Scalar Document

Purpose

Represents a single numeric measurement or a small set of key/value metrics at a location or over an area (e.g., coherence mean, water level, area statistics).

GeoJSON (DB metadata)

{
  "type": "Feature",
  "geometry": {"type": "Point", "coordinates": [30.15, 59.95]},
  "properties": {
    "type": "Scalar",
    "title": "Mean Coherence",
    "created_at": "2025-09-02T12:00:00Z",
    "updated_at": "2025-09-02T12:00:00Z",
    "source": {
      "url": "/tiler/tiles/{z}/{x}/{y}@2x",
      "type": "Raster",
      "max_zoom": 16,
      "tileSize": 512,
      "url_params": {
        "url": "s3://<bucket>/<ResultKey>/<filename>"
      }
    },
    "values": {
      "coh_mean": 0.62,
      "coh_std": 0.12
    },
    "legend": {"title": "Coherence"},
    "metadata": {"window": "3x3", "sensor": "S1A"}
  }
}

Required properties

properties.type = Scalar
properties.source.url and properties.source.type
Either properties.values with inline scalars or an external JSON/CSV pointed by properties.source.url

Publishing workflow

Produce metric values (JSON/CSV).
Upload payload to storage and record its URL.
Create a GeoJSON Feature with type Scalar and link via properties.source.url.
Insert/update the Feature row in the features table.

Validation checklist

Coordinates are valid (WGS84) and geometry type matches use case.
Values are numeric and units are documented in metadata.
properties.source.type matches the data kind.

See Common properties for shared fields like legend, metadata, and classification.

Alternate (DB-aligned) Scalar as single-band raster index

In production OCLI, many Scalar layers are delivered as single-band rasters with bands/band_meta and a tiler-backed source.

Example:

{
  "type": "Feature",
  "geometry": {"type": "Polygon", "coordinates": [[[-7.5455984, 37.2931467], [-7.5487709, 37.1277062], [-7.2748512, 37.1240356], [-7.2710805, 37.2894542], [-7.5455984, 37.2931467]]]},
  "properties": {
    "type": "Scalar",
    "roles": ["demo_read", "draft_read"],
    "Bucket": "staging",
    "source": {
      "url": "/tiler/tiles/{z}/{x}/{y}@2x",
      "type": "Raster",
      "max_zoom": 20,
      "tileSize": 512,
      "url_params": {
        "url": "s3://<bucket>/<ResultKey>/<filename>"
      }
    },
    "version": 1.4,
    "Endpoint": "http://rook-ceph-rgw-geo.rook-ceph.svc:80",
    "ResultKey": "marine/faro_capella_index/faro_capella/ext_index_09gec",
    "friendly_name": "Faro/Capella/C09_GEC",
    "bands": {
      "band_ids": ["Band_0"],
      "band_meta": [
        {"band": 1, 
          "name": "Band_0", 
          "type": "UInt16", 
          "min": 1.0, 
          "max": 65535.0, 
          "domain_min": 1.0, 
          "domain_max": 65535.0, 
          "color_map": {"name": "transform_space", "type": "preset"}}
      ]
    },
    "classification": {"ocli": [5], "metadata_preset": [6]}
  }
}

See Common properties for shared fields like legend, metadata, and classification. See also: GeoJSON Strategy and Upload Strategy.