Lidar metrics#

Here are a list of all lidar metrics that are available in lidar metrics processing algorithms. For each metric there is a set of parameters (if there is parameters) and a list of outputs. These outputs can be available or not depending the output format (raster or vector), this information are given by the columns Vector and Raster. There is multiple types of metrics so each metric will be tagged with specific badges described below.

Badge

Description

Raster

Available with raster output.

Vector

Available with vector output.

Strata

Metric computed per strata.

Voxels

Voxel based metric.

Points

Point based metric.

Outputs for strata metrics are duplicated for all the strata. Output for a specific strata is: S_{lower_bound}:{upper_bound}_{output_name}. For the lower stratum the lower_bound is min and for the higher stratum the upper_bound is max to contain all points of lidar point cloud.

Canopy Cover#

Points Vector

Compute the canopy cover using a map of small cells. A cell is considered as canopy cell if there is at least one point of lidar poit cloud that is a first return and got a height higher or equal to canopy minimum size. Open/close morpholigical operations are applied to make canopy cover more realistic.

Parameters#

Name

Type

Description

Map resolution

[numeric: double]
Default: 0.1

Cell size for canopy map.

Canopy minimum height

[numeric: double]
Default: 1.30

Minimum height to consider a point as canopy point.

Open size

[numeric: integer]
Default: 13

Size in pixels for morphological opening operation.

Close size

[numeric: integer]
Default: 21

Size in pixels for morphological closing operation.

Outputs#

Name

Type

Description

Vector

Raster

CanopyCover

[numeric: double]

Canopy cover fraction. Value between 0 and 100.

Yes

No

Canopy Relief Ratio#

Points Vector Raster

Canopy Relief-Ratio (CRR) is a quantitative descriptor of the relative shape of the canopy from altimetry observation (Geoffrey Parker & all).

\[\begin{split} CRR = \frac{H_{mean}-H_{min}}{H_{max}-H_{min}}\\ \end{split}\]

Where \(H\) is points heights.

Outputs#

Name

Type

Description

Vector

Raster

CRR

[numeric: double]

Canopy relief ratio. Value between 0 and 1.

Yes

Yes

Effective Number of Layers#

Voxels Vector Raster

Compute the Effective Number of Layers (Martin Ehbrech & all).

\[ ENL = \frac{1}{\sum_{n=1}^{n=N} (\frac{F_{n}}{T})^2} * V_{z} \]

Where:

  • \(N\) is Number of voxels strata that contain at least one filled voxel

  • \(F_{n}\) is the number of filled voxels for stratum i

  • \(T\) is the total of filled voxels for all strata

  • \(V_{z}\) is the voxels height

Outputs#

Name

Type

Description

Vector

Raster

ENL

[numeric: double]

Effective Number of layers.

Yes

Yes

Foliage Height Diversity#

Points Vector Raster

\[ FHD = -\sum_{i=1}^{i=N} pi * \log{pi} \]

Where:

  • \(p_i\) is the proportion of points that lies in the stratum i

  • \(N\) is the number of strata where \(p_i\) > 0

Outputs#

Name

Type

Description

Vector

Raster

FHD

[numeric: double]

Foliage Height Diversity.

Yes

Yes

Height peaks estimation#

Points Vector Raster

Compute number of modes, maximum mode height, minimum mode height and mode height range from a kernel density estimation of height probability function.

Outputs#

Name

Type

Description

Vector

Raster

KDE_n_modes

[numeric: double]

Number of modes.

Yes

Yes

KDE_min_mode

[numeric: double]

Minimum height mode.

Yes

Yes

KDE_max_mode

[numeric: double]

Maximum height mode.

Yes

Yes

KDE_mode_range

[numeric: double]

Range between minimum and maximum height modes.

Yes

Yes

Statistics on L moments of heights#

Points Vector Raster

Compute coefficient of variation, Skewness and Kurtosis of the L moments of points heights.

Outputs#

Name

Type

Description

Vector

Raster

Height L Moments cv

[numeric: double]

Coefficient of variation of L moments of heights.

