Skip to contents

Check for tiles with multi-temporal coverage in LASfiles

Source: R/is_multitemporal.R
is_multitemporal.Rd

Analyzes tiles for multi-temporal coverage. Returns a data frame with tile information including whether each tile has multiple observations and how many.

Usage

is_multitemporal(
  path,
  entire_tiles = TRUE,
  tolerance = 1,
  full.names = FALSE,
  multitemporal_only = FALSE
)

Arguments

path

Character. Path to a LAS/LAZ/COPC file, a directory containing LASfiles, or a Virtual Point Cloud (.vpc) referencing LASfiles.

entire_tiles

Logical. If TRUE, only considers tiles that are exactly 1000x1000 m and aligned to a 1000m grid (default: TRUE)

tolerance

Numeric. Tolerance in coordinate units for snapping extents to grid (default: 1, submeter inaccuaries are ignored). If > 0, coordinates within this distance of a grid line will be snapped before processing. Set to 0 to disable snapping.

full.names

Logical. Whether to return full file paths (default: FALSE)

multitemporal_only

Logical. If TRUE, only returns tiles with multiple observations (default: FALSE)

Value

A data.frame with columns:

filename

Name or path of the file

tile

Tile identifier (xmin_ymin in km)

date

Date of observation

multitemporal

Logical indicating if tile has multiple observations

observations

Number of observations for this tile

Details

This function identifies tiles that have been observed multiple times (multi-temporal coverage). It reads extent and date information from a VPC (Virtual Point Cloud) file, optionally snaps coordinates to a regular grid, and groups observations by spatial extent.

When entire_tiles = TRUE, only tiles that are 1000x1000 m and aligned to a 1000 m grid are included in the analysis.

When tolerance > 0, coordinates within that distance of a grid line are snapped to handle minor inaccuracies.

See also

filter_multitemporal

Examples

folder <- system.file("extdata", package = "managelidar")
las_files <- list.files(folder, full.names = T, pattern = "*.laz")

las_files |> is_multitemporal(tolerance = 10)
#> Error in loadNamespace(x): there is no package called ‘lasR’