nimbus

The goal of nimbus is to simulate cloud cover and add it to raster files.

Installation

You can install the development version of nimbus from GitHub with:

# install.packages("devtools")
devtools::install_github("jonotuke/nimbus")

Example

First we load the package.

library(nimbus)
library(raster)
#> Loading required package: sp
## basic example code

We will illustrate by adding a cloud cover to the example raster. First we look at the example raster

plot(example_raster)

We will simulate a 70 × 70 pixels cloud

cloud <- simulate_cloud(phi = 0.1, seed = 2023)

plot(cloud)

Next, we will match the extent and projection of the simulated cloud raster with the original raster.

cloud <- match_rasters(example_raster, cloud)
plot(cloud)

cloud
#> class      : RasterLayer 
#> dimensions : 7061, 7911, 55859571  (nrow, ncol, ncell)
#> resolution : 30, 30  (x, y)
#> extent     : 426885, 664215, 7019185, 7231015  (xmin, xmax, ymin, ymax)
#> crs        : +proj=utm +zone=55 +south +datum=WGS84 +units=m +no_defs 
#> source     : memory
#> names      : Z 
#> values     : -5.199408, 5.321076  (min, max)

Now, we will filter the cloud and convert values to NAs that will add ask masks in the next stage.

speckled_cloud <- filter_cloud(cloud)
large_cloud <- filter_cloud(cloud, type = "large")

plot(speckled_cloud)

plot(large_cloud)

Finally, we can now add the clouds to the original raster

example_raster |> add_cloud(speckled_cloud) |> plot()

example_raster |> add_cloud(large_cloud) |> plot()