Tables of cell stats
Terra has 15 resolution levels (Res 0–14). Resolution 0 is coarsest (~57,648 km² per cell). Resolution 14 is finest (~0.09 m² per cell).
Resolution 8 is the national base standard — each cell covers exactly 1 hectare (10,000 m²).
The hierarchy uses aperture-7: each level finer divides area by 7 and edge length by √7 ≈ 2.646.
Cell statistics
| Res | Name | Avg cell area | Cell edge | KSA cells (approx) | Primary use |
|---|---|---|---|---|---|
| 0 | National | ~57,648 km² | ~149 km | ~37 | Country tile |
| 1 | Macro | ~8,235 km² | ~56 km | ~261 | Large region |
| 2 | Region | ~1,176 km² | ~21 km | ~1,828 | Admin region |
| 3 | Province | ~168 km² | ~8 km | ~12,800 | Province / Mintaqah |
| 4 | Sector | ~24 km² | ~3 km | ~89,600 | Governorate |
| 5 | District | ~3.43 km² | ~1.15 km | ~627,000 | Municipal district |
| 6 | Zone | ~49 ha | ~434 m | ~4.4 M | Urban zone |
| 7 | Block | ~7 ha | ~164 m | ~30.7 M | City block |
| 8 ★ | Cell | 1.00 ha | ~62 m | ~215 M | National base standard |
| 9 | Sub-cell | ~1,429 m² | ~23 m | ~1.5 B | Building footprint |
| 10 | Micro | ~204 m² | ~8.9 m | ~10.5 B | Room / vehicle |
| 11 | Nano | ~29 m² | ~3.3 m | ~73.5 B | Doorstep / asset |
| 12 | Pico | ~4.2 m² | ~1.3 m | ~514 B | Precise position |
| 13 | Survey | ~0.6 m² | ~0.48 m | ~3.6 T | Sub-metre survey (≈ 0.5 m) |
| 14 | Precision | ~0.09 m² | ~0.18 m | ~25 T | Centimetre accuracy |
★ All Terra functions default to res=8 when no resolution is specified.
Notes
Equal-area projection — Terra uses Lambert Azimuthal Equal Area (LAEA) centred on Saudi Arabia (24°N, 45°E). Every cell at a given resolution has the same area everywhere in the Kingdom — no distortion across the territory.
SANSRS datum — Cell areas and edge lengths are computed on the GRS 1980 ellipsoid using the KSA-GRF17 datum (EPSG:9333), as mandated by SANSRS.
Choosing a resolution — Work from the size of the thing you are indexing, not from the precision of your GPS fix. A delivery address, a parcel, or a utility connection point sits naturally at Res 8. A building footprint wants Res 9. Anything finer than Res 11 is a survey instrument's domain, and storing it implies you can defend that accuracy.
Storage — Resolution is carried inside the 64-bit index, so a mixed-resolution set of cells costs no more to store than a uniform one. There is no need to normalise a dataset to a single resolution before indexing it.
The Terra System is designed and developed by Tec Solution KSA.