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Audit Basemap Imagery Vintage and Sensor Quality Across Survey Areas

Source: R/vantor_fieldwork.R
vantor_vintage_report.Rd

Evaluates the acquisition dates (acq_time), ground sample distance (gsd), off-nadir angle (ona), and contributing satellite sensors across an Area of Interest or a set of Enumeration Area / survey grid polygons. Can either query the Vantor OGC WFS Seamlines endpoint via vantor_get_seamlines() or use a pre-fetched seamlines sf object for offline workflows.

Usage

vantor_vintage_report(
  aoi,
  seamlines = NULL,
  product = "VIVID_STANDARD_30",
  max_age_days = 730,
  reference_date = Sys.Date(),
  token = NULL,
  api_key = NULL,
  verbose = getOption("vantorr.verbose", TRUE)
)

Arguments

aoi

An sf object (such as Enumeration Areas or the output of vantor_survey_grid()), or any spatial bounding box supported by vantor_as_bbox().

seamlines

Optional sf object of seamline polygons previously fetched via vantor_get_seamlines(). If NULL, fetched automatically from the Vantor WFS API.

product

Character string. Vivid product name when fetching seamlines. Default is "VIVID_STANDARD_30".

max_age_days

Numeric. Threshold in days beyond which imagery is flagged with vintage_warning = TRUE. Default is 730 (2 years).

reference_date

Date or character string ("YYYY-MM-DD") used to calculate age_days. Defaults to Sys.Date().

token

Character string. Optional OAuth2 bearer token.

api_key

Character string. Optional Vantor/Maxar API key.

verbose

Logical. Print summary messages. Default is getOption("vantorr.verbose", TRUE).

Value

An sf object representing aoi enriched with vintage audit columns:

  • n_strips: Number of intersecting satellite mosaic strips

  • earliest_acq_date, latest_acq_date: Earliest and latest strip acquisition dates (YYYY-MM-DD)

  • max_age_days: Age in days of the oldest intersecting imagery strip relative to reference_date

  • min_gsd_m, max_gsd_m: Minimum and maximum ground sample distance (meters)

  • max_ona_deg: Maximum off-nadir angle (degrees)

  • sensors: Comma-separated list of contributing satellite sensors

  • vintage_warning: Logical TRUE if max_age_days > max_age_days threshold

Examples

# Offline example using synthetic seamlines and a survey grid
aoi <- sf::st_bbox(
  c(xmin = -105.01, ymin = 39.73, xmax = -105.00, ymax = 39.74),
  crs = sf::st_crs(4326)
)
grid_sf <- vantor_survey_grid(aoi, cell_size = 600, verbose = FALSE)

mock_seamline <- sf::st_sf(
  acq_time = "2024-05-10T18:00:00Z",
  gsd = 0.30,
  ona = 11.5,
  sensor = "WV03",
  catid = "1040010012345600",
  geometry = sf::st_as_sfc(aoi)
)

audit_sf <- vantor_vintage_report(
  aoi = grid_sf,
  seamlines = mock_seamline,
  verbose = FALSE
)