Yes

Yes

Height LMoments skewness

[numeric: double]

Skewness of L moments of heights.

Yes

Yes

Height LMoments kurtosis

[numeric: double]

Kurtosis of L moments of heights.

Yes

Yes

Statistics on L moments of intensities#

Points Vector Raster

Compute coefficient of variation, Skewness and Kurtosis of the L moments of points intensity.

Outputs#

Name

Type

Description

Vector

Raster

Intensity L Moments cv

[numeric: double]

Coefficient of variation of L moments of intensities.

Yes

Yes

Intensity LMoments skewness

[numeric: double]

Skewness of L moments of intensities.

Yes

Yes

Intensity LMoments kurtosis

[numeric: double]

Kurtosis of L moments of intensities.

Yes

Yes

Mean Outer Canopy Height#

Points Vector Raster

Compute the Mean Outer Canopy Height as the mean of first returns points heights with the assumption that first returns points do not enter the canopy and are representative of the outer surface area (Jeff W. Atkins & all).

Outputs#

Name

Type

Description

Vector

Raster

MOCH

[numeric: double]

Mean Outer Canopy Height.

Yes

Yes

Plant Area Density#

Voxels Vector Raster

Compute Plant Area Density and derivated metrics. This si a simplified PAD metric computed using gap fraction (Olivier Martin & all).

\[\begin{split} \begin{array}{l} NRD_{x,y,z} = \frac{N_{x,y,z}}{\sum_{i=0}^z N_{x,y,i}} \\[0.8em] GF_{x,y,z} = 1 - NRD_{x,y,z} \\[0.8em] PAD_{x,y,z} = \frac{-\ln(GF_{x,y,z})}{G(\theta) \times D} \end{array} \end{split}\]

where:

  • \(N_{x,y,z}\) is the number of hits in voxel \(V_{x,y,z}\)

  • \(NRD_{x,y,z}\) is the normalized return index

  • \(GF_{x,y,z}\) Is the gap fraction

Parameters#

Name

Description

Type

K

K coefficient performs an inverse linear calibration of LAD (Leaf Area Density) to a known LAI (Leaf Area Index) and represent vegetation efficiency to intercept lidar laser.

[numeric: double]
Default: 1

Outputs#

Name

Type

Description

Vector

Raster

PAD_mean

[numeric: double]

Plant Area Density mean.

Yes

Yes

PAD_min

[numeric: double]

Plant Area Density minimum.

Yes

Yes

PAD_max

[numeric: double]

Plant Area Density maximum.

Yes

Yes

PAD_sd

[numeric: double]

Plant Area Density standard deviation.

Yes

Yes

PAD_var

[numeric: double]

Plant Area Density variance.

Yes

Yes

PAD_cv

[numeric: double]

Plant Area Density coefficient of variation.

Yes

Yes

PAI

[numeric: double]

Plant Area Index.

No

Yes

PAI_mean

[numeric: double]

Plant Area Index mean.

Yes

No

PAI_min

[numeric: double]

Plant Area Index minimum.

Yes

No

PAI_max

[numeric: double]

Plant Area Index maximum.

Yes

No

PAI_sd

[numeric: double]

Plant Area Index standard deviation.

Yes

No

PAI_var

[numeric: double]

Plant Area Index variance.

Yes

No

PAI_cv

[numeric: double]

Plant Area Index coefficient of variation.

Yes

No

PAD_mean_of_ver_sd

[numeric: double]

Plant Area Density mean of vertical standard deviation.

Yes

No

PAD_mean_of_ver_cv

[numeric: double]

Plant Area Density mean of vertical coefficient of variation.

Yes

No

PAD_sd_of_ver_mean

[numeric: double]

Plant Area Density standard deviation of vertical mean.

Yes

No

PAD_cv_of_ver_mean

[numeric: double]

Plant Area Density coefficient of variation of vertical mean.

