phenoRice: R implementation of the phenorice model

Description Usage Arguments Details Value References Examples

Description

Run the phenorice model

Usage

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phenorice(evi, ndfi, lst, p, checkLST=TRUE)

Arguments

evi

numeric, rasterstack or SpatRaster with evi values

ndfi

numeric, rasterstack or SpatRaster with ndfi values

lst

numeric, rasterstack or SpatRaster with lst values

p

list with named parameters based on phenorice method

checkLST

boolean. If TRUE the LST is used

Details

Parameters Explanation
evi_meanth threshold for annual mean EVI
evi_maxth threshold for maximum EVI
evi_minth threshold for minimum EVI
pos_start start of heading
pos_end end of heading
vl1 shortest vegetative growth length
vl2 longest vegetative growth length
winfl period for flooding
minndfi threshold for NDFI
windecr period after EVI maximum
decr percent decrease of EVI after EVI maximum
tl1 shortest total growing length
tl2 longest total growing length
lst_th minmum land surface temperature for planting, needs checkLST=TRUE

Value

vector

References

Boschetti, M., L. Busettoa, G. Manfrona, A. Laborte, S. Asilo, S. Pazhanivelan & A Nelson, 2017. PhenoRice: A method for automatic extraction of spatio-temporal information on rice crops using satellite data time series. Remote Sensing of Environment 194: 347-365;

Busetto, L., Zwart, S.J. and Boschetti, M., 2019. Analysing spatial?temporal changes in rice cultivation practices in the Senegal River Valley using MODIS time-series and the PhenoRice algorithm. International Journal of Applied Earth Observation and Geoinformation, 75, pp.15-28.

Examples

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# Get index for one pixel
evi <- readRDS(system.file("evi.rds", package="phenorice"))
ndfi <- readRDS(system.file("ndfi.rds", package="phenorice"))
lst <- readRDS(system.file("lst.rds", package="phenorice"))

# Smooth each index
evi <- filter_VI(evi)
ndfi <- fill_VI(ndfi)
lst <- fill_VI(lst)

# Get parameters
p <- getPars()

# Run and get result (planting date, date of max EVI value, flowering date, heading date, harvest date) for tha pixel 
re <- phenorice(evi, ndfi, lst, p)

# Change parameters
p['evi_minth'] = .2
re <- phenorice(evi,ndfi,lst,p)


f <- system.file("ricevi.rds", package="phenorice")
d <- readRDS(f)
evi <- unlist(d[1,2:47])
ndfi <- unlist(d[1,48:93])
lst <- unlist(d[1,94:139])
p <- getPars()

phenorice(evi, ndfi, lst, p)


x <- matrix(NA, 25, 5)
for (i in 1:25) {
	evi <- unlist(d[i,2:47])
	ndfi <- unlist(d[i,48:93])
	lst <- unlist(d[i,94:139])
	x[i,] <- phenorice(evi, ndfi, lst, p)
}
x

cropmodels/phenorice documentation built on Nov. 19, 2019, 2:18 a.m.