1What is the science of measuring and mapping the Earth's surface, including its external gravity field?
Geodesy
2Who gave the classical definition of geodesy?
Helmert
3What does the word "geodesy" mean?
Dividing the Earth
4What broader discipline includes surveying, mapping, geodesy, photogrammetry, remote sensing and information science?
Geomatics
5What are the three specific concerns of geodesy?
Earth's size and shape, its gravity field and magnitude, and reference systems and frames
6What are the four objectives of geodesy?
Determine accurate positions of points, study the gravity field, define the Earth's shape and size, and determine geodynamic phenomena
7Which branch of geodesy deals with the 3D geometric elements of the ellipsoidal model and the location of points relative to it?
Geometrical geodesy
8Which branch of geodesy studies gravity, mass distribution, equipotential surfaces and the geoid?
Physical geodesy
9Which branch of geodesy deals with artificial satellite trajectories and processing satellite signals to find a receiver's position?
Satellite geodesy
10Which branch of geodesy finds positions and directions by observing stars and celestial objects?
Geodetic astronomy
11Who first published the theory of least squares in 1806?
Adrien-Marie Legendre
12Who used least squares as early as 1794 to determine an asteroid's orbit?
Carl Friedrich Gauss
13Which method identifies the most reliable results from inconsistent observations?
Least squares method
14Which asteroid's orbit did Gauss compute using least squares?
Ceres
15What is Gauss's 1828 work that gave a solution for spheroidal triangles?
Theorema Egregium
16What is the 1822 conformal projection of the ellipsoid onto a plane by Gauss called?
Gauss conformal projection
17Which method by Helmert finds the best-fitting ellipsoid by minimizing the sum of squared vertical deflections?
Area method
18Which equipotential surface serves as the reference for the height datum?
Geoid
19Which formula is used to determine the geoid from gravity observations?
Stokes' integral formula
20Who developed in 1849 the theorem for determining the geoid from terrestrial gravimetric observations?
Sir George Gabriel Stokes
21Who published Théorie de la figure de la Terre in 1743?
Alexis Clairaut
22Whose 1945 theorem gives geodetic height directly from surface gravity without reducing to the geoid?
Mikhail Molodensky
23What event in 1957 marked the beginning of satellite geodesy?
The launch of the first artificial satellite (Sputnik I)
24Which satellite technique measures the geoid undulation of seawater?
Satellite radar altimetry
25Which organization is responsible for the advancement of geodesy?
Global Geodetic Observing System (GGOS)
26Which non-governmental scientific organization, founded in 1919, promotes the study of the Earth and its space environment?
International Union of Geodesy and Geophysics (IUGG)
27Which association promotes scientific cooperation and research in geodesy worldwide?
International Association of Geodesy (IAG)
28Who imagined the Earth as a disk surrounded by oceans?
Homer (Iliad) and Thales of Miletus
29Who first proposed that the Earth is spherical (c. 580-500 B.C.)?
Pythagoras and his school
30Which astronomer worked out a geometric method for the ratio of Sun-Earth to Moon-Earth distances?
Aristarchus of Samos
31What are Aristotle's proofs of a spherical Earth?
The round shadow on the moon during eclipses, new stars appearing when travelling north-south, and falling objects heading to a common center
32Who is credited with being the first to determine the Earth's size (230 B.C.)?
Eratosthenes
33What method did Eratosthenes use to determine the Earth's size?
Arc measurement, using the meridian arc between two cities and the angle between the plumb line and the sun's ray
34Which two cities did Eratosthenes use?
Syene and Alexandria
35What Earth radius did Eratosthenes obtain?
About 6,300 km
36What is the modern mean radius of the Earth?
About 6,370 km
37Which Greek astronomer's degree-measurement result was 11% too large?
Poseidonius of Apameia
38Who established the geocentric world system and wrote the Almagest and Geographike Hyphegesis?
Claudius Ptolemy
39Who conducted an astronomic-geodetic survey in China around 725 A.D.?
