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Generate Li Nighttime Light

Source: R/data_linight.R
gen_linight_mean.Rd

Aggregates the high-resolution Li et al. harmonized global nighttime lights dataset to PRIO-GRID resolution for all available years (1992–2021). This produces PRIO-GRID cell-level averages of nighttime light intensity, harmonized with PRIO-GRID’s spatial and temporal structure.

Usage

gen_linight_mean()

Value

A SpatRaster object

Details

The function:

  • Reads annual nighttime lights rasters via read_linight

  • Aggregates 1 km nighttime light intensity values into PRIO-GRID cells using mean values

  • Retains global temporal coverage (1992–2021) as a multi-layer SpatRaster

  • Aligns precisely to PRIO-GRID spatial extent (resampling handled in read_linight)

Note

  • Aggregation uses mean values to represent typical nighttime light intensity per PRIO-GRID cell

  • For sum-based aggregation (e.g., total light output per cell), see robust_transformation with agg_fun = "sum"

  • Large rasters may take time and memory to process

References

Li X, Zhou Y, Zhao M, Zhao X (2020). “A Harmonized Global Nighttime Light Dataset 1992–2018.” Scientific Data, 7(1), 168. ISSN 2052-4463, doi:10.1038/s41597-020-0510-y , https://www.nature.com/articles/s41597-020-0510-y.

Examples

if (FALSE) { # \dontrun{
# Generate PRIO-GRID level Li Nighttime Lights data
linight_pg <- gen_linight_mean()

# Inspect structure
print(linight_pg)

# Plot mean nighttime lights for 2000
terra::plot(linight_pg[["2000-01-01"]],
            main = "PRIO-GRID Nighttime Lights (Mean, 2000)")

# Compare mean intensity change between 2000 and 2020
lights_2000 <- linight_pg[["2000-01-01"]]
lights_2020 <- linight_pg[["2020-01-01"]]
change <- lights_2020 - lights_2000
terra::plot(change, main = "Change in Mean Nighttime Lights 2000–2020")
} # }