Yes

No

PAD_mean_of_hor_sd

[numeric: double]

Plant Area Density mean of horizontal standard deviation.

Yes

No

PAD_mean_of_hor_cv

[numeric: double]

Plant Area Density mean of horizontal coefficient of variation.

Yes

No

PAD_sd_of_hor_mean

[numeric: double]

Plant Area Density standard deviation of horizontal mean.

Yes

No

PAD_cv_of_hor_mean

[numeric: double]

Plant Area Density coefficient of variation of horizontal mean.

Yes

No

VCI

[numeric: double]

Vertical Complexity Index.

No

Yes

VCI_mean

[numeric: double]

Vertical Complexity Index mean.

Yes

No

VCI_min

[numeric: double]

Vertical Complexity Index minimum.

Yes

No

VCI_max

[numeric: double]

Vertical Complexity Index maximum.

Yes

No

VCI_sd

[numeric: double]

Vertical Complexity Index standard deviation.

Yes

No

VCI_var

[numeric: double]

Vertical Complexity Index variance.

Yes

No

VCI_cv

[numeric: double]

Vertical Complexity Index coefficient of variation.

Yes

No

PAD_peak_height

[numeric: double]

Height of Plant Area Density peak.

Yes

Yes

PAD_skewness

[numeric: double]

Skewness of Plant Area Density distribution.

Yes

Yes

PAD_kurtosis

[numeric: double]

Kurtosis of Plant Area Density distribution.

Yes

Yes

PAD_Z_P25

[numeric: double]

Percentile 25 of Plant Area Density distribution.

Yes

Yes

PAD_Z_P50

[numeric: double]

Percentile 50 of Plant Area Density distribution.

Yes

Yes

PAD_Z_P75

[numeric: double]

Percentile 75 of Plant Area Density distribution.

Yes

Yes

PAD_mean_slope

[numeric: double]

Mean of Plant Area Density slope.

Yes

Yes

PAD_max_slope

[numeric: double]

Maximum of Plant Area Density slope.

Yes

Yes

PAD_min_slope

[numeric: double]

Minimum of Plant Area Density slope

Yes

Yes

PAD_mean_curvature

[numeric: double]

Minimum of Plant Area Density curvature.

Yes

Yes

PAD_max_curvature

[numeric: double]

Maximum of Plant Area Density slope.

Yes

Yes

PAD_num_inflection_points

[numeric: double]

Number of inflection points in Plant Area Density distribution.

Yes

Yes

Percentiles of height#

Points Vector Raster

Compute the following percentiles on points heights: 1, 5, 10, 20, 25, 30, 40, 50, 60, 70, 75, 80, 90, 95, 99.

Outputs#

Name

Type

Description

Vector

Raster

Height percentile_1

[numeric: double]

1st height percentile.

Yes

Yes

Height percentile_5

[numeric: double]

5th height percentile.

Yes

Yes

Height percentile_10

[numeric: double]

10th height percentile.

Yes

Yes

Height percentile_20

[numeric: double]

20th height percentile.

Yes

Yes

Height percentile_25

[numeric: double]

25th height percentile.

Yes

Yes

Height percentile_30

[numeric: double]

30th height percentile.

Yes

Yes

Height percentile_40

[numeric: double]

40th height percentile.

Yes

Yes

Height percentile_50

[numeric: double]

50th height percentile.

Yes

Yes

Height percentile_60

[numeric: double]

60th height percentile.

Yes

Yes

Height percentile_70

[numeric: double]

70th height percentile.

Yes

Yes

Height percentile_75

[numeric: double]

75th height percentile.

Yes

Yes

Height percentile_80

[numeric: double]

80th height percentile.

Yes

Yes

Height percentile_90

[numeric: double]

90th height percentile.

Yes

Yes

Height percentile_95

[numeric: double]

95th height percentile.

Yes

Yes

Height percentile_99

[numeric: double]

99th height percentile.

Yes

Yes

Percentiles of intensity#

Points Vector Raster

Compute the following percentiles on points intensities: 1, 5, 10, 20, 25, 30, 40, 50, 60, 70, 75, 80, 90, 95, 99.

