Table 4 List of height features.
Features | Definition/formula |
|---|---|
Hmax | Maximum height |
Hmean | Mean height |
Hmin | Minimum height |
Hmed | Median height |
Hmed_z | Median of median absolute deviation |
Hcv | Coefficient of variation.\(\frac{{Z_{{{\text{s}}td}} }}{{Z_{mean} }} \times 100\%\) |
Hkur | Kurtosis of height. Flatness of height distribution for all points in a statistical unit |
Hske | Skewness of height. The distortion or symmetry state of a height frequency distribution curve |
HAAD | Average absolute deviation,\(\frac{{\sum\nolimits_{i = 1}^{n} {\left( {\left| {Z_{i} - \overline{Z} } \right|} \right)} }}{n}\) |
HAIH (15) | Point clouds are sorted according to elevation. AIHX is the height of a laser point that ranks in the Xth% position in the accumulative curve |
Hper (15) | Point clouds are sorted according to elevation. HX is the height of the Xth% point |
HIQ | Elevation percentile interquartile distance,\(H75\% - H25\%\) |
HAIH IQ | Interquartile distance of accumulative height,\(AIH75\% - AIH25\%\) |
HCRR | Canopy relief ratio.\(\frac{mean - min}{{max - min}}\) |
HGM2nd | Generalized means for the 2nd power,\(\sqrt[2]{{\frac{{\sum\nolimits_{{i = 1}}^{n} {Z_{i} ^{2} } }}{n}}}\) |
HGM3nd | Generalized means for the 3rd power,\(\sqrt[3]{{\frac{{\sum\nolimits_{i = 1}^{n} {Z_{i}^{3} } }}{n}}}\) |
HStdDev | Standard deviation of height |
HVariance | Height variance |
HD (10) | Density metrics. Point clouds are divided into 10 slices with the same interval from low to high elevation. D[N] is the proportion of points in the Nth slice compared to the total points |
