Accuracy Assessment
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Accuracy Assessment. Validating an Electronic Land Cover Map. AA_Vis_1. Using the software “MultiSpec,” students follow protocols to prepare a “clustered” image of their GLOBE Study Site. Students examine the “true color” And “false-color Infrared” images - PowerPoint PPT Presentation
Transcript of Accuracy Assessment
AA_Vis_1
Using the software “MultiSpec,” students follow protocols to prepare a “clustered” image
of their GLOBE Study Site
Students examine the “true color”And “false-color Infrared” images
provided by GLOBE to identify land cover types.
AA_Vis_2
Students use the “MUC System” to identify land cover types in their classified image.
Using either a local map,
Or their Landsat image,
Students gather data from 90 x 90
m Qualitative Land Cover Samples to check the
accuracy of their map
.
Site 1MUC 0222 Site 2
MUC 4522
Site 3MUC 93
Site 4MUC 4522
Site 5MUC 52
Site 6MUC 72
Site 7MUC 4522
Site 8MUC 92
At each of these sites, the MUC value is determined, a GPS reading is
taken at the center, and
photographs are taken in
each cardinal direction.
These are Validation
Data
The Accuracy Assessment Data
Work Sheet is filled out for all
sites.
Landing Woods 0222 0222 √
Rachel Carson_1 4522 4522 √
Burnham Plaza 91 93 √
Rachel Carson_2 4522 4522 √
Dunes Development 91 52 √
Wells Beach 72 72 √
Rachel Carson_3 4522 4522 √
Wells Corner 91 92 √
0222 4522 91 92 93 72 52 Total
The “Difference/Error Matrix” is constructed
Validation Data (What we actually found)
Map Data(What we expected
to find)
0222
4522
91
92
93
72
52
Total
0222 4522 91 92 93 72 52 Total
Map and Validation data are entered on the Matrix
Validation Data (What we actually found)
Map Data(What we expected
to find)
0222
4522
91
92
93
72
52
Total
|
| | |
| |
|
|
0222 4522 91 92 93 72 52 Total
Totals are calculated for rows and columns
Validation Data (What we actually found)
Map Data(What we expected
to find)
0222
4522
91
92
93
72
52
Total
|
| | |
| |
|
|
1
3
3
0
0
1
0
81 3 0 1 1 1 1
Overall Accuracy is calculated
Overall Accuracy = -------------------------------------- x 100
Overall Accuracy = ----- x 100 = 63%
Sum of Major Diagonal Tallies
Total Number of Samples
58
Map Data
More Qualitative sites are visited, and the Matrix is developed for all classes on the map
0222 4522 91 92 93 72 52 62 63 Total
0222
4522
91
92
93
72
52
62
63
Total
12
6
8 4 2
5 9 4
81
3
32
3
4
2
3
12
6
14
18
9
3
5
5
7
7912 6 13 16 14 3 3 6 6
MapData
Validation Data
Overall Accuracy is Calculated
Overall Accuracy = --------- x 100 = 72% 5779
Map Data
Validation Data
Producer Accuracy is Calculated
Producer Accuracy tells us how well we did in
identifyingLand cover types in our
map.
Producer Accuracy = ----------------------------- x 100 = -------- = 62% # Correctly Identified
Column Total
813
Validation Data
User Accuracy is Calculated
User Accuracy = ----------------------------- x 100 = -------- = 57% # Correctly Identified
Row Total
814
User Accuracy tells us how accurate someone else
would be using our data in the field
REMOTELY SENSED FOREST VEGETATION MAPS:
RASTER MAPS CREATED FROMLANDSAT TM IMAGERY
July 1996 Landsat TM Image Pawtuckaway Study Area, NH, USA
Forest Cover Type Map from Classification of July 1996 Landsat TM Image Pawtuckaway Study Area, NH, USA
LegendClass Names
White Pine
White Pine-Hemlock
Other Conifer
Hemlock
Oak
Red Maple
Mixed Forest
Nonforest
Beech
Other
ScaleKilometers
AA_Vis_13
ERROR MATRICES ANDESTIMATES OF ACCURACY
AA_Vis_15
