sonar
Enable an agent to recognise sonar activity, assess whether its acoustic observations support a task, and decide how it may be operated or its results used.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise sonar activity, assess whether its acoustic observations support a task, and decide how it may be operated or its results used.
Sonar is a technique, and the equipment implementing it, for detecting, locating or characterising underwater objects and environments by receiving sound, either emitted by a target or reflected from deliberately transmitted acoustic signals.
It can be Select an active or passive acquisition configuration suited to the sensing task and operating constraints.; Estimate whether propagation, noise and geometry permit a useful observation.; Acquire and associate acoustic observations with their timing, position and configuration.; Derive qualified detections, locations, tracks, classifications or maps from acoustic evidence.; Request another look, a geometry change or independent evidence when ambiguity prevents a decision.; Adjust, pause or stop operation when interference, equipment degradation or transmission constraints require it..
Distinguishing features
The sensing evidence comes from underwater acoustic signals rather than electromagnetic returns or optical images.
An active operation relates received echoes to a known transmission; a passive operation interprets sound without requiring its own sensing transmission.
A hydrophone or acoustic recording alone is insufficient to establish a sonar operation: the record must identify a detection, localisation, characterisation or mapping purpose.
Acoustic arrival direction, travel time or signal structure is interpreted through a propagation and geometry model, rather than treated as a direct observation of an object's identity.
Active sonar may support ranging from echo delay, while a passive detection must state what additional geometry or assumptions support any claimed range.
Scope
+ Active echo sensing, passive listening and configurations that combine them
+ Acoustic acquisition geometry, transmission settings and receiving arrangements
+ Water-column and boundary conditions affecting sound propagation
+ Detection, localisation, tracking, classification and seabed-mapping evidence
+ Operational readiness, acoustic interference and constraints on sound transmission
- Detailed manufacture and repair of transducers, electronics and carrier platforms
- Radar, lidar and optical underwater imaging
- Underwater acoustic communication when the purpose is message transfer rather than sensing
- Medical ultrasound and industrial ultrasonic inspection
- Weapon engagement decisions and broader navigation or survey mission management
- Marine ecosystem assessment beyond the evidence needed to constrain sonar operation
Characteristics
- Sensing mode
- active; passive; combined Determines whether transmission settings, echo timing and emitted-sound constraints apply.
- Sensing task
- detection; localisation; tracking; classification; bathymetry; acoustic imaging Defines what constitutes useful evidence and an acceptable result.
- Acoustic frequency coverage
- Hz, with transmitted and received bands recorded separately Helps assess propagation, resolution and compatibility with the intended acoustic signatures.
- Transmission pattern
- not applicable for passive-only operation; otherwise waveform, pulse duration, repetition interval and duty cycle Affects echo interpretation, interference and the pattern of acoustic exposure.
- Source level
- dB with explicit reference pressure, reference distance and level convention; not applicable for passive-only operation Supports performance and exposure assessment only when the measurement convention is known.
- Source-receiver-target geometry
- positions, depths, orientations and timing relationships, including monostatic, bistatic or multistatic arrangement where applicable Controls which localisation calculations and ambiguities apply.
- Sound-speed profile
- m/s versus depth in m, with location, timestamp and uncertainty Supports travel-time conversion and interpretation of refracted acoustic paths.
- Observation uncertainty
- range uncertainty in m; bearing uncertainty in degrees; depth uncertainty in m; confidence measures with their definitions Prevents detections and estimates from being treated as exact positions or verified identities.
- Acquisition readiness
- ready; degraded; unavailable; unverified, with calibration and fault evidence Determines whether acquisition can proceed and how existing observations should be qualified.
- Transmission permission
- permitted; conditional; prohibited; unknown for the specified place, time and configuration Separates technical ability to transmit from permission to operate.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.sonar
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Sonar task and mode Establishes which sonar activity is occurring and what its outputs must support.
Passive contact detection, active ranging and seabed mapping require different evidence and success criteria.
