Text Flashcards

1
Q

geospatial technology

A

a number of different hightech systems that aquire, analyze, manage, store, or visualize various types of location-based data
-anything using information with location associated with it

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2
Q

GIS

A

Geographic information system
.computer based set of hardware and software used to capture analyze, manipulate, and visualize geospatial information
-computer based mapping, analysis, and retrieval of location based data
. Term GIS first appeared in 1960s with the implementation of CGIS(Canadian Geographic Information System), which was designed to provide large scale mapping of land use in Canada

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3
Q

Remote sensing

A

axquisition of data and imagery from the use of aircraft and satellites

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4
Q

sattelite imagery

A

digital images of earth acquired by sensors onboard orbiting spaceborne platforms

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5
Q

aeriel photography

A

acquisition of imagery of the ground taken from an airbourne platform

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6
Q

Global positioning system

A

GPS

-acquisition of real time location information from a series of sattelites in earths orbit

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7
Q

GEOINT

A

Geospatial intelligence

-geospatial technology used for military

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8
Q

Geospatial data(spatial data)

A

items that are tied to specific real world locations
-location based data
-

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9
Q

non-spatial data

A

data that is not directly linked to a geospatial location (such as tabular data)
-names of occupants, value of a house, value of land

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10
Q

The National Map (US)

A

an online basemap and data viewer with downloadable geospatial data maintained and operated by the USGS and part of the national geospatial program

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11
Q

GISci

A

Geospatial information science or Geospatial technologies

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12
Q

crowdsourcing (citizen science)

A

the activities of untrained volunteers too create content and resources that can be utilized by others

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13
Q

geolocation

A

the technique of determining where something is in the real world

  • use of IP address of device
  • wifi connection
  • cell towers your phone is connected to
  • gps reciever
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14
Q

W3C Geolocation API

A

the commands and techniques used in programming to obtain the geolocation of a computer or mobile device

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15
Q

geotag

A

connecting real-world location information to an item

-ex: picture, photo

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16
Q

virtual globe

A

a software program that provides an interactive three dimensional map of earth

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17
Q

datum

A

a reference surface or model of Earth that is used for plotting locations anywhere on the actual surface of the earth
-representes the size and shape of earth, which contrary to popular belief is perfectly round
-earth actually ellipsoid or spheroid (larger at center then poles)
-mathematical model against which to reference locations and coordinates
100s of datums in the world
-some measure whole world and others just regions or countries
-measurments from one dont always match with another

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18
Q

Earth is actually ____ or _____ not a perfect sphere

A

ellipsoid, spheriod

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19
Q

geoid

A

a model of earth using mean sea level as a base

-tries to account for differences in earths shape which is augmented by gravities pull

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20
Q

Geodesy

A

the science of measuring Earths shape

-to develop models and reference surfaces

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21
Q

NAD27

A

The North American Datum of 1927
. this datum was developed for measurments of the United States and North America. It has its center point positioned at meades ranch in Kansas

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22
Q

NAD83

A

The North American Datum of 1983
. This datum was developed by the National Geodetic survey, together with Canadian agencies, and is used as the datum for much data for the US and the N.A continent as a whole
. NAD83 is very commonly used, the US national geodetic survey is currently preparing a new datum to take its place, but it wont be ready until 2022

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23
Q

WGS84

A

The World Geodetic System 1984
. This datum was developed by the US department of defense and is used by the Global Positioning System for locating points worldwide on Earths surface

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24
Q

datum transformation

A

is required to alter the measurments from one datum to another
. is a computational process, a standard one in many geospatial software packages
. Datums can be used to set up geographic coordinate systems (GCS) for measuring coordinates

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25
Q

Geographic Coordinate System

A

GCS
.a global reference system for determining the exact position of a point on earth
. a set of global lat and long measurments used as a reference system for finding locations
.GCS measurments are in degrees minutes and seconds

26
Q

Latitude

A
imaginary lines on a globe north and south of the equator that serve as a basis of measurement in GCS
.aslo referred to as paralells
. run east to west direction
.equator serves as point zero
- 0 to 90
27
Q

Longitude

A

. run north to south
. Prime meridian serves as starting point of zero
. imaginary lines on the globe east and west of the prime meridian, they serve as basis of measurment in GCS
- 0 to 180

28
Q
degree= \_\_ minutes
second= \_\_ seconds
A

60,60

29
Q

1 single minute of lat is equal to about __ nautical mile

distance between degrees of longitude varies at different places on earth, lines of long get closer together as hey approach the ____ and are farthest appart at the _____

A

1

poles, equator

30
Q

lines of latitude are measured in angular units from the ______ while lines of longitude are measures in angular units from the ______

A

Equator

Prime Meridian

31
Q

Prime Meridian

A

the line of longitude that runs through greenwhich england and serves as the 0 degree line of longitude from which to base measurments

32
Q

decimal degrees

A

. the fractional decimal equivalent to coordinates found using degrees, minutes, and seconds

33
Q

__ degrees of longitude per hour

A

15

15 x 24= 360

34
Q

International Date Line

A

marks the devision between 24hour periods and divides one day from another, but it also bends to accomodate considerations of geography, political boundaries, and conveniance, and makes detours to include islands in one time zone or another rather then strictly following the line of the 180th meridian

35
Q

map projection

A

the translation of locations on the three dimensional earth to the 2 dimensional surface

36
Q

4 types of map projection distortions

A

direction, shape, size, distance

37
Q

Mercator Projection

A

. developed in 1569 by Gerardus Mercator
.for use in navigation aid
-designed so every straight line on the map was a line of constant directio
-shapes are kept intact
-sizes are very distorted and become more distorted as you move further form the equator

38
Q

Three main developable surfaces that are used in map projection are:

