clipLevel2AMGeometry: Clip GEDI Elevation and Height Metrics by Coordinates

In rGEDI: NASA's Global Ecosystem Dynamics Investigation (GEDI) Data Visualization and Processing

Description

This function clips GEDI Level2A extracted Elevation and Height Metrics (Level2AM) within a given bounding coordinates

Usage

clipLevel2AMGeometry(level2AM, polygon_spdf, split_by)

Arguments

level2AM	A GEDI Level2A object (output of readLevel2A function). An S4 object of class "data.table".
polygon_spdf	Polygon. An object of class SpatialPolygonsDataFrame-class, which can be loaded as an ESRI shapefile using raster::shapefile() function in the raster package.
split_by	Polygon id. If defined, GEDI data will be clipped by each polygon using the polygon id from table of attribute defined by the user

Value

Returns an S4 object of class data.table-class containing the clipped elevation and relative heights metrics.

Examples

# Specifying the path to GEDI level2A data (zip file)
outdir = tempdir()
level2A_fp_zip <- system.file("extdata",
                  "GEDI02_A_2019108080338_O01964_T05337_02_001_01_sub.zip",
                  package="rGEDI")

# Unzipping GEDI level2A data
level2Apath <- unzip(level2A_fp_zip,exdir = outdir)

# Reading GEDI level2A data (h5 file)
level2a<-readLevel2A(level2Apath=level2Apath)

# Extracting GEDI Elevation and Height Metrics
level2AM = getLevel2AM(level2a)

# Specifying the path to shapefile
polygon_filepath <- system.file("extdata", "stands_cerrado.shp", package="rGEDI")

# Reading shapefile as SpatialPolygonsDataFrame object
library(raster)
polygon_spdf<-shapefile(polygon_filepath)

# Clipping GEDI data by Geometry
level2AM_clip = clipLevel2AMGeometry(level2AM, polygon_spdf, split_by="id")

hasLeaflet = require(leaflet)

if (hasLeaflet) {
leaflet() %>%
 addCircleMarkers(level2AM_clip$lat_lowestmode,
                  level2AM_clip$lon_lowestmode,
                  radius = 1,
                  opacity = 1,
                  color = "red")  %>%
 addScaleBar(options = list(imperial = FALSE)) %>%
 addPolygons(data=polygon_spdf,weight=1,col = 'white',
             opacity = 1, fillOpacity = 0) %>%
 addProviderTiles(providers$Esri.WorldImagery)
}

close(level2a)

rGEDI documentation built on Jan. 19, 2021, 3:01 p.m.