Table 8 Importance ranking of polygon area index features extracted by three algorithms in tree species classification based on feature sets and the results from WorldView-2

1

2.67

Band 6 MEA

2.32

Band 6

3.28

PAI₃ 7 to 8

2

2.16

Band 6

2.13

Band 1 MEA

2.11

PAI₃ 2 to 3

3

2.11

Band 1 MEA

1.95

Band 3 MEA

2.09

PAI₃ 1 to 3

4

1.91

Band 3 MEA

1.9

PAI₂ 1 to 2

2.02

PAI₃ 3 to 5

5

1.91

Band 3

1.8

Band 6 MEA

2

PAI₃ 4 to 5

6

1.83

Band 1

1.73

Band 1

1.89

Band 1 MEA

7

1.82

Band 5

1.67

Band 4 MEA

1.84

PAI₃ 6 to 7

8

1.69

PAI₁ 1 to 2

1.59

Band 3

1.82

PAI₃ 5 to 6

9

1.63

Band 4 MEA

1.52

Band 2

1.77

PAI₃ 3 to 4

10

1.56

Band 8

1.5

Band 5

1.75

PAI₃ 6 to 8

11

1.4

Band 8 MEA

1.5

Band 8

1.73

PAI₃ 1 to 2

12

1.39

Band 2

1.45

Band 8 MEA

1.7

Band 1

13

1.33

Band 2 MEA

1.35

PAI₂ 3 to 4

1.6

Band 6 MEA

14

1.32

PAI₁ 5 to 6

1.33

PAI₂ 5 to 6

1.57

Band 4 MEA

15

1.31

Band 5 MEA

1.33

Band 5 MEA

1.53

Band 2

16

1.23

PAI₁ 3 to 4

1.3

PAI₂ 1 to 3

1.51

Band 3 MEA

17

1.18

PAI₁ 1 to 3

1.24

Band 2 MEA

1.45

PAI₃ 2 to 5

18

1.15

PAI₁ 4 to 5

1.15

PAI₂ 2 to 4

1.39

Band 2 MEA

19

1.14

PAI₁ 2 to 3

1.15

PAI₂ 2 to 3

1.38

PAI₃ 1 to 5

20

1.09

PAI₁ 7 to 8

1.11

PAI₂ 7 to 8

1.35

PAI₃ 4 to 6

21

1.07

Band 7 MEA

1.08

PAI₂ 4 to 6

1.33

PAI₃ 3 to 6

22

1.07

Band 7

1.05

PAI₂ 4 to 5

1.28

Band 6

23

1.06

PAI₁ 3 to 5

1.01

Band 4

1.22

PAI₃ 2 to 4

24

1.03

PAI₁ 2 to 4

1

PAI₂ 1 to 4

1.22

Band 5 MEA

25

1.01

Band 4

0.96

Band 7

1.22

Band 3

26

0.98

PAI₁ 1 to 8

0.93

PAI₂ 2 to 5

1.17

Band 8

27

0.94

PAI₁ 4 to 6

0.92

Band 7 MEA

1.11

Band 8 MEA

28

0.93

PAI₁ 3 to 6

0.88

PAI₂ 2 to 7

1.07

PAI₃ 1 to 4

29

0.89

PAI₁ 1 to 5

0.85

PAI₂ 6 to 8

1.01

PAI₃ 1 to 6

30

0.83

PAI₁ 5 to 7

0.83

PAI₂ 4 to 8

0.96

PAI₃ 2 to 6

31

0.82

PAI₁ 6 to 8

0.82

PAI₂ 1 to 7

0.9

Band 4

32

0.82

PAI₁ 1 to 4

0.81

PAI₂ 3 to 8

0.79

Band 7 MEA

33

0.78

PAI₁ 5 to 8

0.79

PAI₂ 5 to 8

0.75

Band 5

34

0.78

PAI₁ 2 to 7

0.79

PAI₂ 4 to 7

0.75

Band 7

35

0.77

PAI₁ 2 to 6

0.79

PAI₂ 3 to 5

0.65

PAI₃ 1 to 7

36

0.77

PAI₁ 1 to 7

0.79

PAI₂ 2 to 6

0.64

PAI₃ 5 to 8

37

0.75

PAI₁ 6 to 7

0.79

PAI₂ 1 to 8

0.64

PAI₃ 1 to 8

38

0.75

PAI₁ 2 to 5

0.76

PAI₂ 3 to 6

0.62

PAI₃ 3 to 8

39

0.67

PAI₁ 2 to 8

0.76

PAI₂ 1 to 5

0.61

PAI₃ 4 to 8

40

0.65

PAI₁ 3 to 7

0.71

PAI₂ 2 to 8

0.6

PAI₃ 2 to 8

41

0.64

PAI₁ 3 to 8

0.69

PAI₂ 5 to 7

0.59

PAI₃ 4 to 7

42

0.63

PAI₁ 4 to 8

0.68

PAI₂ 1 to 6

0.57

PAI₃ 5 to 7

43

0.55

PAI₁ 4 to 7

0.64

PAI₂ 6 to 7

0.57

PAI₃ 3 to 7

44

0.54

PAI₁ 1 to 6

0.51

PAI₂ 3 to 7

0.57

PAI₃ 2 to 7