Final Exam Review Geography 170

What is a geographic coordinate system?

A geographic coordinate system uses a three dimensional (3-D) spherical surface and measure of latitude and longitude to define location on earth.

Geoid

Accounts for variations in gravity across earth's surface Is a vertical datum and a hypothetical Earth surface that represents the mean sea level, assuming Earth's surface is completely covered by water

Persuasive Maps

Called Propaganda Maps and usually seen in public medias. Maps intended to convey an idea rather than communicate geographic information. Mapmakers deliberately try to persuade you to choose a particular product or support a certain argument. ex: The United States of Shame: What is your state the worst at? What does your state do well?

Thematic Maps

Depict spatially- referenced variables of interest (attributes). Or information about a particular topic. Ex: weather, population density and geology maps. (stress the geographical distribution of a particular topic)

Reference Maps

Depicts location. (location of geographic features) Reference maps emphasize the location of spatial phenomena. Reference maps have a primary purpose of summarizing the landscape to aid discovery of locations. Therefore, the Geographic features are depicted as detailed and spatially trustful as possible Ex: road maps, google maps, bing map, map quest.com, openstreemap.org, USGS, Topo maps It is colorful - colors have specific meanings. Cities are named. Major transport routes (highways and local road) are identified. Natural features such as rivers, lakes and mountains are named.

Distortion

Distortion always exist

Describe the shape of the Earth

Ellipsoid Datum Geoid

In general , geospatial and nonspatial data cannot be linked in useful ways.

False- can be used through GIS techniques.

All data have geospatial aspect

False- not all data have a geospatial aspect. One example the ISBNs of books on a the shelves in a library do not have geospatial aspect.

What are three major geospatial technologies? GIS RS GPS

Geographic Information System (GIS): a computer-based geospatial technology for storage, analysis, and management of location-based data. Remote Sensing (RS): a technology that is used to acquire imagery of the earth's surface through the use of satellites or aircraft. The data collected by satellite devices are typically called satellite imagery, and data acquired by devices on aircraft are called aerial photos. Global Positioning System (GPS): a technology that acquires real-time location information from a series of satellites in Earth's orbit.

What is geospatial technology?

Geospatial technology describes the use of a number of different high-tech systems and tools to acquire, analyze, manage, store, or visualize various types of location-based data Location-based data, or geospatial data is the core of geospatial technology. Such data include information about or attached with space and location. For example, a bike trail map of a city, house prices in different neighborhoods, and population density distribution are all considered geospatial data.

Navigational Maps (Navigational Charts)

Maps created specifically to help the navigate plan and follow a travel route. Nautical Charts: created specifically for water navigation Aeronautical Charts: designed for air navigation. ex: map that helps a flyer know if location flying over is safe.

Ellipsoid (spheroid)

Model the earth as a smooth surface Larger radius (bulges) at the equator

Datum

Reference system for plotting locations on a map (can represent the shape and size of the earth) Geodetic datum can be defined in specifying: the ellipsoid, the coordinates o base point and the direction north. Can be horizontal or vertical models Horizontal examples: Horizontal datums measure a specific position on the Earth's surface using coordinate systems such as latitude and longitude. North American Datum of 1927 (NAD27) North American Datum of 1983 (NAD83) World Geodetic System 84 (WGS84) Vertical examples: Measure Elevations A vertical datum is technically an arbitrary surface of zero elevation. The vertical datum allows height measurements of various points be in a consistent system. More broadly, a vertical datum is the entire system of the zero-elevation surface as well as methods of determining heights relative to that surface. One of the most commonly used vertical datum is the geoid. The geoid is a hypothetical Earth surface that represents the mean sea level (MSL). The MSL is often determined by averaging the level of water at a tide gauge over time

Which of the following is NOT a form of geospatial data?

The assessed value of a particular house b/c it is attribute data and not spatial data. Spatial Data tells you: Boundaries of housing parcels in a subdivision The distribution of salary in a particular county The exact address of a house in Biloxi, Mississippi

What is geographic information?

The atomic elements of geographic information include location and (x,y), time and other attributes. Time is an optional element in geographic information, (it is a spatially dependent variable) but location is essential Geographic attributes are specific statistics tied to geographic location, e,g., population density, tax rates, health data (lung cancer rate,) temperature, air pressure ect.

Geogrophy

The study of earths surface as the space inhabited by the human population.

How to represent geospatial technology?

Through Maps: Maps can be used to communicate geographic information in a variety of forms. Based on the fusion of the maps, maps can be categorized into different types: Reference Maps Thematic Maps Navigational Maps Persuasive Maps

Geographic Coordinates (Latitude and Longitude)

Unit: Degrees Latitude: 0-90 Longitude:0-180 Length of a degree of longitude decrease from the equator to the pole

What is map projection?

a mathematical process of transforming a particular region of the earth's three-dimensional curved surface onto a two-dimensional map. Map projections allow us to represent some of, or the Earth's entire surface, on a flat easily transportable surface, such as a sheet of paper. You can also change how you express location. (spherical lat+long) In a fatten map by coordinates.

What is google earth?

3D virtual globe It maps the Earth by the superimposition of images obtained from satellite imagery, aerial photography and geographic information system (GIS) onto a 3D globe. (Think of a globe you've used in high school geography class.)

Geographic Information Systems m (GIS)

(GIS-analyzes and manages data) Computer-based mapping, analysis, and revival of location-based data.

Global Positioning System (GPS)

(GPS and RS Collect Data) a technology that acquires real-time location information from a series of satellites in Earth's orbit.

Remote Sensing (RS)

(GPS and RS collect data) a technology that is used to acquire imagery of the earth's surface through the use of satellites or aircraft. The data collected by satellite devices are typically called satellite imagery, and data acquired by devices on aircraft are called aerial photos.