Luxembourg

Overview

Benchmark chips for Luxembourg cut from the harmonized field boundary collection for Luxembourg (edition 2026).

It contains 775 chips and 87,997 field polygons. Chips are pre-assigned to benchmark splits (train 601, val 79, test 95).

Licensed CC-BY-4.0.

Accessing the data

Browse the collection in the Portolan data browser, or read the files below straight from collection.json.

The collection ships these files alongside collection.json:

Query them with DuckDB from inside the collection directory, so the relative paths below resolve:

Schema & field notes

Columns in the chips table:

• gzd: MGRS grid zone designator of the chip's grid cell
• mgrs_10km: MGRS 100 km square plus 10 km cell identifier the chip belongs to
• id: chip identifier; matches the STAC item id (with the year suffix stripped)
• field_coverage_pct: percent of the chip's area covered by mapped field polygons
• split: which benchmark split the chip belongs to (train / val / test)
• geometry: the chip footprint, a square polygon in EPSG:4326
• bbox: bounding box of the chip footprint

FTW properties on each STAC item:

• ftw:buffer_days: half-width of the search window around the target day, in days
• ftw:buffer_expansion_size: set by the FTW pipeline; see the item JSON
• ftw:calendar_year: calendar year of the crop cycle the chip documents
• ftw:cloud_cover_chip_threshold: set by the FTW pipeline; see the item JSON
• ftw:expansions_performed: set by the FTW pipeline; see the item JSON
• ftw:field_coverage_pct: percent of the chip's area covered by mapped field polygons
• ftw:harvest_buffer_used: set by the FTW pipeline; see the item JSON
• ftw:harvest_cloud_cover: cloud cover of the selected harvest scene, in percent
• ftw:harvest_day: day of year the harvest window is centred on
• ftw:num_buffer_expansions: set by the FTW pipeline; see the item JSON
• ftw:planting_buffer_used: set by the FTW pipeline; see the item JSON
• ftw:planting_cloud_cover: cloud cover of the selected planting scene, in percent
• ftw:planting_day: day of year the planting window is centred on
• ftw:split: which benchmark split the chip belongs to (train / val / test)
• ftw:stac_host: STAC API the imagery was selected from

Label rasters available as item assets: instance_mask, semantic_2class_mask, semantic_3class_mask, decode_boundary_mask, decode_distance_mask.

Data quality & usage notes

• Field coverage is uneven: the median chip is 44.6% mapped field while the bottom 5% sit at or below 4.0%. Filter on field_coverage_pct when sparse chips would skew an evaluation.
• Masks are derived from boundaries declared for one year; later parcel changes are not reflected.
• Empty area inside a chip means unmapped, not necessarily fieldless.
• Chips on the dataset border may be only partly covered by the source boundaries.
• Imagery is chosen against a crop calendar, so acquisition dates and cloud cover vary between chips; check eo:cloud_cover on the season child items.
• Respect the pre-assigned splits: they are spatially blocked, so resampling chips at random leaks information between train and test.

Example queries

Every query below was run against this collection when this file was written; the -- result: lines are its first rows. Run them from the collection directory.

Chips per split

Chips with the highest field coverage

Field polygons intersecting one chip

Related collections

The field boundaries here come from Source field boundary collection; consult it for the original attributes, licensing terms and update cadence.