Module 3 Notes

Talking about maps and measurements and all that

Verbal Scale

Easiest scale to understand; uses familiar units to describe the scale

Bar Scale

Important when enlarging or reducing maps by photocopy; uses a bar graphic to show the scale

Representative fraction

1.) 1:24000

2.) uses a proportion or ratio to show scale

3.) Universal for any language and unit

Data precision

The smallest difference between adjacent positions that can be recorded and stored

Data resolution

the degree to which closely related entities can be discriminated

Raster Data

1.) stored as usually square pixels

2.) form a grid or mesh over an area of the Earth

Data density

a measure of how many features per area are stored, and may imply a minimum feature size

Data detail

A measure of how much information is stored for each feature