Lecture 3: Navigation Flashcards
Define Navigation
a set of skills that involve the determination of position, direction and size (length, area)
What are the 3 critical measurements for navigation
➢distances between locations
➢directions between locations
➢area of a location
What is scale?
the ratio between the size of something and a representation of it( fundamental concept of mapping, like space)
What is a map scale?
A scale that shows the ratio between the size of features on the map and the size of the features in the real world
What is a representative fraction?
the ratio between the size of features on the map and features in the real world
What is a large scale map?
shows a greater amount of detail
E.g., Washington DC as a polygon
What is a small scale map?
shows less detail
What are the different ways to express map scales?
- scale bar
- ratio (aka representative fraction)
- written text
How do you check to see which map is larger?
Convert the scale to decimals
What is a unit less scale?
A scale with no units,
1 meter/500 meters = 1 mile/500 miles
The scale is simply 1/500
What is the first way to estimate distance on a hard copy map?
Use a ruler to measure the distance on the map, then use the representative fraction to calculate the ground distance
What is the second way to estimate distance on a hard copy map?
Use your finger to estimate a ground distance using the scale bar
How do you measure distance on a digital map?
Euclidian distance (Distance formula)
What are contour lines?
They show topography or changes in elevation
What do contour lines show specifically?
- the location of slopes, depressions, ridges, cliffs, height of mountains and hills
- connect all points of the same elevation
What is a contour interval?
the difference in elevation between two adjacent contour lines, every fifth line is the index contour is printed darker and has the elevation in feet from mean sea level marked on the line
What is Azimuth?
➢measured in degrees: N = 0o , E = 90o , S = 180o , W = 270o , almost N = 359o
➢useful for navigation between two points over short distances
➢Also called a bearing
What are cardinal directions?
North, South, East, West
How do you find the area of irregular shapes?
for each line segment (in clockwise direction), work out the area down to the x-axis
What is Wayfinding?
general methods people and animals use to orient themselves in space and move from place to place
•more about cognitive maps and mental processes
