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Seafloor depth at each sample position from a GEBCO GeoTIFF

Source: R/depth.R
sample_seafloor.Rd

Extracts, for every distinct position in sample_tbl, the bilinear seafloor depth (positive down, land clamped to 0 — the same convention as calcofi4r::cc_bathy_depth()) and the deepest cell in the 3x3 neighbourhood around it, which is what a plausibility check should compare against: on a slope the neighbourhood is deeper than the cell, and by the amount the slope warrants.

Usage

sample_seafloor(
  con,
  gebco_tif,
  sample_tbl = "sample",
  key_col = "sample_key",
  lon_col = "longitude",
  lat_col = "latitude"
)

Arguments

con

DBI connection holding sample_tbl.

gebco_tif

Path to a GEBCO GeoTIFF (elevation, metres, negative below sea level). Any extent works; positions outside it return NA. A /vsicurl/... (or http(s)://) source streams over GDAL's range reads — the release's fallback when no local tile is present (D29).

sample_tbl, key_col, lon_col, lat_col

Table and columns to read.

Value

A data.frame: <key_col>, seafloor_depth_m, seafloor_max3x3_m.