide the globe into?
• What is the name of the great circle that passes through the nadir and the south celestial pole?
• Which statement about the Mean Sun's motion regarding right ascension is correct?
• What is the purpose of ambiguity resolution in RTK?
• When geoid and ellipsoid coincide at a datum origin, the deflection and the ______ and the separation between the ellipsoid and geoid become ______ at the origin.
• ______ gravity anomaly refers to small regional variations in the Earth's gravity field resulting from density variations in underlying rocks.
• In Philippine geodesy, the Vigan Datum is best described as which of the following?
• The relationship between geocentric latitude ψ and reduced latitude β is which of the following?
• In a conventional GNSS RTK survey, the data transfer from the base to the rover can be made either through a ______ or a telephone link.
• What do the seven Helmert parameters represent in a coordinate transformation?
• Which database model stores data in a tree-like structure with parent records linked to a root?
• The distance from the origin to one of the ellipse's focus is
• GNSS____ resolution may be accomplished by interchanging the antenna and receiver assemblies between two stations.
• Inverse flattening is defined as the reciprocal of what quantity?
• Describe the local tangent plane concept and when it is appropriate to use it.
• Least squares is a method of adjusting observations in which the sum of the squares of which quantity is minimized?
• An image with 11-bit radiometric resolution can contain pixel values within the range _________.
• A 2-km baseline is measured with an electronic total station. If the instrument accuracy is 5 mm + 5 ppm, what is the accuracy of the measured distance to the nearest thousandth?
• Which statement about geographic to grid conversion is NOT true?
• Which statement about the radii of curvature on a reference ellipsoid is true?
• Atmospheric refraction tends to diminish the effect of earth curvature by approximately _______ per cent.
• Leveling-based datums versus gravimetric datums: which statement is correct?
• Which radiometric correction option is not a standard correction used to adjust radiance due to atmospheric conditions?
• The zero-point for ______ is the vernal equinox.
• How does satellite elevation influence the severity of tropospheric delay?
• Why is weighting important in least squares adjustments, and what does weight represent?
• The _____ maintains the geodetic control network of the Philippines.
• Which observation type provides centimeter- to millimeter-level precision only after resolving integer ambiguities?
• The GNSS measured distance is called a pseudo-range because it has a constant bias error due to the clock error of the ______.
• If ellipsoidal height is 50 m and geoid undulation is 5 m, what is the orthometric height?
• Orthometric height is defined as height above which surface?
• What is the primary purpose of conducting a network adjustment in surveying?
• Grid length differs from geodetic length by the amount of a correction based on the ______ for the given line.
• Which height is commonly obtained from GPS measurements?
• Which statement about the lengths of solar and sidereal years is true?
• The ratio 1/133000 in the distance accuracy example represents which type of accuracy?
• Which term denotes the great circle that passes through the nadir and the south celestial pole?
• In the equation h = H + N, what does H stand for?
• Which set of factors does NOT influence GNSS observation time?
• Free-air anomaly is the difference between the _____ gravity and theoretical gravity at a point.
• Which statement about meridian convergence corrections in survey practice is NOT true?
• What does the geoid represent within geodesy?
• Which statement about the World Polyconic Grid is true?
• When LAT equals LMT, which is true?
• What is the adjusted value of angle D in the least-squares adjustment of the angles?
• In GNSS, ephemeris data describe satellite positions as a function of which variable?
• The compression of a circle along a diameter to form an ellipse or ellipsoid of revolution is described by which term?
• How does the covariance matrix describe a post-adjustment network's uncertainty?
• What is carrier-phase ambiguity, and why is its resolution important?
• Name the two main GNSS observation types and summarize their characteristics.
• Define ellipsoidal height and orthometric height, and give their relationship.
• How are covariance and correlation used in evaluating geodetic measurements?
• The LMB through the ____________ shall calibrate and register UAS used for land surveying pursuant to Section 22, DAO No. 2007-29.
• A 2.5-km baseline is measured with an electronic total station. If the vendor's accuracy specification of the instrument is ± (5mm + 2ppm).calculate the accuracy of the measured distance to the nearest thousand.
• In GNSS, which components make up PNT?
• Why are a priori observation weights used in adjustment of GNSS data?
• In ellipse geometry, the first eccentricity e is defined as e = sqrt(1 - (b^2 / a^2)). Which option correctly shows this relation?
• Using the least squares method, determine the correction, in millimeters, to the field difference in elevation along route 2.
• In both geocentric and geodetic coordinate systems, the geodetic longitude λ is equal to which expression?
• What is differential GNSS (DGPS) and its typical accuracy improvement?
• The spectral region of the electromagnetic radiation which passes through the atmosphere without much attenuation is known as:
• In least squares adjustment, what is the impact of adding constraint equations?
• Which technique involves transmitting a signal from a ground station, reflecting off retro-reflectors on satellites, and receiving back at the station?
• How would you differentiate a coordinate reference system from a map projection?
• Which of the following equations is/are incorrect for the given grid conversion formulas?
• What term describes the spectral region that experiences minimal atmospheric attenuation?
