CTS 11 Orienteering
5.2 Latitude and Longitude and the UTM Grid System / TIME
1 period (45 minutes)
WHAT TEACHING METHOD IS SUITABLE FOR THIS PERIOD?
The Guided Discovery Method is best suited for this lesson.
WHAT MATERIAL DO I NEED? / WHAT MATERIAL DO THE CADETS NEED?
1. Local Area Map (overhead slide if possible) / 1. Handout – Local Area Map
WHAT SHOULD THE CADET BE ABLE TO PERFORM AT THE END OF THE PERIOD? / WHAT INFORMATION WILL BE PASSED ON TO THE CADE CADETS IN THIS PERIOD?
The cadet shall demonstrate:
  1. an understanding of the lines of latitude and longitude;
  2. an ability to differentiate between lines of latitude and longitude;
  3. an ability to read from a line of latitude and a line of longitude; and
  4. an ability to determine a grid reference for a point on a map.
/ The main teaching points are:
  1. the purpose of lines of latitude and longitude;
  2. the proper use of lines of latitude and longitude; and
  3. determining grid references using lines of latitude and longitude.

INTRODUCTION
WHAT?
WHY?
EXPECTATIONS
TEACHING POINTS

Map Reference Coordinate Systems

Two commonly used reference systems used on maps are “latitude and longitude” and Universal Transverse Mercator or UTM. The UTM system is used on topographic maps and we will discuss that system in later lessons.

“Latitude-Longitude” is a grid coordinate system where the imaginary lines are referenced to angular measurementstaken relative to the polesand equator of the earth. Lines of latitude on a map run east-west. Lines of longitude on a map run north-south.

Latitude and Longitude (lat-lon) are measured in degrees. To achieve better accuracy, one degree can be divided into 60 minutes just like an hour is divided into 60 minutes. Again like time, one minute of latitude or longitude can be divided into 60 seconds. Latitude is also divided into north and south. Longitude is divided between east and west. A grid coordinate in the lat-lon system is given using the latitude first and the longitude second.

As an example, the exact location of the cadet centre is as follows:

43° 35’ 10” N 79° 43’ 00” W

Latitude is the angular position of a circle, parallel to the equator, which would intersect a line running from the centre of the earth at an angle above or below the equator. To illustrate then, the equator is then at 0° north latitude, Mississauga is about halfway between the equator and the North Pole at about 43° north latitude and the North Pole is at 90° north latitude. Lines of latitude therefore range from 90° north latitude to 90° south latitude with the equator in the middle at 0°

Figure 1. Line of Latitude at an Angle North Of the Equator.

Longitude is the angular position of a half circle, perpendicular to the equator, which would run from the north pole to the south pole. The Prime Meridian is an imaginary north-south line, running from pole to pole, that runs through the town of Greenwich,England. The Prime Meridian is considered to be 0 degrees longitude. Lines of longitude range from 180° east longitude to 180° west longitude. Mississauga is about 80° west longitude.

Figure 2. Line of Longitude at an Angle West Of the Prime Meridian.

Figure 3. The Equator and Prime Meridian with respect to the Earth’s Continents

Any position on the surface of the earth can be located with a latitude and longitude coordinate. Normally the latitude coordinate is given first followed by the longitude coordinate (see the following list of cities).

City / North Latitude / West Longitude
Degrees / Minutes / Degrees / Minutes
Calgary, Alba., Can. / 51 / 1 / 114 / 1
Edmonton, Alb., Can. / 53 / 34 / 113 / 28
Kingston, Ont., Can. / 44 / 15 / 76 / 30
London, Ont., Can. / 43 / 2 / 81 / 34
Montreal, Que., Can. / 45 / 30 / 73 / 35
Moose Jaw, Sask., Can. / 50 / 37 / 105 / 31
Nelson, B.C., Can. / 49 / 30 / 117 / 17
Ottawa, Ont., Can. / 45 / 24 / 75 / 43
Quebec, Que., Can. / 46 / 49 / 71 / 11
St. John, N.B., Can. / 45 / 18 / 66 / 10
Toronto, Ont., Can. / 43 / 40 / 79 / 24
Vancouver, B.C., Can. / 49 / 13 / 123 / 06
Victoria, B.C., Can. / 48 / 25 / 123 / 21
Winnipeg, Man., Can. / 49 / 54 / 97 / 7

Table 1. Latitude and Longitude of Major Canadian Cities

On a globe the lines of latitude are equally spaced (parallel to each other). The lines of longitude are widest at the equator and converge at the north and south poles. On a Mercator projection map, the lines of longitude are shown as parallel. This means that as you move north or south away from the equator, the east west scale of the map is constantly increasing. At the equator the scale is 1:1 and at the North Pole the scale is 1: infinity. We will deal more with this in the lesson on Contour and Distance.

On a UTM map, the north-south lines are parallel and the east-west lines are also parallel but unlike the standard Mercator projection, the distances shown do not increase as you move north or south of the equator. This type of map is designed so that distances can be measured directly from the map scale in any direction. A typical 50,000:1 scale topographic map will have a 1 kilometre grid. Instead of degrees, the east-west and north-south lines are measure in metres. Grid coordinates are given in “eastings” and “northings”. Topographic maps and orienteering maps usually use UTM coordinates therefore distances on these maps are easy to calculate. Calculating the distances between two points using the lat-lon system requires using trigonometry and is beyond the scope of this lesson.

CONCLUSION
HOW SHOULD THE CADETS BE TESTED?
The requirement for promotion includes the ability to read a map and to determine any point on the map by grid reference. This can be accomplished easily through individual assessments, or with an in-class practical exercise.
IS THERE ANYTHING ELSE I NEED TO KNOW?