|
18 | 18 | "The earliest examples of raster data are aerial photographs taken on board of aircraft that are transformed into digital format. The photograph would become a matrix of geo-referenced values - the raster. \n", |
19 | 19 | "\n", |
20 | 20 | "\n", |
| 21 | + "\n", |
21 | 22 | "*Image from [Wikipedia](https://en.wikipedia.org/wiki/Aerial_photography#/media/File:Cecil_Shadbolt_collection_-_54_-_An_aerial_view_showing_Stonebridge_Road,_Stamford_Hill,_and_Seven_Sisters_Curve,_part_of_the_Tottenham_and_Hampstead_Junction_Railway,_taken_from_2000ft.jpg)*\n", |
22 | 23 | "\n", |
23 | 24 | "\n", |
| 25 | + "\n", |
24 | 26 | "*Satellite image from [Sentinel Hub](https://www.sentinel-hub.com/blog/building-added-value-services-top-sentinel-hub)*\n", |
25 | 27 | "\n", |
26 | 28 | "\n", |
| 29 | + "\n", |
27 | 30 | "*Digital Elevation Model from [GISGeography.com](https://gisgeography.com/free-global-dem-data-sources/)*\n", |
28 | 31 | "\n", |
29 | 32 | "A raster captures a continuous phenomenon into a ***regular [tessellation](https://en.wikipedia.org/wiki/Tessellation)*** of space. Within each tile or cell of the raster the value of the phenomenon or variable of concern is constant. The location and size of each cell is perfectly known since the tessellation is regular. This process of collecting a continuous variable into a raster is sometimes referred to as ***discretisation***.\n", |
30 | 33 | "\n", |
31 | 34 | "\n", |
| 35 | + "\n", |
32 | 36 | "*A matrix of values composing a raster from [StackOverflow](http://stackoverflow.com/questions/26705092/plot-a-matrix-values-as-colors)*\n", |
33 | 37 | "\n", |
34 | 38 | "As many satellites carry various sensors on board, often raster files represent more than one phenomenon or variable. In essence, it is composed by more than one overlapping matrices. These individual matrices are known as ***bands***.\n", |
35 | 39 | "\n", |
36 | 40 | "\n", |
37 | 41 | "\n", |
| 42 | + "\n", |
38 | 43 | "*Three visible bands from a satellite can be combined into a colour image. Source: [Neon Science](https://www.neonscience.org/dc-multiband-rasters-r)*" |
39 | 44 | ] |
40 | 45 | }, |
|
523 | 528 | "name": "python", |
524 | 529 | "nbconvert_exporter": "python", |
525 | 530 | "pygments_lexer": "ipython3", |
526 | | - "version": "3.10.6" |
| 531 | + "version": "3.12.3" |
527 | 532 | } |
528 | 533 | }, |
529 | 534 | "nbformat": 4, |
530 | | - "nbformat_minor": 2 |
| 535 | + "nbformat_minor": 4 |
531 | 536 | } |
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