GEOG 400, Advanced GIS, Fall 2020; Week 5 Lecture 2

Transcript

1. GEOG 400: Advanced GIS - Raster Week 5 – Lecture 2 Focal Raster Operations
2. GEOG 400: Advanced GIS - Raster 1. Local Operations 4. Global Operations 2. Focal Operations 3. Zonal Operations There are four types of raster operations we’ll discuss this week and next: Operations that work on single cell locations one at a time Operations that work on cells within a neighborhood Operations that work on cells within particular zones Operations that work on all cells within the raster
3. GEOG 400: Advanced GIS - Raster 1. Local Operations 4. Global Operations 2. Focal Operations 3. Zonal Operations There are four types of raster operations we’ll discuss this week and next: Operations that work on single cell locations one at a time Operations that work on cells within a neighborhood Operations that work on cells within particular zones Operations that work on all cells within the raster at the same time
4. 1. Local analyses A spatial/mathematical operation is performed on every single cell, individually, independent of surrounding cells 81 59 2 65 35 50 53 73 82 23 97 47 48 72 39 38 input raster operation [divide by 2] output raster 40.5 29.5 1 32.5 17.5 25 26.5 36.5 41 11.5 48.5 23.5 24 36 19.5 19 There are four types of raster operations we’ll discuss this week and next:
5. Slide #5 81 59 2 65 35 50 53 73 82 23 97 47 48 72 39 38 input raster operation [mean] output raster 53.6 neighborhood 2. Focal analyses A spatial/mathematical operation is performed on every single cell, individually, based on some pre-defined neighborhood There are four types of raster operations we’ll discuss this week and next:
6. Focal Operations in ArcGIS • Focal analysis • Focal analyses are one of the unique strengths of raster data • It’s not that you can’t do focal analysis using vector data, but because of the gridded structure of raster data and the resultant inherent topology of raster data, focal analyses are computationally simple in a raster environment
7. Focal Operations in ArcGIS • Focal analysis • Focal analyses are one of the unique strengths of raster data • It’s not that you can’t do focal analysis using vector data, but because of the gridded structure of raster data and the resultant inherent topology of raster data, focal analyses are computationally simple in a raster environment vector focal analysis example
8. Focal Operations in ArcGIS • Focal analysis • Focal analyses are one of the unique strengths of raster data • It’s not that you can’t do focal analysis using vector data, but because of the gridded structure of raster data and the resultant inherent topology of raster data, focal analyses are computationally simple in a raster environment vector focal analysis example raster focal analysis example
9. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Slide #9 Focal Operations in ArcGIS
10. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Focal Operations in ArcGIS
11. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Focal Operations in ArcGIS
12. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Focal Operations in ArcGIS
13. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Focal Operations in ArcGIS
14. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. fire spread modeling • Each temporal step, neighboring cells are evaluated for spread potential (wind, fuel, topography, etc.) and fire is grown accordingly • Focal analysis Focal Operations in ArcGIS
15. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
16. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
17. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
18. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
19. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
20. • Focal analysis • Focal analyses are some of the most important types of analysis for dynamic modeling • e.g. hydrologic flow modeling • Each temporal step, neighboring cells are evaluated for flow direction (based on slope) • Focal analysis Focal Operations in ArcGIS
21. Focal Operations in ArcGIS • Focal analysis tools • In ArcGIS, like nearly all raster analysis tools, the focal analysis tools can be found in the Spatial Analyst Tools • Specifically, in the Neighborhood toolbox • Let’s take a look at how some of them work…
22. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • This is the most flexible and powerful tool in the Neighborhood toolbox Slide #22
23. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Two most important parameters: Neighborhood and Statistics type
24. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Two most important parameters: Neighborhood and Statistics type Slide #24
25. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Rectangle • The simplest neighborhood, particularly since raster cells are square! • Fits a rectangle of height h and width w around the center processing cell • Can be a distance measurement or a number of cells • If distance measurement, neighborhood defined by cell centers that fall within rectangle • e.g. majority land cover in 5x5 pixel area Slide #25 processing cell cells included for processing target neighborhood cells excluded for processing
26. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Circle • Fits a circle of radius r around the processing cell • However, raster cells are square! • All cells that have cell center in circle are included in neighborhood • Like a buffer • e.g. mean PM2.5 air pollution within 100 m of my house Slide #26 processing cell cells included for processing target neighborhood cells excluded for processing
27. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Annulus • Just like the circle (or radius r), except excludes internal area (of radius s) • Like a donut (or a multi-ring buffer) • e.g. terrain analysis – is a cell above (peak) or below (sink) surrounding cells? Slide #27 processing cell cells included for processing target neighborhood cells excluded for processing
28. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Wedge • A unique (and fairly unusual?) case, where you define a wedge neighborhood by a start angle a, and end angle e, and a radius r • e.g. if a fire is burning NW of me within 1 mile, and winds are coming from the NW, evacuate Slide #28 processing cell cells included for processing target neighborhood cells excluded for processing
29. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Irregular • Any neighborhood shape you want! • Defined by a text kernel file Slide #29 processing cell cells included for processing target neighborhood cells excluded for processing kernel dimensions kernel
30. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Weight • Whereas other neighborhoods/kernels are just defining the included cells, weight allows you to dictate influence of specific cells within neighborhood Slide #30 processing cell cells included for processing target neighborhood cells excluded for processing
31. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Remember that with any of these neighborhoods, you need to be aware of how edges are handled • Inclusive • Retain edge cells, but lose filter accuracy • Exclusive • Lose edge cells, maintain filter accuracy Slide #31 processing cell cells included for processing target neighborhood cells excluded for processing ignore_nodata = DATA
32. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Neighborhood • Remember that with any of these neighborhoods, you need to be aware of how edges are handled • Inclusive • Retain edge cells, but lose filter accuracy • Exclusive • Lose edge cells, maintain filter accuracy Slide #32 processing cell cells included for processing target neighborhood cells excluded for processing ignore_nodata = NODATA
33. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Two most important parameters: Neighborhood and Statistics type Slide #33
34. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Which of these statistics are primarily aimed at analyzing discrete raster data? • Majority, minority, variety • Which of these statistics are primarily aimed at analyzing continuous raster data? • Mean, maximum, median, minimum, range, standard deviation, sum Slide #34
35. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Discrete statistics • Majority • Determines, within the defined neighborhood, what discrete cell value is most common • If a tie, then resulting value is NA Slide #35 G S S S F F W W S F G G G F F W W S F G G G S W W W S F S G G W W W F F S S G W W W G F F F S W W W G G F F S G W W G G S S F S W W W G S S F F W W W G S S S F F G G G G NA W W W W G G G G W W W W W G G G G W W W W W G G G G W W W W F NA G NA W W W W F F S W W W W W F F F W W W W W NA F F F W W W W W S NA F F W W W W S S S S F G grass S shrub F forest W water raw land cover dataset 5x5 rectangle majority filtered land cover dataset edge cell-inclusive edge cell-exclusive
36. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Discrete statistics • Majority • Determines, within the defined neighborhood, what discrete cell value is most common • If a tie, then resulting value is NA • Often used to “clean” or “simplify” pixelated data, such as land cover • Sometimes referred to as the “salt and pepper” effect Slide #36 G S S S F F W W S F G G G F F W W S F G G G S W W W S F S G G W W W F F S S G W W W G F F F S W W W G G F F S G W W G G S S F S W W W G S S F F W W W G S S S F F G G G G NA W W W W G G G G W W W W W G G G G W W W W W G G G G W W W W F NA G NA W W W W F F S W W W W W F F F W W W W W NA F F F W W W W W S NA F F W W W W S S S S F G grass S shrub F forest W water raw land cover dataset 5x5 rectangle majority filtered land cover dataset edge cell-inclusive edge cell-exclusive
37. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Discrete statistics • Minority • Determines, within the defined neighborhood, what discrete cell value is least common • If a tie, then resulting value is NA • e.g. finding rare, isolated land cover types Slide #37 G S S S F F W W S F G G G F F W W S F G G G S W W W S F S G G W W W F F S S G W W W G F F F S W W W G G F F S G W W G G S S F S W W W G S S F F W W W G S S S F F NA F NA W S NA NA F NA NA F W W S S NA S F F W W F S S G G G W W NA F S S NA S NA W F F NA S NA S S G F F F NA S NA S W W F F F NA NA S W W G NA F F NA NA F W G G G NA S S NA NA G G NA G grass S shrub F forest W water raw land cover dataset 5x5 rectangle minority filtered land cover dataset edge cell-inclusive edge cell-exclusive
38. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Discrete statistics • Variety • Determines, within the defined neighborhood, the number of unique, discrete cell values • e.g. finding out how fragmented habitats are Slide #38 G S S S F F W W S F G G G F F W W S F G G G S W W W S F S G G W W W F F S S G W W W G F F F S W W W G G F F S G W W G G S S F S W W W G S S F F W W W G S S S F F 3 3 3 4 4 4 3 3 2 3 3 4 4 4 4 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 3 3 4 4 4 4 4 4 4 3 3 4 4 4 4 4 4 4 3 3 4 4 4 3 4 4 4 3 3 4 4 3 3 3 3 3 3 3 4 3 3 2 G grass S shrub F forest W water raw land cover dataset 5x5 rectangle land cover variety edge cell-inclusive edge cell-exclusive
39. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Mean • Determines, within the defined neighborhood, the average of continuous cell values • Smooths out your data • e.g. removing artifacts from a bad DEM Slide #39 raw elevation dataset 5x5 rectangle elevation mean filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 27.5 27.7 28.0 28.5 28.9 29.1 29.3 29.4 29.4 27.7 27.9 28.1 28.5 28.8 28.9 29.1 29.1 29.1 28.1 28.2 28.4 28.6 28.8 28.8 29.0 29.0 29.0 28.5 28.6 28.6 28.7 28.6 28.6 28.6 28.6 28.7 28.9 28.9 28.8 28.6 28.4 28.2 28.2 28.2 28.4 29.2 29.2 28.9 28.6 28.2 28.0 27.9 27.9 28.1 29.2 29.1 28.8 28.4 28.0 27.7 27.7 27.7 27.9 29.1 29.0 28.7 28.3 27.8 27.6 27.5 27.5 27.8 28.9 28.8 28.5 28.1 27.7 27.4 27.4 27.4 27.6
40. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Median • Determines, within the defined neighborhood, the average of continuous cell values • Like mean, smooths out your data, but not as smooth • e.g. continuous measure of median home value in a city Slide #40 raw elevation dataset 5x5 rectangle elevation median filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 27.5 27.9 28.1 28.3 29.1 29.2 29.3 29.4 29.6 27.6 28.1 28.2 28.4 28.8 29.1 29.2 29.2 29.2 28.1 28.2 28.3 28.5 28.7 29.0 29.1 29.2 29.2 28.4 28.6 28.5 28.5 28.5 28.5 28.5 28.7 28.9 29.2 29.2 28.9 28.6 28.3 28.2 28.2 28.2 28.4 29.2 29.2 29.0 28.7 28.2 27.9 27.9 28.0 28.1 29.2 29.2 28.9 28.4 27.8 27.6 27.6 27.7 27.9 29.2 29.1 28.7 28.3 27.5 27.5 27.5 27.5 27.8 29.0 28.7 28.6 28.3 27.5 27.5 27.5 27.4 27.7
41. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Minimum • Determines, within the defined neighborhood, the minimum of continuous cell values • e.g. finding the lowest average pollution areas in a city Slide #41 raw elevation dataset 5x5 rectangle elevation minimum filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 26.6 26.6 26.6 27.4 27.6 28.2 28.4 28.4 28.4 26.6 26.6 26.6 27.4 27.6 28.1 28.1 28.1 28.1 26.6 26.6 26.6 27.4 27.6 27.6 27.6 27.6 27.6 26.6 26.6 26.6 27.1 27.1 27.1 27.1 27.1 27.5 27.0 27.0 27.0 26.9 26.9 26.9 26.9 26.9 27.3 27.7 27.7 27.2 26.7 26.7 26.7 26.7 26.7 26.7 28.3 28.2 27.2 26.3 26.3 26.3 26.3 26.3 26.6 28.3 28.2 27.2 26.3 26.3 26.3 26.3 26.3 26.6 28.3 28.2 27.2 26.3 26.3 26.3 26.3 26.3 26.6
42. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Maximum • Determines, within the defined neighborhood, the maximum of continuous cell values • e.g. finding the highest snow totals in the mountains Slide #42 raw elevation dataset 5x5 rectangle elevation maximum filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 28.1 28.5 29.3 29.9 29.9 29.9 30.1 30.1 30.1 28.7 29.3 29.3 29.9 29.9 29.9 30.1 30.1 30.1 30.0 30.0 30.0 30.0 30.0 29.9 30.1 30.1 30.1 30.0 30.0 30.0 30.0 30.0 29.9 29.9 29.9 29.6 30.0 30.0 30.0 30.0 30.0 29.5 29.6 29.6 29.6 30.0 30.0 30.0 30.0 30.0 29.5 29.6 29.6 29.6 30.0 30.0 30.0 30.0 30.0 29.5 29.6 29.6 29.6 29.8 29.8 29.8 29.8 29.8 29.4 28.9 28.9 28.9 29.5 29.5 29.5 29.5 29.5 28.8 28.6 28.6 28.6
43. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Range • Determines, within the defined neighborhood, the range (max – min) of continuous cell values • e.g. finding the “rough” or “variable” areas of a landscape Slide #43 raw elevation dataset 5x5 rectangle elevation range filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 1.6 1.9 2.8 2.5 2.3 1.6 1.7 1.7 1.7 2.1 2.7 2.8 2.5 2.3 1.8 2.0 2.0 2.0 3.4 3.4 3.4 2.6 2.4 2.2 2.5 2.5 2.5 3.4 3.4 3.4 2.9 2.9 2.7 2.7 2.7 2.1 3.0 3.0 3.0 3.1 3.1 2.6 2.7 2.7 2.3 2.3 2.3 2.8 3.3 3.3 2.8 3.0 3.0 2.9 1.7 1.8 2.8 3.7 3.7 3.2 3.3 3.3 3.0 1.4 1.5 2.6 3.4 3.4 3.1 2.6 2.6 2.3 1.2 1.3 2.4 3.2 3.2 2.5 2.3 2.3 2.0
44. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Standard deviation • Determines, within the defined neighborhood, the standard deviation of continuous cell values • How variable cell values are within a neighborhood • e.g. finding rough terrain Slide #44 raw elevation dataset 5x5 rectangle elevation SD filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 0.5 0.6 0.8 0.7 0.7 0.5 0.4 0.4 0.5 0.6 0.7 0.8 0.7 0.6 0.6 0.6 0.6 0.6 0.9 0.9 0.9 0.7 0.7 0.6 0.7 0.7 0.7 1.1 1.0 0.9 0.9 0.8 0.7 0.7 0.8 0.7 0.9 0.9 0.9 0.9 0.9 0.7 0.7 0.8 0.7 0.6 0.6 0.8 1.0 1.0 0.8 0.7 0.8 0.7 0.5 0.5 0.8 1.1 1.1 0.8 0.8 0.8 0.8 0.5 0.5 0.8 1.1 1.0 0.8 0.7 0.7 0.7 0.5 0.4 0.7 1.0 1.0 0.7 0.7 0.7 0.7
45. Focal Operations in ArcGIS • Focal analysis tools • Focal Statistics • Statistics type • Continuous statistics • Sum • Determines, within the defined neighborhood, the sum of continuous cell values • e.g. total number of trees within a given area Slide #45 raw elevation dataset 5x5 rectangle elevation sum filter edge cell-inclusive edge cell-exclusive elevation (m) 26.3 30.1 27.0 28.1 28.1 28.2 29.1 29.2 29.7 29.7 30.1 26.6 27.4 28.1 28.5 29.1 29.9 29.6 29.3 29.6 27.0 27.5 27.6 28.3 29.3 29.2 29.0 28.4 29.1 27.7 28.4 28.7 29.3 28.5 28.2 28.1 28.1 29.2 28.9 29.7 30.0 29.5 28.2 27.8 27.6 28.5 29.6 29.6 29.8 29.8 29.4 27.8 27.1 27.5 28.2 28.9 29.2 29.5 29.5 28.6 27.5 26.9 27.3 27.5 28.6 28.7 29.0 29.2 28.8 27.2 26.7 26.7 27.9 28.4 28.3 28.3 28.4 28.2 27.5 26.3 26.6 27.7 28.0 0.5 0.6 0.8 0.7 0.7 0.5 0.4 0.4 0.5 0.6 0.7 0.8 0.7 0.6 0.6 0.6 0.6 0.6 0.9 0.9 0.9 0.7 0.7 0.6 0.7 0.7 0.7 1.1 1.0 0.9 0.9 0.8 0.7 0.7 0.8 0.7 0.9 0.9 0.9 0.9 0.9 0.7 0.7 0.8 0.7 0.6 0.6 0.8 1.0 1.0 0.8 0.7 0.8 0.7 0.5 0.5 0.8 1.1 1.1 0.8 0.8 0.8 0.8 0.5 0.5 0.8 1.1 1.0 0.8 0.7 0.7 0.7 0.5 0.4 0.7 1.0 1.0 0.7 0.7 0.7 0.7 247.5 332.5 420.0 427.7 432.9 436.5 440.2 352.7 264.4 332.2 446.5 562.6 570.8 575.7 578.7 582.3 466.3 349.8 420.8 564.6 708.9 716.0 718.8 720.3 724.1 579.8 435.6 426.8 571.7 714.7 717.0 716.0 714.2 715.6 572.7 430.6 432.9 578.0 719.3 716.0 710.7 705.7 706.1 564.7 425.6 437.6 583.1 722.3 714.8 705.8 698.8 698.0 558.8 422.1 437.8 582.3 720.5 710.5 700.1 693.0 692.0 553.8 419.0 349.2 464.3 574.2 565.3 557.0 551.4 550.2 440.3 333.3 260.1 345.7 427.8 421.5 415.3 411.3 410.7 328.6 248.7
46. For Wednesday’s Class… Read pages 462 - 484 on focal, zonal, global operations