Cartographic Principles & Map Projections

Question 1

What a projected coordinate system?

Answer 1

It converts locations on the Earth’s curved surface onto a flat surface.

Question 2

What are the three types of projection?

Answer 2

Cylindrical, conical, and azimuthal/

Question 3

What are the characteristics of a cylindrical projection?

Answer 3

Can be “unrolled” into a flat plane without folding, tearing, etc.

Question 4

What is a characteristic of a conical projection?

Answer 4

It can be curved, but only in one direction.

Question 5

What kind of projection stays true to the earth’s axis of rotation?

Answer 5

Normal

Question 6

What known as a transverse projection?

Answer 6

One with a developed surface axis that runs perpendicular to the earths axis of rotation.

Question 7

What is known as a tangent projection?

Answer 7

One in which the developable surface touches, but doesn’t intersect the Earth.

Question 8

What is known as a secant projection?

Answer 8

One in which the developable surface intersects the surface.

Question 9

What are the two radians?

Answer 9

Longitude and latitude (x,y)

Question 10

How does map projection actually work?

Answer 10

Input unprotected
(lat/long), apply a pair of functions (x,y), and output a position in projected coordinates.

Question 11

How does one minimize distortions which is characteristic of maps?

Answer 11

By using compromising projections that attempt to balance properties.

Question 12

What are the three types of compromise projections?

Answer 12

ConFORMAL, equal-area, equiDISTANT

Question 13

Where is distortion seen in an equal area projection?

Answer 13

Shape

Question 14

Where is distortion seen in a conformal projection?

Answer 14

Area

Question 15

What is a Mercator projection classified as?

Answer 15

A conformal normal cylindrical projection

Question 16

Where does a Mercator projection distort?

Answer 16

At the polls where spacing of parallels increase.

Question 17

What are known as rhumb lines?

Answer 17

Lines of constant bearing

Question 18

What are the characteristics of a gnomic projection?

Answer 18

Azimuthal (causes distortion in everything), straight lines depict great circles (makes it good for aviation)

Question 19

What is a lambert conformal conic projection good for?

Answer 19

Large east-west extents in mid-latitudes, w latitudinal range less than 35 degrees.

Question 20

What applications are conformal projections best for?

Answer 20

Cadasters, topographic maps, weather, and military.

Question 21

What are equal-area projections best applied for?

Answer 21

Land-use and density/concentration.

Question 22

What kind of projections are best for tropic areas of N-S extent?

Answer 22

Cylindrical

Question 23

What kind of projections are best for mid latitude areas of E-W extent?

Answer 23

Conical

Question 24

What kind of projections are best for the polar regions?

Answer 24

Azimuthal

Question 25

What is georeferencing?

Answer 25

The process of defining position w respect to a reference frame (also known as geo coding or geolocating)

Question 26

What are the requirements of georeferencing?

Answer 26

Uniqueness (1 coord. per location), interoperability (shared meaning among users), and persistence (does not req frequent updates)

Question 27

What are the two types of metric (coordinate system) georeferencing?

Answer 27

Geographic Coordinate System (locations on a sphere) and Projected Coordinate System (locations on a plane)

Question 28

What is the Universal Transverse Mercator?

Answer 28

Not strictly a projection rather, a coordinate system based on a series of Transverse Mercator projections.

Question 29

What’s the difference between the transverse Mercator and universal transverse Mercator?

Answer 29

Transverse uses tangent lines and universal uses lines of secancy

Question 30

What are the characteristics of the UTM system?

Answer 30

Earth is divided into 60 zones with 6 degrees of longitude wide that are labeled from 1 to 60 starting from the international date line, each zone has a central n-s meridian and they are divided into letter zones

Question 31

What does the UTM coordinate system consist of?

Answer 31

Zones w their own coordinate system in meters defined by an x coordinate (wasting),a y coordinate (northing), and an origin.

Question 32

What is an origin?

Answer 32

It’s the intersection of equator and central meridian.

Question 33

What is known as a false easting?

Answer 33

When the central meridian gives an arbitrary x value of 500,000

Question 34

What is a graticule?

Answer 34

A grid of mapped latitude and longitude lines.

Question 35

What is known as geodesy?

Answer 35

The study of the shape of the earth

Question 36

What is a geoid?

Answer 36

An equi-potential gravitational surface that is not measured nor regular.

Question 37

What is known as an ellipsoid?

Answer 37

Similar to a geoid but flat and constant

Question 38

What is known as the datum?

Answer 38

The coordinate system defined by an ellipsoid positioned w respect to the earth