Measuring and Modeling Earth: Coordinate Systems

Question 1

Coordinate system can either be….

Answer 1

2D or 3D

Question 2

Cartesian VS Polar

Answer 2

Cartesian: 2 and 3 dinmensional coordinate systems based on orthogonal axes. (lines intersect at right angles)
- Positions in cartesian coordinate systems, but 2 and 3 D are communicated with 2 or 3 numbers indicating distances along the 2 or 3 axis.

Polar: Systems based on angle from baselines.
- Positions in polar coordinate systems both 2 and 3D are communicated with 2 or 3 numbers and one of which indicates a dustance along an axis while the remaining numbers indicate a distance in degrees around an origin.

Question 3

Cartesian VS Polar summed up.

Answer 3

Cartesian shapes: - Lines intersect at 90 degrees
- measuring distance along axis

Polar: Measure distance away from prigin and rotation away from that origin.

Question 4

3 types of cartesian coordinates:

Answer 4

1. ) 2-D cartesian points
2. ) 2-D cartesian lines
3. ) 2-D cartesian line length

Question 5

What is easier to calculate? A 2-D cartesian coordinate system or a 3D?

Answer 5

2D

Question 6

2-DCartesian coordinate system

Answer 6

A two-dimensional, planar coordinate system in which horizontal distance is measured along an x-axis and vertical distance is measured along a y-axis. Each point on the plane is defined by an x,y coordinate.

Question 7

3-D cartesian coordinates

Answer 7

Locations are indicated by 3 values corresponding to distances along the three orthogonal axes.

Question 8

3-D polar coordinates

Answer 8

Locations are indicated by one distance value and 2 angle values.

Question 9

What do the angles represent in a 3-D polar coordinate system

Answer 9

1. ) deviation away from the origin (X) axis and

2. ) away from the baseline surface (2-D plane deined by X,Y axis) around the origin of the point.

Question 10

What is an axample of 3-D polar coordinate system?

Answer 10

Lat and longitude!

Question 11

Difference betwen a 3-D polar coordinate system and a 2-D polar coordinate system?

Answer 11

2-D consists of a single basleine with locations indicated by a distance along the baseline away from the origin.

3-D is indicated by one distance and 2 angle values.

Question 12

Difference between a 2-D cartesian coordinate system and a 3-D cartesian coordinate system?

Answer 12

2-D locations are indicated by pairs of numbers that are related to distance away from an origin (share by 2 axis) along the 2 axes,. Coordinates of a point location are indicated by their distance from perpendicular lines intersecting at the coordinate systems origin.
3-D locations are indicated by 3 values corresponding to distances along the three orthogonal axes.

Question 13

Types of Global reference systems: (5)

Answer 13

1. ) Latitude and longitude
2. ) earth centered, earth fixed (ECEF)
3. ) Universal transverse mercator (UTM)
4. ) Military Grid Reference System (MGRS)
5. ) World Geographic Reference System (GEOREF)

Question 14

What is the most commonly used Global reference system?

Answer 14

Longitude and Latitude

Question 15

What are the reference planes used in longitude and latitude?

Answer 15

• The Prime Meridian
  and
• The Equator

Question 16

The geodetic latitude of a point is

Answer 16

the angle between the equatorial plane and a line normal to the reference ellipsoid.

Question 17

The geodetic longitude of a point is

Answer 17

the angle between a reference plane and a plane passing through the point, both planes being perpendicular to the equatorial plane.

Question 18

The geodetic height at a point is

Answer 18

the distance from the reference ellipsoid to the point in a direction normal to the ellipsoid.