Calculate canopy closure date

Usage

calc_c_closure(param_rxt, x1 = 1.3, k = 6)

Arguments

param_rxt: SpatRast, output of the function calc_r_x0, which produces a SpatRast list containing parameters that are necessary to calculate canopy closure. These parameters are r, the growth rate, x0, the initial LAI value, and t0, the initial date and the associated dates
x1: numeric, LAI value at which 90% canopy closure is reached. The default is set to 1.3 for sugar beet.
k: carrying capacity, which is the maximum LAI that can be attained. This value can be cultivar-dependent. The default is set to 6

Value

SpatRast where the values represent day where canopy closure occurred as an integer from the time origin "1970-01-01". The canopy closure date is reached when 90% canopy closure has occurred for the specified location, in this case the pixel.

Details

Calculates canopy closure dates from LAI and growth rate parameters

Examples

img_dir <- system.file("extdata", "uav_img",package = "cercospoRa")
epidemic_onset_param <-
  read_sb_growth_parameter(img_files = list.files(img_dir,pattern = "tif",
                                                  full.names = TRUE),
                           img_dates = as.POSIXct(
                             c("2022-06-14","2022-06-28"),tz = "UTC"),
                           target_res = 10)
param_rxt <- calc_r_x0(epidemic_onset_param,
                       min_r = 0.02,
                       max_r = 0.05,
                       k = 6)
canopy_closure <- calc_c_closure(param_rxt,
                                 x1 = 1.3,
                                 k=6 )