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