A
cylinder
-which creates a cylindrical projection
cone
-which creates a conical projection
Flat plane
-creates an azimuthal surface
39
Q

Point of _______, where the Earth touches the surface

A

tangency

-where map distortion is at its least

40
Q

Lambert Conformal Conic

A

. conic projection
.cone intersects earth at two paralells
-commonly used for geospatial data about the US and other East-west trending areas

41
Q

Transverse Merctor

A

. cylindrical projection
. tangency pooint being the intersection between the cylinder and earth
.tangency points are the poles as it wraps around the poles and not the equator
-used for more North-south trending areas

42
Q

UTM

A

Universal Transverse Mercator
. the grid system of locating coordinates accross the globe
.devides the world into a series of zones, and then determining X and Y coordinates for a location in that zone
.set up by trnaslating real-world locations to where they coresponding places would be on a two dimensional surface (using transverse mercator projection)
. only covers Earth from between 84 degrees N latitude and 80 degrees S lat
-CANT BE USED FOR MAPPING POLAR REGIONS
.Universal Polar Stereographic Grid System is used for polar regions
.UTM uses meters rather then degrees minutes and seconds

.display UTM coordinates East/west, North/south, and then the zone

43
Q

T OR F

UTM cant be used for polar regions?

A

T

Universal Polar Stereographic Grid System is used for polar regions

44
Q

UTM zone

A

.globe devided into 60 UTM zones each one 6 degrees of longitude wide and set up as its own cylindrical projection
. Zones 1-60 begin at the 180th meridian and move east

ex: Mount rushmore is zone 13
beijing is zone 56

45
Q

easting

northing

A

. UTM uses meters rather then degrees minutes and seconds
. UTM’s X and Y coordinates are referred to as:

a measurment of so many units east(or west) of some principal meridian

  • measure from central meridian in the zone’s center which is given a value of 500,000 meters, measurments are made to the east(adding meters) or west(subtracting meters) from this value
  • no zone is more then 1,000,000 meters wide so no negative values
  • based on false easting (imaginary central line)

northing is found by counting the number of meters the point is north of the equator
-for instance mount rushmore is located 4,859,580 meters to the north of the equator
-if in the south, dont use negative northings, take the number of meters south and add 10,000,000 to the total
= -3,747,732+10,000,000= 6,252,268
. the 10,000,000 is kknown as the false equator which you can measure from

46
Q

false northing

A

a measurment made north(or south) of an imaginary line such as is used in measuring UTM northings in the southern hemisphere

47
Q

false easting

A

500,000 meters central line in a zone

-measurments made east or west of this imaginary line

48
Q

United States National Grid

A

uses more complicated UTM to pinpoint more accurately a location
-used by feds in US

49
Q

SPCS

A

State Plane Coordinate System
. another grid based system for measuring and determining coordinates
.Used in US for data, especially city and countt data and measurments
.SPCS data was originally measured using the NAD27 datum, but now there are datasets using the NAD83 datum.
. requires a specified zone, easting, and northing in addition to the state in which the measurments are being made
.SPCS zones are formed by following state or county boundaries
-each state often has multiple zones
.identify state, then zone
.each zone has pretermined baseline and principle meridian

. two types exist, one using the transverse mercator for north-south states and one using lamberts conical version for east-west states

.listed as: false easting, false northing, state, and zone

50
Q

CGIS, GIS, was originally developed by Canadian ____ _______; the father of GIS

A

Roger Tomlinson

51
Q

In GIS there are two ways of viewing the world

A

Discrete Object view:
. the world is made up of a series of objects, each of which has a fixed location, or a fixed starting and stopping point, or some sort of fixed boundary
.represented by one of three objects:

points-zero dimensional objects, simple coordinates

lines-these are one dimensional objects, created from connecting starting and ending points (and any points in between that give the lines its shape)

polygons-these are two dimensional objects that form an area from a set of lines (or having an area defined by a line forming a boundary)

52
Q

GIS vector objects

A

.are used to model real-world phenomena using a vector data model

points-zero dimensional objects, simple coordinates

lines-these are one dimensional objects, created from connecting starting and ending points (and any points in between that give the lines its shape)

polygons-these are two dimensional objects that form an area from a set of lines (or having an area defined by a line forming a boundary)

53
Q

vector ____ make up the basis of the GIS vector ____ ______

A

objects

data model

54
Q

GIS vector data model

A

is a means of representing and handling real world spatial information as a series of vector objects-items are realized in the GIS as points, lines, and polygons

55
Q

Digitizing

A

is a common way to create points, lines, and polygons of vector data
-in essence you are tracing or sketching over the top of areas on the map or other image to model features in that map or image in the GIS

heads up digitizing- a map or other image(usually ariel photography or sattelite image) is displayed on the screen as a backdrop

on-screen digitizing-

56
Q

topology

A

the notion of the GIS being able to understand how objects connect to one another independent of their coordinates
-eastblishes adjacency(how one polygon relates to another polygon, in that they share a common boundary, connectivity(how lines can intersect with one another, and containment (how locations are situated inside of a polygon boundary)

57
Q

discrete object view

A

a conceptualization of the world in which all reality can be represented by a series of seperate objects

58
Q

continuous field view

A

a conceptualization of the world in which all items vary accross Earths surface as constant fields and values are available at all locations along the field

  • not everything has a fixed boundary or is an object
    ex: temperature, atmospheric pressure, and elevation
59
Q

Raster data model

A

data is represented using a set of evenly distributed grid cells, with each square cell representing the same area on the earths surface
-when continuous fields are represented and the three vector objects are not affective
.each grid cell must be the same size
.each grid cell contains one single value
ex: National Land Cover Database

60
Q

grid cell in raster data model

A

a square unit representing some real-world size which contains a single value