compass
Enable an agent to recognise a navigational compass, assess whether its directional indication is trustworthy, and determine how it can be used in its present conditions.
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 a navigational compass, assess whether its directional indication is trustworthy, and determine how it can be used in its present conditions.
A compass is a navigational instrument that indicates a reference direction, usually magnetic north or true north, so that headings and bearings can be determined.
It can be Identify the compass's directional reference and interpret its indication.; Orient a map or establish a direction using a compatible reference convention.; Take or transfer a bearing using the available alignment and sighting features.; Check readings against an independent directional reference or repeatable test.; Configure supported reference corrections or perform documented calibration and compensation.; Recognise conditions requiring relocation, servicing or suspension of directional use..
Distinguishing features
Provides a directional reference or heading indication; a drawing compass instead establishes a radius or transfers a distance.
Supports orientation without requiring translational travel; a device reporting only course over ground does not thereby qualify as a compass.
Relates its indication to an identifiable directional reference; an angle scale or sighting device alone does not establish that reference.
Converts its sensing or reference mechanism into usable direction information; raw magnetic-field measurements alone are insufficient.
Scope
+ Direction-sensing or direction-maintaining principle and any power dependency
+ North reference, heading indication and bearing-reading features
+ Compass-specific alignment, levelling, mounting and environmental constraints
+ Directional error, calibration, compensation and verification
+ Readiness, condition and maintenance of compass components
- Drawing compasses used to construct circles or transfer distances
- Maps, charts, routes and navigation plans
- Complete navigation systems that incorporate a compass
- Standalone magnetometers without a directional indication function
- Product-line catalogues and individual-unit asset histories
Characteristics
- Operating principle
- Magnetic needle or card; electronic magnetic sensing; other principle pending scope verification Determines dependencies, likely errors and appropriate verification methods.
- Directional reference
- Magnetic north; true north; grid north; configurable; unknown A bearing is ambiguous unless its reference is known.
- Indicated direction
- Degrees or explicitly identified angular convention, with reference and observation conditions Makes the reading interpretable without assuming that every scale uses the same convention.
- Scale or display resolution
- Degrees per graduation or display increment Limits how finely a reading can be recorded without implying equivalent accuracy.
- Directional accuracy evidence
- Angular error in degrees, with test conditions, reference method and evidence source Supports a judgement about suitability for the intended directional task.
- Bearing acquisition method
- Direct dial reading; baseplate alignment; mirror sighting; prism sighting; electronic display or output Determines what alignment and observation actions produce a meaningful bearing.
- Installation alignment
- Relationship between the compass index or sensing axis and the host's forward axis or chosen baseline Separates a correct instrument reading from an incorrectly installed heading indication.
- Permitted operating attitude
- Tilt limits in degrees and any levelling or gimbal requirements, when documented Helps determine whether the sensing element can operate correctly in the current orientation.
- North-reference correction
- Unset; mechanically adjusted; electronically configured; applied externally; unknown, with signed angle and convention Prevents omission or double application of a reference conversion.
- Magnetic balance applicability
- Documented geographic balance zone; global balance; not applicable; unknown Flags whether geographic magnetic inclination may affect a magnetic compass's operation.
- Local magnetic influence
- Assessed acceptable; suspected interference; measured deviation; unassessed Nearby magnetic materials or electrical equipment can undermine a magnetic indication.
- Directional readiness
- Ready; settling; calibration required; obstructed or sticking; power unavailable; failed; unknown Determines whether to take a reading, perform a check or suspend use.
Also called
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.compass-artifact
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 15 findings · 27 questions.
Directional identity Establishes what qualifies as this compass and how it obtains its directional reference.
The name is ambiguous, and different compass principles cannot share unqualified assumptions about magnetic north or power.
Navigational sense
Defines the compass boundary against drawing instruments and neighbouring navigation devices.
Direction reference function
Record the direction-indicating function that establishes membership in this kind.
- Does this instrument establish a directional reference, rather than merely draw circles, measure relative angles or report movement direction? boundary
- Does the registry entry cover all navigational compass principles or specifically magnetic compasses? definition
Reference generation
Connects the sensing principle to the reference and dependencies it requires.
Principle and dependencies
Record how direction is obtained and what must be available before the indication becomes usable.
- What physical sensing or reference-maintaining principle produces the direction indication? definition
- What power, initialization, settling or external inputs does that principle require before a reading is valid? action
Bearing interpretation Makes compass readings reproducible and compatible with the directional reference used by the task.
A displayed angle can be misused if its index, scale, reference or applied correction is unclear.
Reading geometry
Identifies the scale, index and sighting alignment that define a reading.
Bearing acquisition
Record how an observer or connected system obtains the intended heading or target bearing.
- Which index, lubber line, sight line or sensing axis defines the direction being read? definition
- What angular convention and graduation or display increment apply, and how must the compass be aligned to take the reading? measurement
Reference conversion
Separates the native directional reference from any correction used in the task.
North reference accounting
Record the reference of the output and where conversions between magnetic, true or grid directions occur.