Nankung Yueh and I-Hsing
40Who measured a 2-degree meridian arc using ropes around 827 A.D.?
The Arabs
41Who measured the Paris-Amiens arc using a wagon wheel?
Jean Fernel
42Which indirect method replaced tedious direct length measurements after the telescope was applied?
Triangulation
43Who conducted the first triangulation (1614/15) between Bergen op Zoom and Alkmaar?
Willebrord Snell van Royen (Snellius)
44Who measured the meridian arc through Paris in 1669-1670 and was first to use crosshairs in a telescope?
Jean Picard
45Who achieved the transition from a geocentric to a heliocentric system?
Nicolaus Copernicus
46Who formulated the laws of planetary motion?
Johannes Kepler
47Who established the fundamentals of mechanical dynamics?
Galileo Galilei
48Who observed Jupiter's flattening at the poles in 1666?
Jean-Dominique Cassini
49Who was convinced that the Earth is flattened at the poles, along with Huygens?
Isaac Newton
50Which Dutch scientist calculated an Earth flattened at the poles?
Christiaan Huygens
51What Earth shape did Cassini's arc measurements suggest, with a flattening of -1/95?
Elongated at the poles
52Who conducted the Lapland arc measurement in 1736-1737?
Maupertuis and Clairaut
53What flattening resulted from the Lapland arc measurement?
1/304
54Who derived a flattening of 1/330 from 15 gravity values in 1799?
Pierre-Simon Laplace
55Who refined the "figure of the Earth" as the geoid and a reference ellipsoid?
Gauss and Bessel
56Who established geodesy as a proper science?
Friedrich Robert Helmert
57What instrument was used for gravity observations in the 18th century?
Pendulum
58What method was used to establish vertical control networks from 1880 onward?
Geometric leveling
59Which 1875 event defined the meter with a standard meter bar?
International Meter Convention in Paris
60Which 1884 event adopted the Greenwich meridian as the origin of longitude?
International Meridian Conference in Washington D.C.
61Who detected polar motion in 1884/85?
F. Kustner
62Who first observed Earth tides (1889-1893)?
E. von Rebeur-Paschwitz
63Which global positioning system was developed in the 1980s?
NAVSTAR GPS
64What do you call a positive vertical angle?
Angle of elevation
65What do you call a negative vertical angle?
Angle of depression
66What is the complement of the vertical angle called?
Zenith angle
67What equipment is used for angular measurement?
Groma, sextant, telescopes, theodolite and total station
68What equipment is used for distance measurement?
Measuring chain, steel tapes, odometers, electronic distance meters and GNSS techniques
69What is generally regarded as the most fundamental of all surveying measurements?
Distance measurement
70Which technique determines a point's position by observing celestial bodies?
Astronomical measurement
71What are the three astronomical coordinates and directions?
Astronomical longitude, latitude and azimuth
72What is the plane containing the Greenwich observatory called?
The reference meridian (prime or zero meridian)
73Which leveling method uses horizontal distance, vertical angle and instrument heights?
Trigonometric leveling
74Which GNSS positioning method, classified by observed values, uses code-based ranges?
Pseudorange positioning
75Which GNSS positioning method uses the phase of the satellite signal?
Carrier phase positioning
76Which GNSS positioning mode determines the position of a single receiver without a reference?
Absolute positioning
77Which GNSS positioning mode determines position relative to another receiver?
Relative positioning
78In GNSS, what is positioning called when the receiver's position changes with time?
Kinematic positioning
79In GNSS, what is positioning called when the receiver's position stays unchanged during observation?
Static positioning
80Which type of gravimetry determines the gravity value at a defined point?
Absolute gravimetry
81Which type of gravimetry determines the difference in gravity between two points?
Relative gravimetry
82Which type of gravimetry uses an aircraft, gravimeter, GPS, altimeter and attitude devices?
Airborne gravimetry
83What are the four satellite gravimetry techniques?
Ground tracking of satellites, satellite-to-satellite tracking, satellite gravity gradiometry and satellite altimetry
```