Geography 222 The Power of Maps

...to Geog 222 Main Page and Course Description
...to Geog 222 Syllabus
...to Geog 222 Course Schedule and Lecture Outlines
...to Geog 222 Laboratory Information and Student Projects


Geog 222 Lecture Outline: Map Coordinate Systems
Update: 3/24/14

Map Locational or Coordinate Systems

Modern maps (except informal sketch maps and mental maps) are based on systematic location encompassing the entire earth (or parts of it).


But in the past...lack of an all encompassing system of locations:



Map Locational or Coordinate Systems



Four main characteristics that differentiate these coordinate systems:

1. What feature forms are the coordinate system generally used to specify?



2. What kind of geometry does the coordinate system use?


3. How much area does a coordinate system cover?


4. What are the units of measurement used?



Discuss these four characteristics in the context of five different map coordinate systems


Coordinate systems primarily used to locate POINTS

1. State Plane Coordinate System (SPCS)


2. Universal Transverse Mercator System (UTM)


3. Latitude/Longitude


Coordinate systems primarily used to locate AREAS

4. U.S. Public Land Survey System (USPLS)


5. Arbitrary Reference Grids


Review each of these and detail...

  1. How the coordinate system is defined

  2. Who uses the coordinate system and what they use it for

  3. How the coordinate system is represented on maps


Example Maps:




Coordinate Systems primarily used to locate POINTS


1. State Plane Coordinate System (SPCS)

History:



Defining SPCS: US map with zones

Coverage: 120 zones in US only running primarily east/west or north/south



Geometry: Planar




Who uses SPCS and for what?




How is SPCS shown on a USGS Topo Sheet

PROP) Delaware OH 1:24,000 quad: lower left, near township name "Concord"


This point is located as such:






2. Universal Transverse Mercator System (UTM)

History:




Defining UTM



Coverage: 60 strips (zones) around entire globe oriented north/south and numbered west to east from the international date line

Each strip...



Geometry: Planar





Who uses UTM and for what?



How is UTM shown on a USGS Topo Sheet?


PROP) Delaware OH 1:24,000 quad: lower left, near township name "Concord"


This point is located as such:






3. Latitude/Longitude

History:



Defining Longitude


Four important characteristics of longitude and meridians

1. All meridians are great circles which pass through both poles: slice the sphere in half; shortest distance between two points on the globe



2. Prime meridian arbitrary 0 degree base line meridian (Greenwich England)



3. Meridians converge at the poles



USGS Topo Quads are defined (in area covered) by longitude (width) and latitude (highth)

PROP) Delaware OH 1:24,000 Quad: At all corners of sheet




4. Longitude is measured by the time difference between greenwich and the point of interest.



Defining Latitude


Four points about latitude and parallels:

1. Only the equator is a great circle; all other parallels are not


2. Equator is the base line (0 degrees) for latitude


3. Parallels never converge


4. Latitude is measured


...In general, lat/long



Who uses Lat/Long and for what?




How is Lat/Long shown on a USGS Topo Sheet

PROP) Delaware OH 1:24,000 Topo: Lat/Long crosshair: S of Radio Tower, near "W" in Delaware


PROP) Delaware OH 1:24,000 quad: lower left corner


This point is located as such:






Coordinate Systems primarily used to locate AREAS

4. U.S. Public Land Survey System (USPLS)

History: Metes and Bounds





Defining USPLS



Township and Range System


Geometry: Planar



Who uses USPLS and for what?




How is USPLS shown on a USGS Topo Sheet






5. Arbitrary Reference Grids


Can be just about any kind of reference system that is set up for a specific map and is not connected in any way with any other map



Summary: Map Coordinate Systems

Four important aspects of map coordinate systems

  1. What feature forms are the coordinate system generally used to specify?

  2. What kind of geometry does the coordinate system use?

  3. How much area does a coordinate system cover?

  4. What are the units of measurement used?


...and five important systems...

  1. State Plane Coordinate System (SPCS)

  2. Universal Transverse Mercator System (UTM)

  3. Latitude/Longitude

  4. U.S. Public Land Survey System (USPLS)

  5. Arbitrary Reference Grids



E-mail: jbkrygier@owu.edu

...to Geog 222 Main Page and Course Description
...to krygier teaching page.
...to krygier top page.

OWU Home
OWU Geology and Geography Home