Measurement And Engine Contracts

bijux-gnss-core owns the record meanings that must survive handoff between signal, receiver, navigation, infrastructure, and command crates. These records are not stage implementations; they are the shared language used by stage implementations.

Shared Measurement Flow

flowchart LR
    samples["SamplesFrame"]
    acquisition["AcqRequest and AcqResult"]
    tracking["tracking epochs and transitions"]
    observations["ObsEpoch and metadata"]
    navigation["NavSolutionEpoch and residuals"]
    artifacts["ArtifactV1 envelopes"]

    samples --> acquisition --> tracking --> observations --> navigation --> artifacts
    observations --> artifacts

Contract Families

family	owns	first proof
sample bridge	sample-frame records that cross source, signal, and receiver boundaries	observation source and core contract guide
acquisition records	request/result records and explainability payload meaning	observation source
tracking records	tracking epochs, transitions, uncertainty, and channel-state language	observation source
observation records	ObsEpoch, metadata, receiver roles, timing, rejection, and uncertainty classes	observation source
navigation-solution records	solution epochs, residuals, validity, lifecycle, and refusal classes	navigation-solution source
artifact envelopes	versioned cross-crate artifact headers, payload kinds, and validation traits	artifact source

Boundary Rules

• Core owns what exchanged records mean.
• Signal owns reusable signal computation before receiver stage execution.
• Receiver owns stage ordering and runtime artifacts that use these records.
• Navigation owns solver behavior that consumes and emits these records.
• Infra owns repository persistence around these records.
• Command owns operator routes and reports over these records.

Reader Checks

• Is the record shared by more than one crate?
• Would changing it alter persisted artifact interpretation or downstream solver assumptions?
• Can higher crates use the record without importing runtime, filesystem, or command policy?
• Does the proof live in core tests or in the crate that implements behavior over the record?

First Proof Check

Inspect the core contract guide, contract map, and serialization guide. Then inspect artifact, observation, and navigation-solution source for the record family that moved.