[Medium] RStudio Cloud and rgee nightlights

medium_rstudio_cloud_rgee_nightlights.R

library(rgee)

ee_Initialize()

createTimeBand <- function(img) {
  year <- (ee$Date(img$get("system:time_start"))
               $get("year")$subtract(1991L))
  ee$Image(year)$byte()$addBands(img)
}

collection <- (ee$ImageCollection("NOAA/DMSP-OLS/NIGHTTIME_LIGHTS")
                   $select("stable_lights")
                   $map(createTimeBand))

col_reduce <- collection$reduce(ee$Reducer$linearFit())
col_reduce <- col_reduce$addBands(col_reduce$select("scale"))

ee_print(col_reduce)
Map$setCenter(9.08203, 47.39835, 3)
Map$addLayer(
  eeObject = col_reduce,
  visParams = list(
    bands = c("scale", "offset", "scale"),
    min = 0,
    max = c(0.18, 20, -0.18)
  ),
  name = "stable lights trend"
)