Outputs#

Name

Type

Description

Vector

Raster

Intensity percentile_1

[numeric: double]

1st intensity percentile.

Yes

Yes

Intensity percentile_5

[numeric: double]

5th intensity percentile.

Yes

Yes

Intensity percentile_10

[numeric: double]

10th intensity percentile.

Yes

Yes

Intensity percentile_20

[numeric: double]

20th intensity percentile.

Yes

Yes

Intensity percentile_25

[numeric: double]

25th intensity percentile.

Yes

Yes

Intensity percentile_30

[numeric: double]

30th intensity percentile.

Yes

Yes

Intensity percentile_40

[numeric: double]

40th intensity percentile.

Yes

Yes

Intensity percentile_50

[numeric: double]

50th intensity percentile.

Yes

Yes

Intensity percentile_60

[numeric: double]

60th intensity percentile.

Yes

Yes

Intensity percentile_70

[numeric: double]

70th intensity percentile.

Yes

Yes

Intensity percentile_75

[numeric: double]

75th intensity percentile.

Yes

Yes

Intensity percentile_80

[numeric: double]

80th intensity percentile.

Yes

Yes

Intensity percentile_90

[numeric: double]

90th intensity percentile.

Yes

Yes

Intensity percentile_95

[numeric: double]

95th intensity percentile.

Yes

Yes

Intensity percentile_99

[numeric: double]

99th intensity percentile.

Yes

Yes

Returns proportion#

Points Vector Raster

Compute population and proportion of returns and first returns with heights above mean height.

Outputs#

Name

Type

Description

Vector

Raster

Returns above mean height

[numeric: double]

Number of returns with height above mean height.

Yes

Yes

Returns above mean height percentage

[numeric: double]

Proportion of returns with height above mean height.

Yes

Yes

First returns above mean height

[numeric: double]

Number of first returns with height above mean height.

Yes

Yes

First returns above mean height percentage

[numeric: double]

Proportion of first returns with height above mean height.

Yes

Yes

Rugosity#

Points Vector Raster

Compute Rugosity as the standard deviation of outer canopy heights using first returns only. Rugosity provides an assessment of heterogeneity based on the variability of the system (Jeff W. Atkins & all).

Outputs#

Name

Type

Description

Vector

Raster

Rugosity

[numeric: double]

Standard deviation of outer canopy heights.

Yes

Yes

Statistics of height#

Points Vector Raster

Compute basic statistics on points height distribution.

Outputs#

Name

Type

Description

Vector

Raster

Heights_min

[numeric: double]

Minimum height.

Yes

Yes

Heights_max

[numeric: double]

Maximum height.

Yes

Yes

Heights_mean

[numeric: double]

Height mean.

Yes

Yes

Heights_median

[numeric: double]

Height median.

Yes

Yes

Heights_mode

[numeric: double]

Height mode (peak).

Yes

Yes

Heights_std

[numeric: double]

Height standard deviation.

Yes

Yes

Heights_var

[numeric: double]

Height variance.

Yes

Yes

Heights_cv

[numeric: double]

Coefficient of variation of height.

Yes

Yes

Heights_iqr

[numeric: double]

Height interquartile range.

Yes

Yes

Heights_skewness

[numeric: double]

Skewness of height.

Yes

Yes

Heights_kurtosis

[numeric: double]

Kurtosis of height.

Yes

Yes

Heights_aad

[numeric: double]

Average absolute deviation of heights.

Yes

Yes

Heights_mad_median

[numeric: double]

Mean absolute deviation from height median.

Yes

Yes

Heights_mad_mode

[numeric: double]

Mean absolute deviation from height mode.

Yes

Yes

Heights_quadratic_mean

[numeric: double]

Quadratic mean of heights.

Yes

Yes

Statistics of intensity#

Points Vector Raster

Compute basic statistics on points intensitiy distribution.

