Global Positioning System
Enable an AI agent to recognise the Global Positioning System, assess its positioning and timing service for a stated place, time and task, and decide whether to use, corroborate or suspend reliance on it.
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.
Researched by: Codex
Purpose and description
Enable an AI agent to recognise the Global Positioning System, assess its positioning and timing service for a stated place, time and task, and decide whether to use, corroborate or suspend reliance on it.
It can be Identify whether an observed positioning or timing service is GPS and record other contributing systems.; Match a receiver's declared capabilities to the GPS signals and service needed for a task.; Assess GPS availability and performance evidence for a particular location, interval and requirement.; Recommend exclusion of suspect observations or suspension of GPS reliance when evidence fails the task's acceptance conditions.; Select an independently supported fallback or corroboration method through linked neighbouring models.; Reassess reliance after an outage, interference report or signal-health change using explicit recovery evidence..
Distinguishing features
The referent is the named U.S.-owned positioning, navigation and timing utility, rather than GNSS as a class or another constellation. [GPS overview](https://www.gps.gov/gps)
The referent includes the satellite broadcast infrastructure and ground-control functions; a handset, antenna or dashboard navigator is equipment that uses it.
Basic GPS reception obtains one-way satellite broadcasts; a device transmitting its position to a tracking server is using an additional communications service. [GPS overview](https://www.gps.gov/gps)
A result described as GPS must identify whether GPS observations actually contributed; a device location label alone does not establish the positioning source.
Corrections or integrity information supplied by an augmentation service must be attributed separately from the underlying GPS service.
Scope
+ GPS identity and the boundary between the infrastructure, its services and participating user equipment
+ Constellation and ground-control contributions to usable satellite ranging and timing signals
+ Broadcast signal compatibility, navigation data, coordinate references and time references
+ Service health, coverage, availability and performance assessed for an explicit location and interval
+ Conditions for accepting, corroborating, rejecting or restoring reliance on GPS-derived outputs
+ Dependencies on external corrections, augmentation and other navigation systems
- Individual satellite construction, propulsion and maintenance procedures
- Receiver hardware design, firmware implementation and antenna installation procedures
- Independent models of Galileo, GLONASS, BeiDou and GNSS as a general class
- Operation of augmentation systems, correction networks and precise positioning services
- Maps, route planning, geocoding and vehicle guidance policies
- Tracking applications, location-history storage and personal-data governance
Characteristics
- Service and signal profile
- Named GPS service; signal and navigation-message types; applicable specification revision Determines which receiver capabilities, access conditions and performance statements apply.
- Assessment context
- Location or service region, observation interval and intended positioning or timing task Prevents a local reception problem or historical report from becoming an unqualified claim about the entire system.
- Satellite participation
- Satellite identities linked separately to operational status, visibility, tracking and use in a solution An operational satellite is not necessarily visible, tracked or suitable for a particular user's solution.
- Broadcast health assessment
- Reported healthy, reported unhealthy, conflicting evidence or unknown; per satellite and signal with timestamp Supports excluding unsuitable signals without treating a health indication as proof of local reception quality.
- Navigation-data freshness
- Seconds since relevant reference epoch or update, with message type and applicable validity rule Supports judging whether orbit, clock and related data remain suitable for the intended computation.
- Positioning error evidence
- Metres; horizontal or vertical; measured or estimated; confidence level, interval and reference truth Makes accuracy claims comparable and distinguishes estimated uncertainty from independently measured error.
- Timing error evidence
- Seconds or nanoseconds relative to a named time reference, with uncertainty and calibration conditions A usable position does not establish that a timing output meets the task's requirements.
- Observation geometry
- Dimensionless dilution-of-precision measure with type, epoch and contributing satellite set Records how satellite geometry affects the interpretation of ranging observations.
- Service availability evidence
- Percentage or duration meeting a declared criterion over a stated region and interval Availability is meaningful only when the qualifying service condition and denominator are explicit.
- Reference frame and time basis
- Named coordinate frame and realization, coordinate epoch, time scale and applied conversions Prevents apparently valid coordinates or timestamps from being combined under incompatible references.
- External assistance dependence
- Linked augmentation, correction, assistance or other-constellation service; contribution and freshness Separates GPS service capability from performance achieved through additional systems.
- Fitness for intended reliance
- Unassessed, acceptable, corroboration required or unacceptable, with task thresholds and evidence Connects observed service condition to a specific decision without declaring GPS universally safe or unsafe.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 10 layers · 10 findings · 20 questions.
GPS identity and service boundary Establish which system and GPS service the entry denotes and where receiver and augmentation responsibilities begin.
GPS is frequently used as a label for receivers, location applications and satellite navigation generally; these meanings require different state judgments.
Named system identity
Anchor the registry entry to the named GPS infrastructure and service.
