neptune-ais 0.1.0

Open AIS data platform for Python

🔱 Neptune AIS

Open AIS data platform for Python

Download, normalize, fuse, and analyze vessel tracking data from multiple open-source AIS archives.
One interface. Many sources. Clean output.

Installation • Quick Start • Data Sources • Features • CLI • Docs

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What is Neptune?

Neptune is a Python library that gives you a single, unified interface to download, normalize, and analyze AIS (Automatic Identification System) vessel tracking data from multiple open-source archives.

AIS data powers maritime domain awareness — vessel tracking, trade analytics, environmental monitoring, fishing surveillance, and port operations. But working with it is painful: every provider uses a different format, schema, delivery mechanism, and quality profile. Neptune handles all of that so you can focus on analysis.

from neptune_ais import Neptune

n = Neptune("2024-06-15", sources=["noaa"])
n.download()

positions = n.positions()          # Polars LazyFrame — normalized, QC'd
result = n.sql("SELECT mmsi, count(*) as n FROM positions GROUP BY mmsi ORDER BY n DESC LIMIT 5")

Think of Neptune as Herbie for maritime data — a clean data-access layer that handles the messy plumbing of fetching, normalizing, and cataloging data from heterogeneous archives, so you get reproducible, analysis-ready output every time.

Key Features

• Multi-source ingestion — Download from NOAA, DMA, Global Fishing Watch, Finland, AISHub, and AISStream through one API
• Automatic normalization — Every source is normalized to a canonical schema with QC scoring and provenance tracking
• Multi-source fusion — Merge overlapping sources with configurable dedup strategies (best, union, prefer:<source>)
• Polars-native — Query positions, vessels, tracks, and events as lazy DataFrames with full predicate pushdown
• SQL via DuckDB — Run SQL queries directly over your cataloged data
• Event detection — Derive port calls, EEZ crossings, vessel encounters, and loitering from raw positions
• Real-time streaming — Connect to live AIS feeds with backpressure, checkpointing, and durable sinks
• Interactive maps — Visualize positions, tracks, and events with lonboard
• Plugin system — Add custom source adapters via Python entry points
• CLI included — neptune download, neptune inventory, neptune sql, and more

Installation

Neptune's core is lightweight — only Polars, Pydantic, and httpx are required. Everything else is opt-in.

# Core (Polars + Pydantic + httpx)
pip install neptune-ais

# With SQL support (DuckDB)
pip install neptune-ais[sql]

# With spatial & visualization (GeoDataFrames, lonboard, H3)
pip install neptune-ais[geo]

# With real-time streaming (WebSocket feeds)
pip install neptune-ais[stream]

# With the CLI (Click + Rich)
pip install neptune-ais[cli]

# Everything
pip install neptune-ais[all]

Requirements: Python 3.10+

Optional dependency groups explained

Extra	Adds	Used by
sql	duckdb	Neptune.sql(), Neptune.duckdb(), DuckDBSink
parquet	pyarrow	Full Parquet write options (compression, statistics)
geo	shapely, geopandas, movingpandas, lonboard, h3	Boundary lookups, GeoDataFrame bridges, maps
stream	websockets	NeptuneStream, live AIS feeds
cli	click, rich	neptune console commands
notebooks	jupyter, ipykernel	Interactive notebook examples
dev	pytest, mypy, ruff, coverage, nbstripout	Development and testing
all	All of the above (except dev)	Full-featured install

Quick Start

Download and query AIS data

from neptune_ais import Neptune

# Download a day of NOAA AIS data
# Neptune handles: fetch → normalize → QC → partition → catalog
n = Neptune("2024-06-15", sources=["noaa"])
n.download()

# Query as a Polars LazyFrame
positions = n.positions()
df = positions.collect()
print(f"{len(df):,} position reports from {df['mmsi'].n_unique():,} vessels")

# SQL queries via DuckDB
top_vessels = n.sql("""
    SELECT mmsi, count(*) as n
    FROM positions
    GROUP BY mmsi
    ORDER BY n DESC
    LIMIT 10
""")

Common operations with helpers

from neptune_ais.helpers import latest_positions, snapshot, vessel_history

# Most recent position per vessel
latest = latest_positions(positions)

# Point-in-time snapshot — where was every vessel at noon?
noon = snapshot(positions, when="2024-06-15T12:00:00")

# Full history for a single vessel
history = vessel_history(367000001, positions=positions)

Multi-source fusion

# Combine NOAA and DMA with automatic deduplication
n = Neptune(
    ("2024-06-15", "2024-06-16"),
    sources=["noaa", "dma"],
    merge="best",       # "best" | "union" | "prefer:noaa"
)
n.download()
fused = n.positions()   # Deduplicated across sources

Event detection

# Derive maritime events from position data
events = n.events(kind="port_call", min_confidence=0.7)

# Event types: port_call, eez_crossing, encounter, loitering
# Each event includes confidence scores and full provenance

Real-time streaming

import asyncio
from neptune_ais.stream import NeptuneStream, StreamConfig
from neptune_ais.sinks import ParquetSink, promote_landing

config = StreamConfig(
    source="aisstream",
    api_key="YOUR_KEY",
    bbox=(-74.5, 40.0, -73.5, 41.0),  # New York harbor
)

async def ingest():
    sink = ParquetSink("/tmp/neptune_landing", source="aisstream")
    async with NeptuneStream(config=config) as stream:
        await stream.run_sink(sink, max_messages=10_000)
    # Promote to canonical storage
    promote_landing("/tmp/neptune_landing", store_root="~/.neptune", source="aisstream")

asyncio.run(ingest())

Data Sources

Neptune includes adapters for six open AIS data providers, with a plugin system for adding more.

