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Read survey transects with their geometry

sight_read_transects.Rd

Reads the survey layout from /aerial-surveys/designs-as-points-and-lines: the designs, the points, and the lines assembled from them.

Usage

sight_read_transects(
  species = NULL,
  survey_type = NULL,
  analysis_unit = NULL,
  management_unit = NULL,
  bio_year = NULL,
  dry_run = FALSE,
  ...
)

sight_read_transects_id(
  species_id = NULL,
  survey_type_id = NULL,
  analysis_unit_id = NULL,
  management_unit_id = NULL,
  bio_year = NULL,
  dry_run = FALSE,
  ...
)

Arguments

species, survey_type

Names, resolved to ids.

analysis_unit, management_unit

Names, resolved to ids. Optional.

bio_year

Biological year.

dry_run

Return the prepared request instead of performing it.

...

Additional filters.

species_id, survey_type_id, analysis_unit_id, management_unit_id

Ids, for the _id form.

Value

A named list of three tibbles:

  • designs — the survey design rows

  • points — every point, with number, latitude, longitude

  • lines — one row per line, with left_width, right_width, stratum_id, is_surveyed, and a points list-column

Elements the response omits come back as empty tibbles rather than NULL, so a caller can index them without checking first.

Details

"Transect" covers both halves of what this returns. Distance sampling distinguishes line transects from point transects, and count-api stores both: points for point and plot designs, lines for the strips an aircraft flies.

A line is its points

location.lines holds only id, name, left_width, right_width and batch. The geometry lives on location.points, two or more rows sharing a line_id and ordered by number, each carrying a PostGIS geography(Point) that the API decodes into latitude/longitude.

So a line's shape, and its length, are derived rather than stored. spdgt.distance.admin::dist_transects_from_lines() turns the lines element of this response into the transect frame its estimation engine expects, computing length from the point coordinates.

Examples

if (FALSE) { # \dontrun{
layout <- sight_read_transects_id(
  species_id = 1L,
  survey_type_id = 3L,
  analysis_unit_id = 274L,
  bio_year = 2024L
)
nrow(layout$lines)
} # }