- Which north reference does the current indication represent, and which reference does the map, chart or receiving system require? definition
- What correction is applied, with what sign convention, and is it applied inside the compass or during interpretation? action
- What source, location and date support any geographic magnetic-declination value used? provenance
Operating context Describes the placement and surrounding conditions needed for a credible directional indication.
Compass reliability depends on orientation, installation and, for magnetic instruments, the local magnetic environment.
Attitude and installation
Captures levelling, mounting and geographic balance constraints.
Usable orientation
Record the relationship between permitted compass attitude, host alignment and geographic applicability.
- What tilt, levelling, gimbal or host-axis alignment requirements govern use? measurement
- For a magnetic needle or card, what documented balance-zone or global-balance limitations apply at the intended location? boundary
Magnetic surroundings
Addresses nearby sources of magnetic influence and changes in the installation environment.
Interference and deviation
Record evidence of local magnetic disturbance separately from geographic declination.
- Does the indicated direction change when nearby equipment is powered, magnetic objects are moved or the compass is relocated? measurement
- What documented separation, relocation or installation-compensation procedure is appropriate when interference is suspected? action
- For a mounted magnetic compass, what evidence supports any heading-dependent deviation correction? provenance
Directional trust and care Connects verification results and component condition to decisions about continued use.
A compass can present a readable but unreliable indication, so apparent operation alone cannot establish readiness.
Performance verification
Separates reading resolution from demonstrated directional accuracy and repeatability.
Verified directional performance
Record directional error and repeatability against an appropriate independent reference.
- What angular error and repeatability were observed across relevant headings and operating attitudes? measurement
- What independent reference and test procedure support those results? provenance
- What documented acceptance criterion determines whether the compass is suitable for its intended task? action
Condition and recovery
Identifies compass-specific defects and supported routes back to service.
Readiness and service
Record defects affecting free movement, damping, readability, sensing or configuration, and the evidence needed to resume use.
- Are there signs of sticking, unstable settling, capsule leakage, obstructed sighting, unreadable markings or electronic calibration faults? measurement
- Which observed conditions require a documented adjustment, calibration, component replacement or withdrawal from use? action
- What verification must follow servicing, impact, remounting or a material change in nearby equipment? 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 registry records no sense; this description assumes the navigational instrument rather than the drawing tool.
- Passive magnetic compasses require no external power; fluxgate, gyrocompass and satellite implementations generally do.
- Accuracy, dimensions, maintenance requirements and applicable standards depend on compass type and intended service; none are asserted here.
- Which of these check these first hold for the sense of compass this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Magnetic needle compass
- Marine magnetic card compass
- Fluxgate compass
- Gyrocompass
- Satellite compass
- Which of these kinds and varieties hold for the sense of compass this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Orienting maps and following bearings during land navigation
- Indicating vessel heading during marine navigation
- Providing aircraft heading information
- Measuring approximate directions during field surveys
- Supplying heading information to navigation and control systems
- Which of these real-world use hold for the sense of compass this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Heading or bearing expressed as azimuth - 0 to less than 360 - degree
- Which of these typical measurements hold for the sense of compass 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.
- Nearby magnets, electrical currents and ferrous objects can deflect magnetic compasses.
- Confusing magnetic north with true north introduces an error equal to the uncorrected local magnetic declination.
- A damaged pivot, sticking needle or faulty liquid damping can delay or prevent a reliable magnetic reading.
- Excessive tilt and magnetic dip can impair a magnetic compass, particularly outside its intended operating region.
- Powered compasses can lose heading output through power failure; satellite compasses also depend on adequate satellite reception.
- Which of these failure modes and hazards hold for the sense of compass this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Magnetic declination varies with location and time.
- Some magnetic compasses are balanced for particular magnetic zones; globally balanced designs accommodate a wider range of locations.
- Magnetic compasses become less useful near magnetic poles, where the horizontal component of Earth's magnetic field is weak.
- Which of these regional variation hold for the sense of compass 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.
- Drawing compass - A drawing compass constructs circles or transfers distances; it does not indicate a navigational reference direction.
- Magnetometer - A magnetometer measures a magnetic field; a compass provides a directional reference, sometimes using magnetometer measurements.
- GNSS receiver - A positioning receiver determines location and may derive course from motion; a satellite compass uses separated antennas to determine heading even while stationary.
- Gyroscope - A gyroscope senses rotation or maintains an orientation reference; a gyrocompass uses gyroscopic behavior to establish north.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of compass this model covers, and on what evidence? provenance
What the second pass must settle
- Does vr.tr.compass-q103896 denote the broad navigational instrument kind or only the magnetic compass, and how should gyrocompasses and satellite-based compasses relate to it?
- Does an existing Vercy world model already own this concept, requiring a registry link instead of a separate publication?
- Which standards and issuing bodies apply to each supported use context, particularly marine installation, and what conformity evidence do they require?
- What sourced ranges for accuracy, resolution, settling time, tilt tolerance, dimensions and environmental limits are meaningful for the included compass categories?
- Which manufacturer-supported checks distinguish acceptable capsule bubbles or transient instability from defects requiring service or replacement?