29 terms

GIS exam_lsx

Contour Lines
lines that connect points of equal value.
Vector Data Forms
Points, Polygons, Lines
Discrete Variables
Fixed entitites, Can only take a specific value (Ex. number of students in a class, anything that is counted and not measured)
Continuous Variables
can assume all values between any two specific values. They are obtained by measuring.
Most popular form of USGS Map
7.5' Map
map in which some thematic mapping variable is substituted for area (like a graph in a map)
explanatory list of symbols on a map
North Arrow
symbol on a map used to show direction
Parts of Map
title, legend or key, grid system, distance scale, direction and compass rose
The Land Ordinance
townships were six miles square, and were subdivided into 36 sections, each section consisting of one square mile. One section of each township was set aside to support public education, and the remaining sections were to be sold at public auctions.
Verify Query
To avoid corrupt data!
Thematic Maps
A map containing information on only one topic or theme.
Reference Maps
maps that show the absolute location of places and geographic features determined by a frame of reference, typically latitude and longitude
Navigational Maps
sailors and pilots use these maps to navigate
Attribute Table
a tabular file containing rows and columns; descriptive attributes about some object such as a geographic feature are contained in each row
Natural Breaks
classes based on natural groupings through examination of histogram
(good: minimizes differences
bad: data range uneven)
Are points taken at regular intervals from the cumulative distribution function (CDF) of a random variable.
Equal Interval
A data classification method that divides a set of attribute values into groups that contain an equal range of values
Bands: 7
Spatial Res: 30m
Temporal Res: 16 day
Swath Width: 183km
Bands: 36
Spatial Res: 250m
Temporal Res: 1 day
Swath Width: 2,330km
Remote Sensing
The acquisition of data about Earth's surface from a satellite orbiting the planet or other long-distance methods.
Spectral Resolution
The range of wavelengths sampled by a remote sensor.
Swath Width
area of the Earth that is displayed in each image
Spatial Resolution
the smallest pixel size visible in an image, the limit of magnification
Dot Density Map
Thematic map that uses dots to represent the frequency of a variable in a given area.
Conformal Maps
Preserve Shape
Azimuthal Maps
Preserve Direction
Temporal Resolution
precision of a measurement with respect to time
Blue, Green, Red, NIR....