Clairwave

What Clairwave provides, which models/data back each tool, and limits.

Sonar detection range along a bearing from a location (lat/lon or `place`). Transmission loss (TL) is ALWAYS computed: RAM parabolic equation with the location's bathymetry, seasonal sound speed (`month`, default: current month) and seabed. Every other sonar-equation term is optional — anything not given gets a stated, typical default listed in `assumptions` with its source. Tell the user which values were assumed. Detection threshold DT is derived from processing gain (unless given): detection index d from `pd`/`pfa` (default 0.5 / 1e-4 → d ≈ 13.8), then passive (incoherent energy detector): DT = 5·log10(d / (B·T)), B = analysis band, T = `integration_time_s` (default 1 s); active (matched filter): DT = 10·log10(d / (2·B·τ)), B = `bandwidth_hz` (default 100 Hz LFM), τ = `pulse_length_s` (default 0.5 s). DT is in-band SNR, so it can be negative — that IS the processing gain. mode="passive": SE = SL − TL − (NL − DI) − DT. Default target = merchant ship (bulk carrier, AIS 70, 200 m @ 12 kn, JOMOPANS-ECHO decidecade band level) at 6 m; receiver ½ water depth (≤ 30 m), omni (DI 0 — give directivity_index_db for an array). `frequency_hz` is optional: the tool always also evaluates the target's MOST DETECTABLE 1/3-octave band in 50–2000 Hz (`best_band`) — ships are loudest there; a user frequency is reported as asked. If you give `source_level_db` without `frequency_hz`, the range is evaluated at 50 Hz. mode="active" (monostatic, `frequency_hz` required): SE = SL − 2·TL + TS − (NL − DI) − DT, TL from the sonar to the target depth. Defaults: hull sonar at 7 m, SL 220 dB, TS 10 dB (large underwater object, beam aspect), target ½ water depth (≤ 50 m), DI 20 dB (hull array). Noise-limited only: reverberation is NOT included (often the limit in shallow water). NL (unless given) = Wenz ambient noise at the CURRENT forecast wind at the point (Clairwave weather), moderate shipping, in the analysis band. Units: dB re 1 µPa (SL @ 1 m).

Seafloor depth from Clairwave-served global bathymetry (~450 m resolution). Location: lat/lon or `place` (name resolved to a water point, echoed in `location`). Without a bearing: depth at the point. With a bearing (compass degrees, 0 = north): a depth profile along that transect out to range_km.

Seasonal sound-speed profile c(z) at a location (lat/lon or `place` name, e.g. "Halifax approaches") for a calendar month (1-12), from Clairwave-served seasonal temperature/salinity climatology, plus the seabed parameters (compressional/shear speed, density ratio, attenuation, sediment type) at the same point. Cached per 0.1 degree.

Everything about one vessel: live AIS position/track and static particulars, plus its 3D model (unique photo-derived model if generated, else the class archetype) with GLB URL (bow=+Z, up=+Y) and platform links.

Photograph of a vessel from Wikimedia Commons, with attribution.

Broadband received level (dB re 1 uPa) at a fixed site — a fish farm, reef, hydrophone or marine protected area — from the ships around it, power-summed. Each vessel's source level comes from its AIS class, speed and size; transmission loss is a fast broadband model, so this is a screening estimate (use run_transmission_loss for exact site physics). hours_back = 0 uses the live snapshot; > 0 reconstructs a time series from the AIS archive in 10-minute bins (max/median/quiet levels). Location: lat/lon or `place`. Show `open_url` to the user as a clickable link.

Turn a place name ('outside Halifax', 'Strait of Hormuz', 'Bergen, Norway') into water coordinates. Maritime gazetteer first (ports resolve to their approaches, straits/seas to a representative point), then OpenStreetMap. Points on land or shallower than min_depth_m are walked seaward along the gazetteer bearing (or the nearest direction) until deep enough; the original point and the snap are reported. offshore_km pushes the point further out along seaward_bearing_deg. All location tools also accept `place` directly, so a separate call is only needed to inspect.

Full 3D transmission-loss volume around a source (lat/lon or `place`) with Bellhop (all bearings), stored on the platform under a run id. Show `open_url` to the user as a clickable link: it opens this run visualized. Returns the run id, the replication metadata (SSP, seabed, bounding box) and file links (uint8 TL cube .npy + JSON sidecar). Any frequency and radius (keep radius <= ~50 km for reasonable run times).

Run a physically grounded transmission-loss simulation (RAM parabolic equation) from a source at (lat, lon or `place`, depth) along a compass bearing. Bathymetry, the seasonal sound-speed profile (`month`) and seabed parameters are fetched for the location automatically. Returns TL vs range at the receiver depths (default: source depth, 10 m, 100 m, mid-water), grid statistics, and the full replication bundle. Show `open_url` to the user as a clickable link.

Search live AIS vessels by name or MMSI prefix (global feed).

Underwater radiated-noise source level of a ship (monopole, dB re 1 uPa m, 6 m reference source depth): decidecade spectrum (10 Hz - 100 kHz; model bands to 31.5 kHz, validated 20 Hz - 20 kHz) and broadband level, from the JOMOPANS-ECHO reference spectrum model (MacGillivray & de Jong 2021, J. Mar. Sci. Eng. 9:369), fitted to 1862 measured ship passes. Individual ships scatter about +/-6 dB rms per band. Give an MMSI (live AIS type/speed/length are used) or explicit AIS ship_type / speed / length. vessel_class overrides the AIS mapping (e.g. "vehicle_carrier", which has no AIS type). Missing speed = the class reference speed; missing length = the class mean length of the measured ships. The spectrum is usable directly as `sl_spectrum`.

Live AIS vessels within radius_km of a point (lat/lon or `place`), nearest first, with position, course/speed, type, dimensions and last-update time.