Outputs#

Name

Type

Description

Vector

Raster

Intensity_min

[numeric: double]

Minimum intensity.

Yes

Yes

Intensity_max

[numeric: double]

Maximum intensity.

Yes

Yes

Intensity_mean

[numeric: double]

Intensity mean.

Yes

Yes

Intensity_median

[numeric: double]

Intensity median.

Yes

Yes

Intensity_mode

[numeric: double]

Intensity mode (peak).

Yes

Yes

Intensity_std

[numeric: double]

Intensity standard deviation.

Yes

Yes

Intensity_var

[numeric: double]

Intensity variance.

Yes

Yes

Intensity_cv

[numeric: double]

Coefficient of variation of intensity.

Yes

Yes

Intensity_iqr

[numeric: double]

Intensity interquartile range.

Yes

Yes

Intensity_skewness

[numeric: double]

Skewness of intensity.

Yes

Yes

Intensity_kurtosis

[numeric: double]

Kurtosis of intensity.

Yes

Yes

Intensity_aad

[numeric: double]

Average absolute deviation of intensity.

Yes

Yes

Intensity_mad_median

[numeric: double]

Mean absolute deviation from intensity median.

Yes

Yes

Intensity_mad_mode

[numeric: double]

Mean absolute deviation from intensity mode.

Yes

Yes

Intensity_quadratic_mean

[numeric: double]

Quadratic mean of intensity.

Yes

Yes

Strata returns proportions#

Points Vector Raster Strata

Compute population and proportion of returns and first returns per stratum.

Outputs#

Name

Type

Description

Vector

Raster

returns

[numeric: double]

Number of returns.

Yes

Yes

returns_proportion

[numeric: double]

Proportion of returns.

Yes

Yes

returns_above_lower_bound

[numeric: double]

Percentage of returns above lower bound of stratum.

Yes

Yes

percentage_of_returns_above_lower_bound

[numeric: double]

Number of first returns.

Yes

Yes

first_returns_above_lower_bound

[numeric: double]

Proportion of first returns.

Yes

Yes

percentage_of_first_returns_above_lower_bound

[numeric: double]

Percentage of first returns above lower bound of stratum.

Yes

Yes

density_proportion

[numeric: double]

Proportion of total vegetation that lies in current stratum.

Yes

Yes

Heights strata statistics#

Points Vector Raster Strata

Compute statistics on points heights for each stratum.

Outputs#

Name

Type

Description

Vector

Raster

Heights std

[numeric: double]

Heights standard deviation.

Yes

Yes

Heights var

[numeric: double]

Heights variance.

Yes

Yes

Heights cv

[numeric: double]

Coefficient of variation of height.

Yes

Yes

Heights skewness

[numeric: double]

Skewness of heights.

Yes

Yes

Heights kurtosis

[numeric: double]

Kurtosis of heights.

Yes

Yes

Heights min

[numeric: double]

Minimum height.

Yes

Yes

Heights max

[numeric: double]

MAximum height.

Yes

Yes

Heights mean

[numeric: double]

Heights mean.

Yes

Yes

Heights median

[numeric: double]

Median of heights.

Yes

Yes

Intensities strata statistics#

Points Vector Raster Strata

Compute statistics on points intensities for each stratum.

Outputs#

Name

Type

Description

Vector

Raster

Intensities std

[numeric: double]

Intensities standard deviation.

Yes

Yes

Intensities var

[numeric: double]

Intensities variance.

Yes

Yes

Intensities cv

[numeric: double]

Coefficient of variation of intensities.

Yes

Yes

Intensities skewness

[numeric: double]

Skewness of intensities.

Yes

Yes

Intensities kurtosis

[numeric: double]

Kurtosis of intensities.

Yes

Yes

Intensities min

[numeric: double]

Minimum intensity.

Yes

Yes

Intensities max

[numeric: double]

MAximum intensity.

Yes

Yes

Intensities mean

[numeric: double]

Intensity mean.

Yes

Yes

Intensities median

[numeric: double]

Intensity median.

Yes

Yes