GIS and Remote Sensing Flashcards
It combines location and info about the location, can overlay different spatial info at once
Geographic Information System (GIS)
Info associated with an underlying geography, or description of location
Spatial Information
The science that deals with the construction, use, and princiles behind maps and map use
Cartography
Imaginary lines that runs horizontally, degrees latitude are numbered 0 to 90 north and south.
= aka as parallels
Latitude
The imaginary line that divides the north and south hemisphere
Equator
Latitued and longitude are ______ apart from each other
69 miles or 111 km
Imaginary lines that runs vertically and also known as meridians
Longitudes
0 degree longitude refers to __________ and is located at Greenwhich, England and continues 180 degrees east and west where they meet and form the __________ in the pacific ocean
Prime meridian and International Date Line
The key to read a map, and provides the essential info for the map reader
Map Legend
Ratio between distance on a paper map and distance of the same stretch in actual terrain
Map scale
- The accuracy with which a given map scale can be depict the location and shape of map features
- the smaller the map scale the higher the possible resolution
Resolution
The minimum size of objects that can be detected by a sensor system
Spatial Resolution
- used to portray all or part of the round earth (3D) on a flat surface (2D) map
Projection
A map parts of a map can show one or more, but never all of the following:
- true directions
- true distances
- true areas
- true shapes
Remember
- Longitudes equally spaced
- Latitudes unequally spaced
- scale is true along the equator
- shape and scale distortions increase near poles
- shows true directions
- universal traverse mercator (UTM)
Cylindrical Projection
- Result from projecting a spherical surface onto a cone
- best for mid-latitudes with an east-west orientation like canada
Cone projection
- result from projecting a spherical surface onto a plane
- best for polar or circular regions
- directions always true from center
Azimuthal (planar) projection
- It enables systems geographic datasets to use common locations for integration
- reference system used to represent the locations of geographic features, imagery, and observations such as GPS loc with common geographic framework
Coordinate system
A combination of factors; ellipsoid, geoid, datum, coordinate system and projection that identify a point on a sphere and on a two dimensional representation of the sphere
Spatial Reference Framework
The science of measuring the earth
Geodesy
The science of identifying and measuring specific loc on the earth
Surveying
A mathematical model of the size and shape of earth
Ellipsoid
Slightly non-spherical object, but not necessarily mathematically definable
Spheroid
A theoretical surface generated defined as mean sea level. Used as the basis for a veryical datum and as a reference for a horizontal datum
Geoid
A spheroid used as an (X,Y) reference to all points the real globe
Horizontal Datum
Level surface to which heights (elevation) are referenced
Vertical Datum
2 types of coordinate sytem
- Global or Spherical Coordinate System
2. Projected coordinate system
_____________ such as latitude-longitude. These are often referred to as geographic coordinate system
Globa or spherical coordinate system