difference between a map and a figure?	coordinates indicating geographical location on the surface of he Earth	x and y
geospatial info stored in databases is __ % of all information	>80
limitation of paper based maps (3)	Info coded as symbols and colors (qualitative information), large areas = several map sheets, combination and sharing of info is difficult	qualitative, scale, static
Adventages of computer cartography (8)	Quicklier(!) no skilled staff needed (!) cheaper allows experimentation in representation with the same data facilitate updating facilitate analysis of quantitative data generalization on quality of data easier to make (3D maps)	statistical analysis and mapping cost, experience, updating, quality defined, better analysis (3D) and experimentation
Reference maps	several types of info summarizes often covers large areas deals with geography of a region (understanding)	maps in atlases
Thematic maps	detailed information about a topic of particular interest tailored to particular user needs	road map, risk map
GIS IS...	integration of digital geographical information computer technology GIS science (knowledge about integration)	3 things
GIS history	pioneering (1957) commercialization (1980) user proliferation (2000) open source (2010) at first restricted (military, government & private companies) recently open to general public	application, technology and commercial details. academic and general as well
GIS toolbox definition	A geographic information system is a computer-based information system that enlables: collecting, storing, retrieving, modelling (analysis), and representation of geographically referenced information"	C - S - R - M (A) - R
components of GIS (6)	network hardware software data procedures people	N -> (H, S, D, Procedures and People)
GIS chain	expertise structured data organization hardware/software	updating: data, software, knowledge
Application of GIS	government and public services (tracking crime, land use planning, environmental monitoring, geodemographics) business & service planning (where costumers are, geodem) logistics and transportation (gps) environment
GIS is the combination of	computer cartography (CC) database management (DBM) remote sensing (RS) computer-aided design (CAD)	display and printing storing and retrieving data information extraction (raster) input, assumed for design (vector)
Land Information System (LIS)	GIS with focus on the analysis of _natural land resources_ (soil, water, geology, landscapes, topography, land use, vegetation, climate...) with applications in agriculture, land planning, management of natural ecosystems, environmental management, etc.	natural land resources (8 examples) applications in (4 examples)
REAL WORLD TO GIS	RW - conceptual model - logical model - physical model - limitations	binary information; tons of information (symbols, proximity, extent)
data modelling	interpreting reality by using a conceptual and logical model	RW complex (need to simplify)
conceptual model	human-oriented model of selected entities (basic carriers of information) and processes that are thought relevant to a particular problem	real world model (relevant entities and processes)
logical model	oriented representation of reality entities comprise different objects (physical -roads-, classified -soil types-, events (waterleaks), artificial - elevation contours)	(data model)
objects description	-identity (identifier -numbers-) -geometric and attribute data (point/line/area and nominal, interval ratio) -spatial relationships (intersects etc and proximity) -quality (roads)
physical model	describes the exact files or database table used to store data, the relation between objects and the precise operations that can be performed
building a conceptual model of reality	asking what your final product needs to be break down or decomposed to final product into the general types of maps that you need to use determine which aspects of each map do you need to examine (defines the map elements (features and their data) that ultimately plan to combine to create your file map	model creation process
summary	-real world (general view -landscape-) -conceptual model (unique entities -houses-) -data model (entities with attributes -table with basic characteristics) -data base (digital data coding (geography and attributes) -real table-) -map	RW-CM-DM-DB-MAP
uncertainty	generalizations make possible to obtain an overview of our complex reality	generalizations need choices
DIGITAL SPATIAL INFORMATION	the geographical database basic map concepts data structures
digitizing a map (2)	digitizing scanning	raster or vector based
geographical database	the real world consists of many features, which can be represented as a number of relates single theme data layers with each layer linked to a common georeferencing system	layers represent real world
graphical representation of spatial objects	node (arc), vertex (polygon) vector arc polygon raster (cells) pixels	vector based mapping raster based mapping
Traditional paper maps	set of points lines areas defined by -location -legend (attribute information using colours and symbols) -topology (spatial interrelationships)	3 characteristics
definition of vector	a straight line segment whose length is MAGNITUDE and whose orientation in space is DIRECTION	magnitude and direction
point, arc, polygon are vectors...	with zero length, combinated and connected c,c and closed	N for node a for arc P for polygon
spaghetti data models vs arc node days models	topology	endpoint nodes, shared nodes,
usefulness of topology	automatic calculations verification of data consistency analysis
object oriented data model	combine the characteristics of objects and slept relationships with other objects (states + behavior)	more modern than the other two (examples: intersection roads with highways or polygons must not overlap)
definition of raster	"a matrix", a regular grid of squared cells of equal dimensions -location of each cell determined by idt row & column number -value assigned to the cells represents code of the attribute	-identifier -qualitative or -quantitative attribute value
resolution	linked to accuracy and data storing capacity the finer the resolution, the more detail an increase of 2x in resolution is a 4x increase in number of pixels
vector vs raster	vector (compact, efficient data structure, only boundaries are stored, updating and querying is very efficient and quick) - aesthetically nicer	vector adventages
Raster vs Vector	-overlay more efficient -more analitical power when mathematical operations -required when remote sensing information -spatially continuously varying phenomena (topography, climate, soil, water,air)
Summary of adventages and disadvantages (Raster)	(A) - Simple data structure, overlay operations easy and efficient, representation of spatial variability, required when working with images (for efficient enhancement and manipulation) (D) - less compact, topological relationships difficult to represent, output less aesthetically pleasing (due to boundaries with blocky appearance or unacceptable large files)	squared, overlay, variations, pictures less compact, topology relations difficult, less aesthetical
Summary of adv and disadv (Vector)	(A) - compact structure, efficient encoding of topology -> easier network analysis, better in representation (output) (D) -complex data structure, more difficult to overlay, high spatial variability representation is inefficient, manipulation and enhancement of digital images not effectively done	compact data structure, clear topology, nice representation complex data structure, difficult overlays, HSV inefficient, images
application fields of vector and raster	network topology (industry) large databases (governmental bodies) mapping (commercial applications) analitical power and east concept (research and teaching institutions)	most modern GIS are hybrid systems
MAP SCALE AND PROJECTIONS	scale datum ellipsoid projections (distortions)
Projection formulas	mathematical expressions that convert data from a geographical location on a spheroid to a representative location on flat surface
4 types of distortion	shape areas distances directions
Map scale (large or small)	more detailed -> large scale less detailed -> small scale 1/10000 > 1/1000000	Detail
map projections (Earth to map)	mathematical conversion between the Earth ellipsoid and a flat paper -angles measured from the Earth's center point (graticule network), rather than distances on the surface -distance represented by 1° longitude will reduce towards the poles	°
types of projections	shape (plane, cylinder, cone) points or lines of contact (cut or touch, no distortion there) orientation (transversal, equatorial) depending on the chosen projection, we can preserve (shape, area, distance along lines, distorts all, but balances)	3 all can roach
coordinate Systems (3)	geographic coordinates (°, origin, length of 1° longitude varies with the latitude, not planar, accuracy of 0.001°) UTM (m, 60 different projections of 6° width -1st is from 180 to 174°W, subdivision 60S or 60N, local planar systems	universal transverse Mercator

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