Acoustic sensing boundary
Identifies the intended sonar sense and separates sensing from neighbouring acoustic activities.
Sonar activity identity
Record the underwater acoustic sensing purpose and whether the referent is an operation, capability or equipment system.
- Does this instance denote a sonar operation, a sensing capability or the equipment that provides it? definition
- What makes this activity sonar sensing rather than acoustic communication or sound recording without a sensing objective? boundary
Mode and success criteria
Connects active or passive operation to the required result.
Task-specific evidence
Record the sensing mode, intended output and acceptance criteria before interpreting acquisition results.
- Does the task require detection, location, a maintained track, classification, bathymetry or an acoustic image? definition
- What coverage, uncertainty and false-alarm tolerance make the output usable for this task? measurement
Acoustic acquisition Captures the transmission, reception and geometry that produced an observation.
Sonar returns cannot be interpreted reliably without knowing how sound was emitted or received and where the participating sensors were.
Transmission and reception
Records the acoustic settings and receiver response relevant to a measurement.
Signal configuration
Record frequency coverage, waveform where applicable, receiver settings and calibration evidence sufficient to interpret recorded signals.
- Which transmitted waveform and listening band were used, or which listening band applies to passive-only acquisition? measurement
- What calibration evidence establishes the receiver response and, where relevant, transmitted level? provenance
Array geometry and timing
Connects acoustic samples to sensor locations, orientations and clocks.
Geometric observability
Record source and receiver geometry, motion and synchronisation so supported position estimates can be separated from unresolved dimensions.
- What source and receiver positions, array orientations and clock uncertainties apply during acquisition? measurement
- Which range, bearing or depth components can this geometry resolve, and which remain ambiguous? boundary
Underwater propagation Represents the acoustic environment between source, target and receiver.
Water-column structure, boundaries and competing sound can alter visibility and apparent location without a change in the target.
Water column and boundaries
Records environmental evidence used to interpret acoustic paths.
Propagation assumptions
Identify the sound-speed information, bathymetry and boundary assumptions used in travel-time and coverage interpretation.
- Which measured or assumed sound-speed profile and surface or seabed conditions support the propagation model? provenance
- How could refraction, multipath or shadowing change the inferred location or expected coverage? boundary
Noise and reverberation
Separates candidate target signals from acoustic background and distributed echoes.
Acoustic masking
Record ambient noise, platform self-noise, other transmissions and reverberation that may conceal or imitate a contact.
- What noise, interference or reverberation limits detection in the selected frequency band and observation interval? measurement
- Would changing timing, frequency, platform motion or listening geometry improve the observation? action
Sonar inference and evidence Connects acoustic measurements to qualified claims about contacts or the seabed.
A detected signal, a located reflector and an identified object are different evidential achievements.
Detection and localisation
Records how a candidate signal becomes a detection and position estimate.
Qualified contact estimate
Preserve the detection rule, arrival measurements, localisation method and uncertainty alongside each contact estimate.
- Which signal measurements and detection rule support this contact rather than noise or a propagation artefact? provenance
- For active sonar, which acoustic path converts delay into range; for passive sonar, what evidence supports any range estimate? measurement
Tracks, classifications and maps
Controls the additional inference needed to combine observations or assign meaning.
Derived product support
Record association assumptions, classification evidence or survey corrections appropriate to the derived product.
- What evidence supports associating detections into one track, assigning a target class or accepting a seabed feature? provenance
- Which alternative interpretations remain, and what additional observation would distinguish them? action
Sonar operating decisions Determines whether a sonar configuration is ready and appropriate to operate.
Useful sonar activity depends on functioning acquisition hardware, valid operating evidence and conditions governing underwater sound transmission.
Readiness and degradation
Relates sonar faults and installation conditions to sensing capability.
Usable acoustic aperture
Record failed channels, array-shape uncertainty, acoustic obstruction and installation effects that qualify readiness.
