spanner (version 1.0.2)

download_naip_for_las: Download NAIP Imagery for LiDAR Extent

Description

Downloads NAIP (National Agriculture Imagery Program) imagery from Microsoft Planetary Computer STAC API for the extent of a LAS/LAZ point cloud.

Usage

download_naip_for_las(
  las,
  output_path = NULL,
  year_range = c("2018-01-01", "2023-12-31"),
  buffer = 0,
  overwrite = FALSE
)

Value

Character string of the output file path, or NULL if download failed.

Arguments

las

A LAS object or path to a LAS/LAZ file

output_path

Character string specifying output file path for the downloaded imagery. If NULL, creates a file named based on the input LAS file.

year_range

Character vector of length 2 specifying date range for NAIP imagery in format c("YYYY-MM-DD", "YYYY-MM-DD"). Default is c("2018-01-01", "2023-12-31").

buffer

Numeric value to buffer the extent in meters. Default is 0.

overwrite

Logical, whether to overwrite existing output file. Default is FALSE.

Details

This function queries the Microsoft Planetary Computer STAC API to find and download NAIP imagery that overlaps with the extent of the input LAS file. The imagery is automatically cropped to match the LiDAR extent and saved as a GeoTIFF.

NAIP imagery is typically 4-band (RGB + NIR) with 0.6m or 1m resolution, collected annually or biannually across the continental United States.

Requires the rstac package for STAC API access.

Examples

# \donttest{
# Load example LAS file
LASfile <- system.file("extdata", "ALS_Clip.laz", package="spanner")
las <- readLAS(LASfile)

# Download NAIP for a LAS file
naip_path <- download_naip_for_las(las, output_path = tempfile(fileext = ".tif"))

# Download with buffer and specific year range
naip_path2 <- download_naip_for_las(las, buffer = 10,
                                    output_path = tempfile(fileext = ".tif"),
                                    year_range = c("2020-01-01", "2023-12-31"))

# Then use with colorize_las
las_colored <- colorize_las(las, method = "rgb", raster_path = naip_path)
# }