Returns Normalized Difference Vegetation Index (NDVI) values, i.e. (b-a)/(b+a). NDVI values are a measure for the presence and condition of green vegetation.
Syntax
NDVI(Value a, Value b)
Input
Value a | is the satellite band containing visible or red reflectance values |
Domain type: | an Image domain |
Value b | is the satellite band containing near-infrared reflectance values |
Domain type: | an Image domain |
Output
NDVI returns: | a value |
Domain: | system domain Min1to1 |
Value range: | [-1,1] |
Notes:
Tip:
When the definition symbol = is used, a dependent output map or dependent output column is created; when the assignment symbol := is used, the dependency link is immediately broken after the output map/column has been calculated.
Usable in
MapCalc, TabCalc, Simple calculators
Examples
Pocket line calculator examples:
? NDVI(46,78) |
returns 0.258 |
MapCalc example:
OutMap = NDVI(TMBand3,TMBand4)
TMBand3 |
TMBand4 |
OutMap |
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TabCalc example:
OutCol = NDVI(InColA,IncolB)
InColA |
InColB |
OutCol |
18 |
28 |
0.217 |
25 |
30 |
0.091 |
28 |
34 |
0.097 |
? |
39 |
? |
53 |
44 |
-0.092 |
44 |
55 |
0.111 |
80 |
? |
? |
92 |
71 |
-0.129 |
73 |
75 |
0.411 |