Chapter 2 - Where in the Geospatial World Are You?

Question 1

datum

Answer 1

a reference surface of Earth

Question 2

ellipsoid

Answer 2

a model of the rounded shape of Earth

Question 3

geoid

Answer 3

a model of Earth using mean sea level as a base

Question 4

geodesy

Answer 4

the science of measuring Earth’s shape

Question 5

NSRS

Answer 5

the National Spatial Reference System, the consistent coordinate system for the United States

Question 6

NAD27

Answer 6

the North American Datum of 1927

Question 7

NAD83

Answer 7

the North American Datum of 1983

Question 8

NATRF2022

Answer 8

the North American Terrestrial Reference Frame of 2022, which will replace NAD83

Question 9

WGS84

Answer 9

the World Geodetic System of 1984 datum (used by the Global Positioning System)

Question 10

datum transformation

Answer 10

the process of changing measurements from one datum to measurements in another datum

Question 11

geographic coordinate system (GCS)

Answer 11

a set of global latitude and longitude measurements used as a reference system for finding locations

Question 12

latitude

Answer 12

imaginary lines on a global north and south of the Equator that serve as a basis of measurement in GCS

Question 13

Equator

Answer 13

the line of latitude that runs around the center of Earth and serves as the 0 degree line from which to make latitude measurements

Question 14

longitude

Answer 14

imaginary lines on a globe east and west of the Prime Meridian that serve as a basis of measurement in GCS

Question 15

Prime Meridian

Answer 15

the line of longitude that runs through Greenwich, England, and serves as the 0 degree line of longitude from which to base measurements

Question 16

degrees, minutes, and seconds (DMS)

Answer 16

the measurement system used in a GCS

Question 17

decimal degrees (DD)

Answer 17

the fractional decimal equivalent to coordinates found using degrees, minutes, and seconds

Question 18

great circle distance

Answer 18

the shortest distance between two points on a spherical surface

Question 19

time zones

Answer 19

a method of measuring time around the world, created by dividing the world into subdivisions of longitude and relating the time in each subdivision to the time in Greenwich, England

Question 20

International Date Line

Answer 20

a line of longitude that uses the 180th meridian as a basis (but deviates away from a straight line to accommodate geography)

Question 21

map projection

Answer 21

the translation of locations on the three-dimensional (3D) Earth to a two-dimensional (2D) surface

Question 22

Universal Transverse Mercator (UTM)

Answer 22

a grid system that locates coordinates across the globe

Question 23

UTM zone

Answer 23

one of the 60 divisions of the world set up by the UTM system, each zone being 6 degrees of longitude wide

Question 24

easting

Answer 24

a measurement of so many units east (or west) of some principal meridian

Question 25

northing

Answer 25

a measurement of so many units north (or south) of a baseline

Question 26

false northing

Answer 26

a measurement made north (or south) of an imaginary line such as is used in measuring UTM northings in the southern hemisphere

Question 27

false easting

Answer 27

a measurement made east (or west) of an imaginary meridian set up for a particular zone

Question 28

United States National Grid (USNG)

Answer 28

a grid system for identifying locations in the United States

Question 29

State Plane Coordinate System (SPCS)

Answer 29

a grid-based system for determining coordinates of locations within the United States

Question 30

SPCS2022

Answer 30

the version of the State Plane Coordinate System developed as part of the modernization process of the NSRS

Question 31

SPCS zone

Answer 31

one of the divisions of the United States set up by the SPCS