Calculate comprehensive vegetation indices

Calculate a wide range of vegetation indices from spectral bands with automatic band detection, comprehensive error handling, and validation. Supports 40+ different vegetation indices for various applications. Accepts directories, file lists, and automatic CRS handling.

Usage

calculate_vegetation_index(
  spectral_data = NULL,
  red = NULL,
  nir = NULL,
  blue = NULL,
  green = NULL,
  swir1 = NULL,
  swir2 = NULL,
  red_edge = NULL,
  coastal = NULL,
  nir2 = NULL,
  index_type = "NDVI",
  auto_detect_bands = FALSE,
  band_names = NULL,
  clamp_range = NULL,
  mask_invalid = TRUE,
  scale_factor = 1,
  auto_crs_fix = TRUE,
  region_boundary = NULL,
  verbose = FALSE
)

Arguments

spectral_data

Either individual bands (red, nir, etc.), a multi-band raster, directory path, or list of raster files

red

Red band SpatRaster or file path

nir

NIR band SpatRaster or file path

blue

Optional blue band

green

Optional green band

swir1

Optional SWIR1 band

swir2

Optional SWIR2 band

red_edge

Optional Red Edge band

coastal

Optional Coastal/Aerosol band

nir2

Optional second NIR band

index_type

Vegetation index to calculate (see list_vegetation_indices())

auto_detect_bands

Automatically detect bands from multi-band raster

band_names

Custom band names for multi-band input

clamp_range

Range to clamp output values (optional)

mask_invalid

Mask invalid/extreme values

scale_factor

Scaling factor if needed (default: 1)

auto_crs_fix

Automatically fix CRS mismatches between bands

region_boundary

Optional boundary to crop and mask the result. Can be an sf object, file path to shapefile, or region name (if get_region_boundary() is available)

verbose

Print progress messages

Value

SpatRaster of vegetation index

Details

Input Format Support:

Single Calculation:

# Individual band files
ndvi <- calculate_vegetation_index(red = "red.tif", nir = "nir.tif", index_type = "NDVI")

# Multi-band raster
evi <- calculate_vegetation_index(spectral_data = "landsat.tif", index_type = "EVI",
                                 auto_detect_bands = TRUE)

Directory/Multiple Files:

# Directory with band files
savi <- calculate_vegetation_index(spectral_data = "/path/to/bands/",
                                  band_names = c("red", "nir"), index_type = "SAVI")

# File list
arvi <- calculate_vegetation_index(spectral_data = c("red.tif", "nir.tif", "blue.tif"),
                                  index_type = "ARVI")

Enhanced vs Basic NDVI:

Basic calculate_vegetation_index():

• Single time point calculation

• 40+ different indices

• Directory/file support

• Automatic CRS fixing

• Use for: Single-date analysis, comparing different indices

calculate_ndvi_enhanced():

• Time series support

• Quality filtering

• Temporal smoothing

• Date matching between red/NIR

• Use for: Multi-temporal analysis, time series trends

#' ## Band Naming Conventions:

The function supports case-insensitive band detection:

• Generic names: "red"/"RED"/"Red", "nir"/"NIR", "blue"/"BLUE", "green"/"GREEN"

• Landsat 8/9: B1-B7 (e.g., B4=Red, B5=NIR)

• Sentinel-2: B01-B12 (e.g., B04=Red, B08=NIR, B05=RedEdge)

• MODIS: band1-band7

Satellite-Specific Examples:

Landsat 8/9:

# Bands automatically detected
ndvi <- calculate_vegetation_index(
  spectral_data = "LC08_stack.tif",  # Has bands named B1-B7
  index_type = "NDVI",
  auto_detect_bands = TRUE
)

Sentinel-2:

# Red Edge indices need Sentinel-2
ndre <- calculate_vegetation_index(
  spectral_data = sentinel_data,  # Has B01-B12
  index_type = "NDRE",
  auto_detect_bands = TRUE
)

Custom band names:

# Rename your bands first
names(my_raster) <- c("red", "nir", "blue", "green")

# Or specify explicitly
ndvi <- calculate_vegetation_index(
  red = my_raster[[1]],
  nir = my_raster[[4]],
  index_type = "NDVI"
)

For complete band naming documentation, see: vignette("vegetation-indices", package = "geospatialsuite")

Examples

if (FALSE) { # \dontrun{
# These examples require satellite imagery files (Landsat/Sentinel data etc.)
# Basic NDVI calculation
ndvi <- calculate_vegetation_index(red = red_band, nir = nir_band, index_type = "NDVI")

# Multi-band raster with auto-detection
evi <- calculate_vegetation_index(spectral_data = landsat_stack,
                                 index_type = "EVI", auto_detect_bands = TRUE)

# Directory with automatic band detection
savi <- calculate_vegetation_index(spectral_data = "/path/to/sentinel/bands/",
                                  index_type = "SAVI", auto_detect_bands = TRUE)

# Advanced index with custom parameters
pri <- calculate_vegetation_index(red = red_band, nir = nir_band, green = green_band,
                                 index_type = "PRI", clamp_range = c(-1, 1))

# Custom band names for multi-band data
ndvi <- calculate_vegetation_index(spectral_data = sentinel_data,
                                  band_names = c("B4", "B3", "B2", "B8"),
                                  index_type = "NDVI")

# With region boundary (auto CRS conversion and crop/mask)
ndvi_ohio <- calculate_vegetation_index(red = red_band, nir = nir_band,
                                       index_type = "NDVI",
                                       region_boundary = boundary_sf,
                                       verbose = TRUE)
} # }