Cartographic Principles Flashcards
What are maps?
Maps are transformations of reality which are totally subjective.
Why is a map drawn?
For a purpose and to communicate.
What is cartography?
You take the real world and all its data and information and putting it onto a Cartographic map.
The process of mapping has two main activities, what are they?
1) Data collection (capturing spatial data, through surveying or remote sensing etc).
2) Data presentation (producing an artefact, that communicates it to the person who is reading the map).
What do you have to consider when developing a map? (2)
1) Availability of data
2) delivery methods.
What is G.I.S based on?
G.I.S. is based on location and on spatial attributes.
How long have maps been presenting data for?
A millennia.
Are we at the peak of map making?
Yes because more data is being collected; more maps are being produced than ever before.
What is the technology today/in future to create maps?(5)
- Sensor developments
- Positioning technology
- Web delivery
- Data integration (e.g. BIM)
- Visualisation
What are the cartographic principles? (5)
- Location, attributes
- Scale, projection, dimensional change
- Points, lines, areas, surfaces, sequences
- Generalisation and symbolisation
- Marginal data.
What real world data can be used on maps?
Location/topology, topology map is how things are connected on a map, quantitative/qualitative/attribute data.
What are global system based on?
Meridians and parallels (the graticule).
What unitS do we use in G.I.S?
Degrees, minutes, seconds or decimal degrees (E-W first, N-S next) OR East and North positive, West and South negative (possibly).
Why is there different coordinate systems?
Due to the irregularities on the earth. Each recognises a different centre to the earth, and different parameters for the ellipsoid.
What is projection?
A transformation of reality (using location data). Geographical coordinate position into a two-dimensional plane “coordinate”.
Complete the phase “the larger the area…..”
The more distortion.
What are the characteristics of a grid system?
1) Rectangular “coordinates”
2) Easing then northing
What are the characteristics of the OS national grid? (3)
1) 6 figures: 438 567 (precise to …m.)
2) 12 figures: 437838 566993 (precise to …. m.)
3) Uniqueness requires preceding two letter code (NZ in this case).
What is scale?
A transformation of reality (using location data). E.g. • E.g. 1:1000=1/1000 (Representative Fraction). NB 1/1000 (large scale) > 1/50,000 (small scale).
What are the scales for MasterMap data?
Nominal scale 1:1250 (urban areas); 1:2500 (rural areas); 1:10000 (mountain areas):
What are the scales for printers and scanners?
1:25000; 1:50000; 1:250000; 1:1 million (printed paper maps, and digital raster scans)
What is generalisation?
A transformation of reality (using location and attribute data).
When are we required to use generalisation?
Required for any representation at reduced scale, simplification.
What do contours represents?
Contours represent relief.
What does symbology do?
Where symbols are transformation of reality (using attribute data).
How can you help the interpretation of a map? (5)
Need to add supplementary information:
1) text in map face
2) Marginal and border information
3) Identification
4) Scale
5) Locational data
What are the 3 main factors we need to consider when making a map?
1) Readability
2) Detail
3) Accuracy
