GIS Flashcards
What does GIS stand for?
Geographic Information Systems
What is hardware?
CPU, screen, keyboard, mouse etc.
What are the components of GIS?
Hardware, software, data, methods, and people
Concept of remote sensing? 💚
The process of capturing data using modern technology to obtain spatial information about the earth’s surface where there is no physical contact between sensor and object.
For example, the use of satellites and the viewing of the earth’s surface from an aircraft (as an aerial photo).
What is a low oblique aerial photograph?
Only ground surface visible. Camera axis about 30° from vertical.
What is a high oblique aerial photograph?
Surface features and her Rison visible. Camera axis about 60° from vertical.
Note
Page 13 in mapwork booklet:
Read about vertical aerial photographs, orthophotos and satellite images. Know descriptions, advantages and disadvantages.
(I can’t find it in the department notes)
What is the difference between high resolution and low resolution?
High resolution: many pixels. small pixels. Objects easily recognised
Low resolution: Fewer pixels. Large pixels. Objects not easily recognised.
💚Concept of raster data?
Objects on the surface of the Earth are represented by rows and columns of evenly sized blocks, called pixels. Pixels are the smallest unit of data storage.
💚Concept of vector data?
Objects on the surface of the Earth are represented by using points, nodes, lines or areas (polygons).
What are the 2 types of resolution?
Spectral resolution
Spatial resolution
What is spectral resolution? (Not in guidelines)
The ability of the sensor to detect information over several spectral bands (red, green, and blue, infrared, ultraviolet, etc.)
Concept of spatial resolution?
Refers to the quantity of detail that can be detected.
What is buffering?
A zone drawn around a mapped feature measured in units of distance or time.
How can G I S be used in agriculture, crime prevention, traffic congestion, financial, mining and personal use?
Agriculture: rainfall patterns, predicting climate, soil type, suitability of crop
Crime prevention: crime statistics in spatial patterns
Traffic congestion: controlling traffic lights based on information collected
Financial: fines monitoring customer patterns of behaviour
Mining: exploring for mineral deposits
Personal use: finding out the shortest route to school. Find a house which is the safest place etc.
Concept of spatial data? 💚
Data that shows location, which is mainly in the form of a map. The specific location can be geo-referenced according to longitude and latitude.
Concept of attribute data?💚
Data set information describing geographical characteristics of features or information that can be linked to spatial data.
What are the two types of layers?💚
Static (same colour, distance etc.)
Thematic (different colours to differentiate areas, rivers shown with thicker lines than actual width, etc.)
What is a buffer zone?
An area between 2 zones that either segregates them or conjoins them
What is layering?
Maps showing different types of information are placed on top of one another.
What are the 2 types of raster data?
Discrete (has a fixed shape/ end point, e.g. population density(?), lake, building)
Continuous (gradual change in degree, e.g. temperature and elevation)
Creating zones of pre-determined width around a point, line or polygon
Buffering
Know how to do buffering for a line, point or polygon.
Look in the Geography Mapwork notes Gr.10-12
🌺
Data manipulation 💚
The process used to organise data for your specific needs. Changes that one makes to the data during analysis. It involves converting, rearranging and analysing data to get answers.
Concept of resolution 💚
Amount of detail with which a map depicts the location and shape of geographical features. The larger the map scale, the higher the possible spatial resolution. The area shown is smaller; hence more detail will be shown.
What does GPS stand for? 💚
Global Position Systems
Data standardisation
Process of transforming data onto a common scale of measurement in order to ensure comparability
Data sharing
The practice of making data used for research available to other users to prevent duplication
Data security
Keeping data from being accessed by unauthorised users and from being corrupted
Statistical analysis (not def.)
A wide range of mathematical techniques and methods used to describe, explore, understand, prove and predict overall trends from large data sets
The combination of two or more data layers in order to create a new layer that can be used for further integration, manipulation and analyses
Data integration
How can GIS be applied by the government?
Management of water resources and wetlands
Land information can be used for taxation
Land information can be used for land-use zoning
Detecting urban heat islands using an infrared band at night with clear skies
Electricity network and water works
How can GIS be applied by the private sector?
Farmers optimise fertiliser placement
Retail companies find locations for new sites
Transport fleet managers can track truck locations
Meteorologists can forecast weather
What are the 4 types of scale? (p.10)
Word scale
Representative fraction
Ratio scale
Line scale (or linear/ graphic scale)
Name two types of photographs
Vertical aerial photographs
Orthophoto maps
Give 2 advantages of vertical aerial photographs
Show objects as they appear in reality
Easier to read than maps
Show a vast amount of detail
Enable us to see object changes over time
Give 2 advantages of orthophoto maps
Has been rectified (is true to scale)
Large scale - easier to identify features
Includes scale, names of places and features, contour lines, spot heights etc.
Concept of GIS 💚
A system of hardware, data, people, organisations and institutional arrangements for storing, analysing and disseminating spatially-linked information.
Querying 💚 (not def.)
Asking a GIS database a question
Any organised assembly of resources and procedures united and regulated by interaction or interdependence to complete a set of specific functions
System
A system, whether automated or manual, that comprises of people, machines and/or methods organised to collect, process, transmit and disseminate data that represent user information.
Information system
A collection of information about spatial locations and shapes of geographical features recorded, stored and organised in such a way that a computer program can quickly select desired pieces of data.
Geographical database
A database can be thought of as an electronic filing system.
The process of linking phenomena such as points, lines and areas to their location on the earth’s surface. It involves converting a place to X and Y coordinates so that it can be accurately plotted on a map.
Geo referencing
Concept of points
Zero-dimensional representations of features with locations and attributes
Concept of lines
One-dimensional representations of features with a start and end point
Concept of nodes
Points that are found at the start and end of a line or where two or more lines meet, in which case they represent junctions or intersections
Points found along a line
Vertices
Concept of polygons
Two-dimensional representations of features made up of a series of lines where the starting point is the same as the ending point
A process of identifying and collecting specific information to solve a particular problem
Data acquisition
An area represented by each cell or grid in a raster. The detail of the raster data depends on the size of the grid cells.
Pixel resolution (high if there’s lots of detail).
The ability of a sensing system such as a satellite to differentiate between electromagnetic radiation of different wavelengths. It also refers to the range of wavelengths seen by a particular sensor.
Spectral resolution
The process of correcting errors in the data and removing irrelevant information
Pre-processing
The degree to which spatial information which has been captured satisfies the stated needs
Data quality
The process of extracting or creating new information about a set of geographic features and examining the relationships between them.
The process by which we turn raw data into useful information.
Spatial analysis
Pixels
Pixels are the smallest unit of data storage.
Layering of information
Maps showing different types of information are projected onto one another
Systematic and logical organisation of data so that it is usable. Data is stored in folders and files on a computer. It’s makes it possible to protect data, allows for data sharing and for the maintenance of data quality as well as having a backup system
Data-management