• A least squares equation expressing that the three measured angles of a triangle must equal 180 degrees plus the spherical excess of the triangle is known as which type of equation?
• Which statement describes a geocentric datum?
• List common error sources in leveling surveys.
• Which grid system was the first used in the Philippines and predecessor of UTM?
• The equation of time equals which difference of times?
• Which statement correctly differentiates vertical datum from a height system?
• What is the map called where geographic areas are distorted in proportion to an attribute such as population?
• At the equator, which radius is equal to the semi-major axis length?
• GNSS multipath refers to what phenomenon, and why does it matter for accuracy?
• What is the tropospheric delay, and how does elevation affect it?
• In the meridian radius of curvature formula, the denominator is raised to which exponent?
• In a set of repeated measurements, the root mean square mainly reflects the measurement's ______.
• In leveling, a point is defined as the location where a backsight on a leveling rod is taken from one instrument station and a foresight is taken to the next instrument station. Which term describes that point?
• The relationship between geodetic latitude Φ and reduced latitude β is which of the following?
• The GPS-derived height of a control point is 56.439 meters, while the orthometric elevation of the same point is 8.795 meters. Determine the separation between the ellipsoid and the geoid at the location of the control point.
• ______ in a geodetic leveling instrument exists when the plane of the image and the plane of the cross-hairs do NOT coincide, and should be eliminated by _____ the objective, eyepiece, or both.
• Define a closed traverse and how misclosures are assessed.
• Distinguish geodetic coordinates from grid coordinates.
• A geodetic traverse starts at a point with a given position and with a known ______ to another point and then ______ are measured between a series of survey points.
• The forward and back azimuths of a geodetic line do not differ by exactly 180 degrees due to the _____.
• The radius of curvature of the ellipsoid varies with latitude and the shortest lies at the ______.
• The free-air anomaly is defined as the difference between observed gravity and which gravity value at a point?
• What is the primary goal of precise geodetic leveling, and what uncertainty is typically achieved?
• The equation of time relates Local Apparent Time to Local Mean Time by which quantity?
• When constructing an ellipse, the length of the string is
• What is the rate of change in latitude per year, in centimeters, for the PRS92 station ZGN-6 between 1990 and 2010?
• Grid azimuth is the same as geodetic azimuth only when the point of observation falls on the _______ meridian.
• Which datum is commonly used with State Plane Coordinate Systems in the United States?
• The radius of curvature of the prime vertical N is equal to which expression?
• For an 11-bit radiometric image, what is the maximum pixel value?
• Which of the following best describes a property of the Mean Sun?
• Which of the following statements are true? A) 365.25 solar days in a year. B) 366.25 sidereal days in a year. C) 364.25 sidereal days in a year. D) Both A and B.
• The angle in the plane of projection between a straight line and the central meridian of a rectangular coordinate system is Called _______ azimuth.
• In the equation h = H + N, what does N stand for?
• In a least-squares adjustment of three measured horizontal angles, what is the adjusted value of angle A?
• The azimuth measured in map grid coordinates is known as which type of azimuth?
• The relationship between geocentric latitude ψ and geodetic latitude Φ is which of the following?
• Which two times define the equation of time?
• Which statement describes the Mean Sun's right ascension behavior?
• Define precise point positioning (PPP) in GNSS.
• What is the purpose of the zone-based false origin in UTM?
• There is a need for the ____ correction in transforming geodetic to grid azimuths because the geodetic line is a curved line when projected onto a plane.
• Height is the distance measured along a _____ between a point on the earth's surface and a reference surface.
• What mathematical contrivance is used to characterize local distortions due to map projection?
• Which statement best describes a 7-parameter Helmert transformation in datum shifts?
• Which of the following values is most commonly used as the inverse flattening?
• Geodetic azimuth in the Philippines is reckoned from which direction?
• Differentiate GPS time, International Atomic Time (TAI), Coordinated Universal Time (UTC), and Terrestrial Time (TT).
• Global navigation satellite systems enable receivers to determine their location using time signals transmitted along a line of sight by radio from satellites.
• Which process reduces the number of points in a polyline while preserving its overall shape?
• Which term describes a map that emphasizes a single data theme such as population, often using color or symbols?
• What is the primary purpose of generalization in map making?
• The equation of time is the difference between which two times?
• What differentiates a geocentric datum from a local datum?
• What is the semi-major radius of Clarke's ellipsoid of 1866 in meters?
• Which of the following is not a type of radiometric correction used in image processing when there is interference with the radiance measured by an instrument?
• In carrier-phase GNSS observations, what is a cycle slip?
• What are false easting and false northing in map projections?
• What is the purpose of robust or outlier-tolerant least squares?
• In route planning, what analysis determines the path of least impedance between two points considering topography and travel restrictions?
• Which statement best describes the primary advantage of precise point positioning (PPP) in GNSS processing?
• Which statement correctly describes GPS time relative to UTC?
• Which of the following is defined as the first eccentricity of an ellipse?
• What is geoid undulation N, and how is it used in height conversion?
• Which term describes the bearing measured from north in the reverse direction of a line, as used in grid length corrections?
