lesto tools in jgrasstoolbox

Estimating forest structure and biomass through LiDAR data:

the L.E.S.T.O. toolbox

Andrea Antonello, Franceschi Silvia, Floreancig Valentino, Comiti Francesco, Tonon Giustino

FOSS4G Osaka October 2014

INTRODUCTION

● co-founder of HydroloGIS with Andrea Antonello

● environmental engineer specialized in hydrology, hydraulics and geomorphology

● PhD student of Science and Technology at the University of Bolzano (Italy)

● developed scientific models contained in the JGrassTools library in the field of:

– hydrology

– hydraulics

– forestry● OSGeo Charter Member

JGRASSTOOLS

● geospatial library containing modules for:

– vector and raster processing

– geomorphology

– forestry

– mobile mapping support● it is the core behind the Spatial Toolbox of uDig GIS

● it can be used stand alone using the Stage (http://bit.ly/stage_downloads): Spatial Toolbox And Geoscripting Ennvironment tool for environmental modelling

JGRASSTOOLS

WHAT IS LESTO?

● Open Source

● GIS aware

● library dedicated to

● sciences that make use of

● LiDAR data

Developed and maintained by HydroloGIS and the team of prof. Tonon at the Faculty of Science and Technology of the Free University of Bolzano (Italy).

Contains tools for handling high resolution LiDAR data (LAS) and for LiDAR analysis related to forestry.

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Rasterlas interpolation

- DTM- DSM

- CHM

Filterslas height distribution

las histogram

las merge

las threshold

Tools

Buildin

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Fores

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MODULES OVERVIEW

MODULES OVERVIEW IN STAGE

PREPROCESSING

Packages including the available pre-processing operations are:

● Utilities

– LasIndexer: creates indexes for LAS files

LasIndexer

PREPROCESSING

Packaging including the available pre-processing operations are:

● Utilities


– LasInfo: prints out information of a LAS file/folder

LasInfo

PREPROCESSING


● Utilities



– LasOverviewCreator: creates a shp with overview

LasOverviewCreator

PREPROCESSING


● Utilities



– LasOverviewCreator: creates a shp with overview

– LasPointDensityExtractor: creates a shp with point cloud density on a given grid

LasPointDensityExtractor

PREPROCESSING


● Utilities

– LasIndexer

– LasInfo

– LasOverviewCreator

– LasPointDensityExtractor● Filter

– LasHeightDistribution: analyze the height distribution and categorize the forest type

LasHeightDistribution

PREPROCESSING


● Utilities

– LasIndexer

– LasInfo



– LasHeightDistribution

– LasHistogram: creates an histogram of the elevation or intensity of all the points in the LAS file

LasHistogram

PREPROCESSING


● Utilities

– LasIndexer

– LasInfo




– LasHistogram

– LasMerger: merges all the LAS file contained in a folder in a single one

LasMerger

PREPROCESSING


● Utilities

– LasIndexer

– LasInfo




– LasHistogram

– LasMerger

– LasThresholder: extracts the points with values in an interval

LasThresholder

RASTER

Raster package contains all the available modules to interpolate and create a raster (DTM, DSM) from raw point cloud. The different interpolation algorithms are

● AdaptiveTinFilter: the implementation of the adaptive TIN method of Axelsons

● Las2BivariateRasterMosaic: uses the bivariate function to interpolate a raster from the point cloud and creates a mosaic of TIF

● Las2RasterInterpolator: interpolates a raster from LAS points using the Inverse Distance Weight method

● LasOnRasterMapper: creates a raster by mapping max/min elevation point in each pixel

● LasTriangulation2Dsm: creates a DSM from the triangulation of the point cloud

RASTER

ADAPTIVE TIN

RASTER

MAX HEIGHT

BUILDINGS

This package contains a module to extract the vector data of the buildings from a LAS file.

● LasOnDtmBuildingExtractor: based on the identification of the holes in the ground generated by cutting all the points with an elevation on the ground over a given threshold

● the output shapefile can be cleaned from noise data and smoothed on the boundaries

BUILDINGS

FLIGHTLINES

Modules to separate different flightlines inside a LAS file:

● FlightLinesExtractor: creates different las files for each of the different flightlines inside the single las

FLIGHTLINES

FLIGHTLINES

Modules to separate different flightlines inside a LAS file:

● FlightLinesExtractor: creates different las files for each of the different flightlines inside the single las

● FlightLinesIntensityNormalizer: normalize intensity values between different flightlines considering the position of the aircraft (x,y,z)

FLIGHTLINES

VEGETATION

Extrapolation of the whole forest biometric data (e.g. forest biomass) can be obtained through two approaches:

● area-based approaches (AB): forest attributes are estimated by relating plot data to ALS data by statistically procedure

● individual tree crown (ITC) approaches: can use both raster CHM and point ALS data and are aimed to detect position and main characteristics of each single tree. Single-tree records can then be aggregated at plot, forest, watershed or regional scale.

VEGETATION

Extrapolation of the whole forest biometric data (e.g. forest biomass) can be obtained through two approaches:

● area-based approaches (AB): forest attributes are estimated by relating plot data to ALS data by statistically procedure

● individual tree crown (ITC) approaches: ITC approaches can use both raster CHM and point ALS data and are aimed to detect position and main characteristics of each single tree. Single-tree records can then be aggregated at plot, forest, watershed or regional scale.

VEGETATION

The position of trees and vegetation information are used to evaluate:

● the forest structure

● the volume of biomass

● the source of hydro-geological hazard related to

– hillslopes stability

– transport of wood in rivers.

STUDY AREA: DESCRIPTION

high local variety in forest structure

AURINA VALLEY

VEGETATION:●Norway spruce (Picea abies)●Larch (Larix decidua)●Stone pine (Pinus cembra)

AREA = 10 km2

STUDY AREA: LiDAR SURVEY (2012)

points classification

points difference DTM

DTM + DSM

points density = 10 p/m2

12 CIRCULAR PLOTS

AREA = 0.07 ha

RADIUS = 15 m

BUFFER 150 m ROADS

FOREST STRUCTURES:●young●biplane●adult●multilayer

STUDY AREA: FIELD SURVEY (2013)

ALLOMETRIC RELATIONSHIPS

V(tree) = f(h,DBH)

STUDY AREA: FIELD SURVEY (2013)

Sample plots: forest metrics

VEGETATION MODULES

The available modules for single tree extraction are based on the identification of local maxima:

● RasterMaximaFinder: identifies local maxima on raster input data

RasterMaximaFinder

VEGETATION MODULES



● PointCluodMaximaFinder: identifies local maxima on point cloud input data

PointCloudMaximaFinder

VEGETATION MODULES



● PointCluodMaximaFinder: identifies local maxima on point cloud input data

● WatershedAlgorithm: delineates the crowns of the trees based on raster data

WatershedAlgorithm

● stabilize and release some new algorithms of pre/post processing of extracted maximum points to improve the results

● implement Particle Swarming Optimizer for automatic calibration of the models

● integrate a visualizer for LAS point data● use the results in the models for the evaluation of

the hazard related to transport of wood during floods

FUTURE PLANS

LESTO is released under Open Source License (GPL v3) on the JGrasstools website.

The toolbox is open to contributions on any LiDAR related (future might even bring roads or power lines).

LICENCE AND DISTRIBUTION

http://www.jgrasstools.orghttp://bit.ly/stage_downloadshttp://www.udig.eu

USEFUL LINKS

lesto tools in jgrasstoolbox

Environment