Source	Provider	Coverage	Delivery	Auth	Backfill
noaa	NOAA AIS Archive	US waters, global ATON	Daily files	None	Yes
dma	Danish Maritime Authority	European waters	Daily files	None	Yes
gfw	Global Fishing Watch	Global (satellite AIS)	Daily files	API key	Yes
finland	Digitraffic Finland	Finnish waters	Epoch-based	None	Yes
aishub	AISHub	Global (variable quality)	Multiple feeds	API key	Yes
aisstream	AISStream	Global (real-time)	WebSocket	API key	No (live only)

Discover sources programmatically

from neptune_ais import sources

sources.load_all_adapters()

# List all sources
for s in sources.catalog():
    print(f"{s.source_id:<12} {s.provider:<30} auth={s.auth_scheme or 'none'}")

# Find open-data sources with backfill
for s in sources.find_sources(backfill=True, auth=False):
    print(s.source_id)

Add a custom source via plugin

External packages register adapters through Python entry points:

# In your plugin's pyproject.toml
[project.entry-points."neptune_ais.adapters"]
my_source = "my_package.adapter:MyAdapter"

Features

Architecture

Neptune is organized around a canonical dataset family and a three-layer local store:

                                ┌────────────────┐
                                │   Your Code    │
                                │  Polars / SQL  │
                                └───────┬────────┘
                                        │
                              ┌─────────▼─────────┐
                              │     Neptune API    │
                              │ .positions()       │
                              │ .tracks()          │
                              │ .events()          │
                              │ .sql()             │
                              └──┬──────────────┬──┘
                   ┌─────────────▼──┐     ┌─────▼──────────────┐
                   │  Archival Path │     │  Streaming Path    │
                   │  fetch → norm  │     │  NeptuneStream     │
                   │  → QC → store  │     │  → sink → promote  │
                   └──┬─────────────┘     └─────┬──────────────┘
       ┌──────────────▼─────────────────────────▼────────────────┐
       │                  Three-Layer Store                       │
       │  raw/ (source payloads)  →  canonical/ (normalized)     │
       │                          →  derived/ (cached products)  │
       └─────────────────────────────────────────────────────────┘
       ┌─────────────────────────────────────────────────────────┐
       │              Catalog & Manifests                         │
       │  partition tracking · schema versions · QC summaries    │
       │  staleness detection · atomic writes (stage → commit)   │
       └─────────────────────────────────────────────────────────┘

Canonical Datasets

Dataset	Description	Schema
positions	Timestamped AIS point observations (mmsi, lat, lon, sog, cog, ...)	positions/v1
vessels	Vessel identity and reference data (slowly changing dimensions)	vessels/v1
tracks	Derived trip/trajectory segments	tracks/v1
events	Maritime events (port calls, EEZ crossings, encounters, loitering)	events/v1

Quality Control

Every ingested record passes through row-level and partition-level QC checks:

• Data type validation, range checks, sentinel detection
• Confidence scoring in three tiers: HIGH (>= 0.7), MEDIUM (0.3–0.7), LOW (< 0.3)
• Per-adapter QC rule injection for source-specific quirks
• Full provenance tracking from source through fusion

Fusion Modes

When querying across multiple sources, Neptune supports three merge strategies:

Mode	Behavior
best	Deduplicate with configurable field-level precedence
union	Keep all records from all sources, tag provenance
prefer:<source>	Deterministic source preference (e.g., prefer:noaa)

Event Detection

Neptune derives four maritime event families from position data using heuristic detectors:

Event	Description
Port calls	Sustained low-speed presence within a port boundary
EEZ crossings	Transitions between exclusive economic zones
Encounters	Two vessels within 500m for a sustained duration
Loitering	Sustained low-speed movement in a small area

Each event includes a deterministic event_id, confidence score, timestamps, and full provenance linking back to source positions. See HEURISTICS.md for detection assumptions and known limitations.

CLI

Neptune includes a full command-line interface (requires pip install neptune-ais[cli]):

# Download data
neptune download --source noaa --date 2024-06-15
neptune download --source noaa --source dma --start 2024-06-01 --end 2024-06-07

# Inspect what you have
neptune inventory
neptune inventory --dataset positions

# Quality reports
neptune qc --source noaa --date 2024-06-15

# SQL queries from the terminal
neptune sql "SELECT count(*) FROM positions WHERE source = 'noaa'"

# Source catalog
neptune sources
neptune sources --compare noaa dma gfw

# Event queries
neptune events --kind port_call --date 2024-06-15

# Health and provenance
neptune health
neptune provenance --date 2024-06-15

# Promote streaming data to canonical store
neptune promote --landing-dir /tmp/neptune_landing --source aisstream

Documentation

Full Sphinx documentation is planned. In the meantime:

Resource	Description
examples/	Six narrative examples covering the full workflow
HEURISTICS.md	Event detection assumptions, confidence limits, non-goals
RELEASING.md	Release procedures and checklist
RC_CHECKLIST.md	Release-candidate validation results

Examples

#	Example	Topics
1	Source Discovery (.py)	Inspect sources, capabilities, filters
2	Archival Ingest (.py)	Download, Polars queries, SQL, helpers
3	Multi-Source Fusion (.py)	Merge strategies, fusion config
4	Event Detection (.py)	Port calls, EEZ crossings, encounters
5	Streaming Pipeline (.py)	Live feeds, sinks, promotion
6	External Plugin	Custom adapter via entry point

Tip: Install notebook support with pip install neptune-ais[notebooks] to run the interactive examples.

Contributing

Contributions are welcome. To get started:

git clone https://github.com/yourorg/neptune-ais.git
cd neptune-ais
pip install -e ".[all,dev]"
pytest

The test suite includes 768 tests covering adapter certification, schema reproducibility, streaming soak tests, and packaging validation.

License

MIT