• Which statement best describes a priori observation weights?
• The radius of curvature in the meridian M is equal to which expression?
• In a post-adjustment network, what does the standard deviation of a coordinate correspond to?
• Grid azimuth equals geodetic azimuth when the observation lies on the central meridian.
• At the datum origin where geoid and ellipsoid coincide, the vertical separation between the two surfaces is what value?
• In spherical geometry, the sum of the three interior angles of a spherical triangle is greater than 180 degrees by the spherical excess. This statement describes which relation?
• As the Sun moves counterclockwise relative to the fixed stars, which coordinate is continuously increasing?
• Which statement about the Mean Sun is accurate?
• How does a coordinate system orientation influence a transformation?
• The correct formula to solve the coefficient p for geographic to grid conversion is:
• What is the rate of change in longitude per year, in centimeters, for ZGN-6 between 1990 and 2010?
• Authalic map projections such as the Sinusoidal projection and the Gall-Peters projection show the correct sizes of countries relative to each other but distort _________.
• Which statement is true about the Mean Sun according to the material?
• In a weighted-value adjustment of four survey routes, Route 1 is assigned a weight value of 1. What is the summation of the weights for all four routes?
• If Local Apparent Time equals Local Mean Time, the equation of time is:
• What is WGS84, and where is it used?
• What is the ionospheric delay, and how is it mitigated in GNSS?
• What is UTM in geodesy?
• What is ITRF, and why is it important for global geodesy?
• If the traverse had 12 occupied stations, what is the order of the traverse accuracy level?
• In the expression ±(0.2 mm + 5 ppm), the 5 ppm term is distance-dependent.
• Unlike conventional real-time kinematic surveys which use a single base station, real-time network RTK GPS surveys use several base stations mounted where?
• In least squares adjustment, which statement best describes a residual?
• A 200-meter baseline distance is measured with an electronic total station. If the vendor's accuracy specification of the instrument is ±(5mm + 2ppm), the precision of the measured distance relative to the baseline is closest to which value?
• What is the primary purpose of a geodetic datum?
• If the azimuth error of closure for the traverse is required in seconds, what is the error?
• Why is error propagation important when transforming coordinates between datums or projections?
• An authalic radius is the radius of a hypothetical perfect sphere which has the same surface ______ as the reference _______.
• Which instrument component is used to provide a stable base for positioning a surveying instrument on site?
• Which data condition makes robust least squares most beneficial?
• If ellipsoidal height h equals 100 meters and geoid height N equals 30 meters, what is the orthometric height H?
• In least-squares adjustment, the quantity whose squares are minimized is the residuals.
• Which of the following best describes the geoid?
• What is the total shift of the station coordinates from date of establishment up to re-observation, in meters? Assume 1" equals 30 meters.
• In a GNSS network, what does the baseline represent?
• Ephemeris data describe satellite positions as a function of time.
• Some GNSS applications include the following: I. surveying II. mapping III. navigation IV. vehicle tracking.
• Which condition is part of the Gauss-Markov assumptions ensuring the least squares estimator is BLUE?
• Which term describes a star that never sets for a given latitude due to proximity to a celestial pole?
• What does the Gauss-Markov theorem tell us about least squares estimators?
• In the celestial sphere, which term refers to the point directly beneath the observer?
• What is the role of cycle-slip detection in GNSS network processing?
• What is ellipsoidal height h in relation to the reference ellipsoid?
• In GNSS surveying, the direct _____ has to be with the satellites and not with the stations in the project ______network.
• In classical triangulation, the procedure for first-order accuracy positioning requires how many directions?
• In the hour angle system, the complementary angle of polar distance is called ______.
• Which statement best describes the difference between RTK and standard DGPS in terms of corrections and ambiguity resolution?
• What is the purpose of including constraint equations in a least squares adjustment?
• Geoid undulation, N, represents the separation between the ellipsoid and the geoid.
• GNSS observation time depends on which factors?
• Which measurement is the primary focus in trilateration surveys?
• Distinguish between an ellipsoid and the geoid.
• In image classification, which method yields higher accuracy when the classes in the image match on-ground land-use patterns?
• Which of the following combinations will NOT define an ellipse?
• Very long-range interferometry involves the simultaneous measurement of the times of signals from very distant astronomical objects such as ______.
• Using the least squares method, determine the correction, in millimeters, to the field difference in elevation along route 1.
• In the same angle adjustment, what is the adjusted value of angle C?
• In the horizon coordinate system, which two quantities define the position of a celestial object?
• Which statement correctly describes the typical magnitude of the coefficients p and q in grid conversions?
• The angle between the equatorial plane and a line joining a point on the ellipsoid to the center of the ellipsoid is called ____ latitude.
• Which of the following statements is a property of the Mean Sun?
• Which equation correctly relates reduced latitude β to geodetic latitude Φ?
• The Mean Sun property: What path does it move along?
• Using the three routes, what is the adjusted difference in elevation between BM 34 and BM 35, in meters?
• A star that never sets below the horizon for a given latitude due to near-pole position is called what?