---
title: "Spatial density grid"
method: GET
path: "/api/v2/maritime/density"
tags: ["Maritime"]
---

# Spatial density grid

`GET /api/v2/maritime/density`

Spatial density grid (heatmap) of position and vessel counts per lat/lon cell within an area. Shows where traffic concentrates. AREA REQUIRED — pass bbox, near, or near_gem_id. Requires a plan with Maritime intelligence access (`can_use_maritime`) — the Corporate & Supply Chain plan and above.

Historical / baseline surface: reads raw AIS positions directly. Forward-accruing: positions begin at launch (June 2026) — no historical backfill. Terrestrial AIS only (no satellite). Date windows are capped at 7 days; defaults to the trailing 1 day.

## Query parameters

- `bbox` string
- `near` string
- `near_gem_id` string
- `radius_km` number
- `cell_deg` number
- `date_start` string
- `date_end` string
- `days` integer
- `limit` integer

## Response `200`

Density grid, densest cells first. Envelope: { success, cell_deg, data, pagination, applied_filters }. Each data row: cell_lat, cell_lon (cell SW/lower corner, degrees), positions (AIS message count), vessels (distinct mmsi).

- object
  - `success` boolean
  - `cell_deg` number
  - `data` object[]
    - `cell_lat` number
    - `cell_lon` number
    - `positions` integer
    - `vessels` integer
  - `pagination` object
    - `limit` integer
    - `cursor` unknown
    - `next_cursor` unknown
  - `applied_filters` object
    - `date_start` string
    - `date_end` string
    - `cell_deg` number
    - `bbox` string
    - `ignored` object

## Other responses

- `400` — Area required or invalid parameter (AREA_REQUIRED, INVALID_BBOX, INVALID_NEAR, INVALID_RADIUS)
- `401` — Missing/invalid API key
- `403` — Plan required (PLAN_REQUIRED) — the caller's plan does not carry the required source entitlement.
- `500` — Server error

---

[API](https://skmtc.net/gdeltcloud/apis/gdelt-cloud-api-v2.md) · [All operations](https://skmtc.net/gdeltcloud/apis/gdelt-cloud-api-v2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/gdeltcloud/gdelt-cloud-api-v2/revisions/01aaa6255180/schema)