> ## Documentation Index
> Fetch the complete documentation index at: https://docs.axiomancer.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Urban Signal Grid schema

> Field reference for the Urban Signal Grid dataset — 454K H3 cells across 22 US metros scored across eight signal groups for site selection and territory intel.

The Urban Signal Grid dataset contains \~454K H3 resolution-8 cells across 22 U.S. metros. Each cell is scored across eight signal groups that measure business vitality, population momentum, economic strength, and more. Use it for site selection, territory planning, and predictive analytics.

Every record inherits the full [APRS envelope](/codex/normalization-standard) (`record_id`, `chunk_id`, bitemporal fields, `confidence_score`, `provenance`) and carries the [join keys](/codex/join-keys) documented below.

## Dataset-specific fields

| Field                  | Type             | Nullable | Description                                                                               |
| ---------------------- | ---------------- | :------: | ----------------------------------------------------------------------------------------- |
| `h3_index`             | string           |    no    | H3 resolution-8 cell (\~0.74 km²). Primary key.                                           |
| `metro_slug`           | string           |    no    | Metro area identifier.                                                                    |
| `composite_score`      | numeric \[0,100] |    no    | Weighted aggregate of all eight signal groups.                                            |
| `score_low`            | numeric          |    no    | Lower bound of the 90% confidence interval.                                               |
| `score_high`           | numeric          |    no    | Upper bound of the 90% confidence interval.                                               |
| `confidence`           | float \[0,1]     |    no    | Model confidence in the composite score.                                                  |
| `business_vitality`    | numeric \[0,100] |    no    | New business formation, closure rates, and revenue signals.                               |
| `population_momentum`  | numeric \[0,100] |    no    | Population growth trends and migration inflows.                                           |
| `demographics`         | numeric \[0,100] |    no    | Income distribution, education levels, age cohorts.                                       |
| `economic_strength`    | numeric \[0,100] |    no    | Employment density, wage levels, and sector diversity.                                    |
| `development_pipeline` | numeric \[0,100] |    no    | Active permits, construction starts, and rezoning activity.                               |
| `accessibility`        | numeric \[0,100] |    no    | Transit coverage, walkability, and commute times.                                         |
| `safety_environment`   | numeric \[0,100] |    no    | Crime rates, environmental hazard exposure, and code violations.                          |
| `amenity_demand`       | numeric \[0,100] |    no    | Retail density, restaurant activity, and consumer demand indicators.                      |
| `pioneer_flag`         | boolean          |    no    | `true` when the cell contains POIs that opened in the last 12 months in a growth context. |
| `scored_at`            | timestamptz      |    no    | Timestamp of the scoring run.                                                             |
| `scoring_version`      | string           |    no    | Methodology version (semver).                                                             |

## Signal groups

Each signal group is scored from 0 to 100 where higher values indicate stronger performance. The `composite_score` is a weighted combination of all eight groups.

| Signal group           | What it measures                                                                                      |
| ---------------------- | ----------------------------------------------------------------------------------------------------- |
| `business_vitality`    | New business formation rate, closure rate, and revenue signals from POI and licensing data            |
| `population_momentum`  | Population growth trends, net migration inflows, USPS vacancy rates, and Census ACS indicators        |
| `demographics`         | Household income distribution, educational attainment, and age-cohort diversity                       |
| `economic_strength`    | Employment density, median wage, and NAICS sector diversity from LEHD and BLS data                    |
| `development_pipeline` | Active building permits, construction starts, and recent rezoning approvals                           |
| `accessibility`        | Transit stop density, FTA NTD ridership volumes, Walk Score, and average commute time from LEHD flows |
| `safety_environment`   | Reported crime rates, environmental hazards (EPA TRI), and code violation density                     |
| `amenity_demand`       | Retail and restaurant POI density, consumer foot-traffic proxies, and review velocity                 |

<Note>
  The Urban Signal Grid is cell-based, not parcel-based. Each H3 resolution-8 cell covers approximately 0.74 km². For parcel-level analysis, join with [Permit Signals](/codex/schemas/permit-signals) or [Civic Intelligence](/codex/schemas/civic-intelligence) using `h3_index`.
</Note>

## Pioneer flag

The `pioneer_flag` field identifies cells where new points of interest opened in the last 12 months in a growth context — rising composite score, positive net migration, and nearby new construction permits. This flag helps detect early-stage neighborhood transformation before it shows up in traditional indicators.

## Join keys

| Key          | Presence | Notes                                                  |
| ------------ | :------: | ------------------------------------------------------ |
| `record_id`  |  always  | APRS URN                                               |
| `chunk_id`   |  always  | Deterministic from `record_id`                         |
| `h3_index`   |  always  | Primary spatial key — join with any H3-indexed dataset |
| `metro_slug` |  always  | Metro area identifier                                  |

## Example query

Find the top-scoring cells in a metro area and compare signal group breakdowns:

```sql theme={null}
SELECT
  h3_index,
  composite_score,
  business_vitality,
  population_momentum,
  development_pipeline,
  accessibility,
  pioneer_flag
FROM read_parquet('urban-signal-grid-2026-04.parquet')
WHERE metro_slug = 'philadelphia-pa'
  AND composite_score >= 75
ORDER BY composite_score DESC
LIMIT 20;
```

## Known limitations

* Coverage is limited to 22 U.S. metros. Cells outside covered metros are not scored.
* The grid is cell-grained (H3 resolution 8). Sub-cell variation within a \~0.74 km² area is not captured.
* `pioneer_flag` depends on POI Intelligence freshness — newly opened businesses may take up to 30 days to appear.
* Signal group weights in the `composite_score` are methodology-version-dependent. Compare scores only within the same `scoring_version`.