GPS referent
Record evidence that the referent is the U.S.-owned PNT utility and identify its system boundary. [GPS overview](https://www.gps.gov/gps)
- Does this record denote the GPS system itself, a GPS service, or equipment colloquially called a GPS? definition
- Which authoritative description anchors the identity and infrastructure boundary? provenance
Service and augmentation boundaries
Separate the GPS service under assessment from externally supplied improvements.
Service attribution
Record the applicable GPS service and attribute assistance, corrections and mixed-constellation contributions separately.
- Which GPS service and access conditions apply to the intended user? definition
- Which claimed capabilities depend on augmentation, external corrections or another constellation? boundary
Constellation and control condition Represent the space and ground-control conditions that support usable GPS broadcasts.
A constellation count alone cannot establish whether suitable signals and maintained navigation data are available.
Satellite service contribution
Distinguish operational constellation membership from local usability.
Usable satellite set
Record satellite and signal identities, dated status evidence and their contribution to the assessed service.
- Which satellites and signals are reported operational at the assessment epoch, and by which source? provenance
- Which are visible, tracked and actually used at the assessed location, and what geometry results? measurement
Navigation data maintenance
Assess the evidence that broadcast orbit, clock and health information remains usable.
Broadcast data condition
Record relevant data epochs, validity conditions and notices affecting confidence in maintained broadcasts.
- How old are the applicable orbit and clock data, and do they meet the governing validity conditions? measurement
- Which dated operational notices identify maintenance, outages or control-related limitations affecting these signals? provenance
Ranging and reference interpretation Capture the signal, navigation-message and reference conventions needed to interpret GPS observations.
Receiving a signal does not establish that an agent can interpret its observations or combine its coordinates and timestamps correctly.
Signal and message compatibility
Relate available GPS broadcasts to the user's receiving and decoding capabilities.
Observation compatibility
Record the applicable broadcast interface and evidence of receiver compatibility. [GPS interface specifications](https://www.gps.gov/interface-control-documents-icds-interface-specifications-iss)
- Which GPS signals and navigation-message formats are required and supported for this use? definition
- Which interface specification revision and receiver capability evidence support that compatibility judgment? provenance
Coordinate and time references
Make position and time outputs interpretable across connected systems.
Reference consistency
Record the coordinate frame, height convention, epoch, time scale and transformations relevant to the requested output.
- What coordinate frame, height convention and time scale does the output actually use? definition
- Which transformations, time offsets or height conversions must be verified before combining this output with the target system? action
Service performance and local reception Distinguish system service commitments from performance experienced under particular receiving conditions.
An agent must avoid treating a service specification as a guarantee of every receiver's local accuracy or availability.
Performance evidence
Assess positioning and timing results against explicit service and task criteria.
Qualified performance assessment
Record applicable performance criteria, measurement conditions and observed compliance; GPS publishes service-specific performance standards. [GPS performance standards](https://www.gps.gov/performance-standards-specifications)
- Which accuracy, availability, continuity and timing criteria apply, over what interval and under which assumptions? definition
- What measured evidence or uncertainty estimates show whether the local output meets the task's thresholds? measurement
Local reception limitations
Record environmental and equipment conditions that may explain a local loss of performance.
Reception cause separation
Keep observations of obstruction, reflected signals, propagation conditions and receiver limitations distinct from confirmed constellation faults.
- What evidence characterises obstruction, multipath, propagation disturbance or receiver limitations at this location? measurement
- What observations distinguish a local reception problem from a satellite, signal or broader service problem? boundary
Trust and reliance decisions Translate signal and solution evidence into bounded decisions about using GPS.
A plausible position or timestamp may still be unsuitable; the model must support corroboration, exclusion and recovery decisions.
Anomaly and integrity evidence
Assess inconsistent or suspect GPS observations without asserting an unsupported cause.
Trustworthiness assessment
Record health indications, receiver alerts, independent comparisons and evidence for suspected interference or deceptive signals.
- Which health indications, integrity alerts or independent position and time comparisons support or challenge the output? measurement
- What evidence supports a diagnosis of interference or spoofing rather than ordinary reception error, and what remains uncertain? provenance
Use, suspension and recovery
Define task-specific reliance decisions and the evidence required to change them.
Reliance transition rules
Record acceptance thresholds, permitted interventions, fallback dependencies and conditions for restoring GPS reliance.
- Under what evidence thresholds should the agent accept the output, seek corroboration, exclude observations or suspend reliance? action
- What independent fallback is available, who may change operational use, and what evidence permits recovery? action
What the second pass must settle
- Does an existing Vercy world-model publication already own this GPS concept, requiring this registry entry to link to it?
- Which authoritative GPS service and interface revisions should anchor the researched publication, and which signal capabilities are operational at its reference date?
- Which sources provide sufficiently current satellite, signal and outage status, and how should conflicts or stale reports be represented?
- Which positioning and timing use cases require explicit integrity, continuity or recovery thresholds beyond the underlying GPS service specification?
- How much authenticated evidence about restricted services is available to the intended agents, and which capabilities must therefore remain unassessed?