- Which checks establish that the transducers, receive channels, timing and array geometry are usable? provenance
- Does the observed degradation require a restricted task, recalibration, redeployment or suspension? action
Transmission constraints
Captures the conditions under which active sound emission may proceed.
Permitted emission envelope
Record applicable authorisations and operational constraints, including exposure-sensitive circumstances and interference with other acoustic users.
- Which authorisation or operating procedure establishes allowed locations, times, frequencies and emission settings? provenance
- What observed condition requires reducing output, delaying transmission or stopping active operation? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- The intended sense is underwater acoustic sensing and its equipment; no recorded sense establishes whether the registry means the technique or the device.
- The listed kinds overlap: active/passive distinguishes transmission behaviour, while the other terms distinguish geometry or processing.
- Frequency and sound-speed ranges are approximate recall values; verify application-specific performance and the applicable edition of IHO S-44 before operational use.
- Which of these check these first hold for the sense of sonar this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Active sonar
- Passive sonar
- Side-scan sonar
- Multibeam sonar
- Synthetic-aperture sonar
- Imaging sonar
- Which of these kinds and varieties hold for the sense of sonar this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- International Hydrographic Organization (IHO) S-44, Standards for Hydrographic Surveys, specifies survey requirements relevant to sonar-based bathymetry.
- Which of these standards and regulation hold for the sense of sonar this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Measuring water depth and mapping seabed topography.
- Locating wrecks, submerged infrastructure and other underwater objects.
- Detecting and tracking submarines or other vessels.
- Finding fish and estimating their distribution.
- Supporting underwater vehicle navigation and obstacle avoidance.
- Which of these real-world use hold for the sense of sonar this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Operating acoustic frequency - From below 1 kHz to above 1 MHz across different systems; lower frequencies generally support longer ranges and higher frequencies finer resolution. - Hz
- Sound speed in seawater used for ranging - Approximately 1450-1550 in many ocean conditions; varies with temperature, salinity and pressure. - m/s
- Active-sonar slant range - Calculated approximately as sound speed multiplied by round-trip echo delay, divided by two; achievable range depends on the system and environment. - m
- Which of these typical measurements hold for the sense of sonar this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Refraction caused by sound-speed gradients creates shadow zones and biases positions when propagation is inadequately modelled.
- Reverberation, multipath and unwanted echoes obscure targets or produce false detections.
- Ambient noise, vessel self-noise and acoustic interference reduce detection performance.
- Motion, timing, alignment or sound-speed calibration errors distort sonar imagery and bathymetry.
- High-intensity transmissions can disturb or injure marine animals and pose an exposure hazard to nearby divers.
- Which of these failure modes and hazards hold for the sense of sonar this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Local temperature, salinity, depth and ice conditions change propagation and influence sonar configuration and performance.
- Which of these regional variation hold for the sense of sonar this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- Radar - Radar uses electromagnetic waves; sonar uses acoustic waves.
- Echo sounder - An echo sounder is a specialised active sonar that measures distance, commonly water depth, from returning echoes.
- Hydrophone - A hydrophone is an underwater acoustic receiver; a sonar system combines reception with processing and, for active sonar, transmission.
- Underwater acoustic communication - Its primary purpose is transmitting information between endpoints; sonar primarily infers properties or locations of targets and surroundings.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of sonar this model covers, and on what evidence? provenance
What the second pass must settle
- Does the registry intend sonar as an activity, a technology or an equipment class, and what explains its ACT / ACT.ACT placement?
- Does an existing world model already own sonar or underwater acoustic sensing, requiring this entry to link to it?
- Which sonar families need explicit specialisation within this entry, particularly passive arrays, side-scan, multibeam and synthetic-aperture sonar?
- Which authoritative conventions should govern acoustic level reporting, calibration, detection confidence and uncertainty for the intended applications?
- Which jurisdictions, environments and operating organisations determine the transmission constraints this model must be able to record?