How units are harmonised on import
Areas to hectares, lengths to metres, dates to UTC; unclear units are excluded and recomputed from geometry.
Source layers use a mixture of units: hectares, square kilometres, square metres, degrees, percentages, local date formats. Atlas converts them as follows and records every rule in the dataset's unit map.
| Source value | Rule |
|---|---|
| Area named ha / hectares | Kept (unit taken from the field name) |
| Area named km², sq km | × 100 → hectares |
| Area named m² | × 0.0001 → hectares |
Shape_Area, Shape_Length |
Excluded: units are not stated (often degrees); area and length are recalculated from the geometry |
| Length in km | × 1,000 → metres |
| Percent fields | Kept 0–100; values outside the range are rejected and the original kept |
| Esri dates (epoch milliseconds) | Converted to ISO-8601 UTC |
| Blank text (" ") | Converted to empty |
| Coded values | Replaced by their labels, code kept |
Originals are never thrown away. The original attributes are stored in the source record and each converted number keeps its original value and unit.
Why Shape_Area is excluded. In geographic coordinates it is measured in square degrees, which is meaningless (a degree is a different distance at every latitude). Atlas computes true hectares from the shape instead.
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