lsat_summarize_growing_seasons: Summarize growing season characteristics using spectral...

In logan-berner/lsatTS: An R package to facilitate retrieval, cleaning, cross-calibration, and phenological modeling of Landsat time-series data

Summarize growing season characteristics using spectral vegetation indices

Description

This function not only computes mean, median, and 90th percentile of a spectral index (SI) using observations for a user-specified "growing season," but also estimates the annual maximum SI and associated day of year using phenology modeling and growing season observations.

Usage

lsat_summarize_growing_seasons(dt, si, min.frac.of.max = 0.75)

Arguments

dt	Data.table generated by the function lsat_fit_phenological_curves().
si	Character string specifying the spectral vegetation index to summarize (e.g., NDVI).
min.frac.of.max	Numeric threshold (0-1) that defines the "growing season" as the seasonal window when the phenological curves indicate the SI is within a specified fraction of the maximum SI. In other words, an observation is considered to be from the "growing season" when the SI is within a user-specified fraction of the curve-fit growing season maximum SI.

Value

Data.table summarizing annual growing season conditions based on a spectral index.

Examples

data(lsat.example.dt)
lsat.dt <- lsat_format_data(lsat.example.dt)
lsat.dt <- lsat_clean_data(lsat.dt)
lsat.dt <- lsat_calc_spectral_index(lsat.dt, 'ndvi')
# lsat.dt <- lsat_calibrate_rf(lsat.dt, band.or.si = 'ndvi', write.output = F)
lsat.pheno.dt <- lsat_fit_phenological_curves(lsat.dt, si = 'ndvi') 
lsat.gs.dt <- lsat_summarize_growing_seasons(lsat.pheno.dt, si = 'ndvi')
lsat.gs.dt

logan-berner/lsatTS documentation built on Oct. 21, 2024, 12:23 a.m.