Basic Geodesy (Cartographic Fundamentals)

Question 1

Geodesy

Answer 1

Science of Earth measurement

Question 2

Pythagoras (6th Century B.C.)

Answer 2

Humans live on a perfect sphere

Question 3

Aristotle (4th Century B.C.)

Answer 3

Sailing ships disappeared hull first and mast last..

Question 4

Late 1600’s

Answer 4

Conclusion : the Earth is not a perfect sphere, but rather a prolate spheroid

Question 5

Issac Newton (1687)

Answer 5

Oblate spheroid

Question 6

The Graticule (Geographic Grid)

Answer 6

Combination of latitude and longitude

Question 7

Lines of Latitude (parallels)

Answer 7

Run east to west but are labeled north or south of the Equator

Question 8

Lines of Longitude(Meridians)

Answer 8

Run North to South but are labeled east or west of the prime meridian

Question 9

Reference Ellipsoid

Answer 9

a mathematically defined surface that approximates the geoid

Question 10

Worldwide used Ellipsoids

Answer 10

Geodetic reference System (GRS)1980

World Geodetic System 1984 (WGS84)

Question 11

Geoid model

Answer 11

Most precise shape of Earth, approximates mean sea level, is the shape that the surface of the oceans would take under the influence of Earth gravitation and rotation alone(no current, wind, tides, waves)

Question 12

Datums

Answer 12

Defines the size and shape of the Earth(reference ellipsoid) and some tie point that fixes the ellipsoid on the surface of Earth or the the center of Earth
(A datum also describe the origin and orientation of the coordinate system used)

Question 13

Horizontal datum

Answer 13

Specifies locations in terms of geodetic latitude and longitude computed from a reference ellipsoid

Question 14

Vertical Datum

Answer 14

determines elevation regarding the mean sea level>relates to the geoid

Question 15

NAD

Answer 15

North American Datum

Question 16

NAD27

Answer 16

Clarke 1866 Ellipsoid

Tie point at Meades Ranch (KS)

Question 17

NAD83

Answer 17

Geodetic Reference System GRS80

Tie point at the center of Earth

Question 18

Geographic Coordinate System (GCS)

Answer 18

Defines the shape of the earth>3D of the earth

Datum, ellipsoid, angular units of measure, prime meridian

Question 19

Projected coordinate systems(PCS)

Answer 19

Used to show the 3d Earth into 2D flat sheet using projection(Does not work without GCS)

Question 20

State Place Coordinate System (SPC)

Answer 20

Each zone (usually referred by the name of the State) is assigned its own coordinate system and projection

Question 21

Universal Tranverse Mercator (UTM) Coordinate System

Answer 21

60 six degree zones elongated in North/South direction