GPS L1 C/A Reference

Use this page when the reader needs the stable GPS L1 C/A signal profile before opening code, tests, or receiver behavior. The signal crate owns these facts; the receiver crate owns acquisition, tracking, and lock policy built on them.

Stable Signal Facts

fact	value	repository meaning
constellation	GPS	shared identity is Constellation::Gps
band	L1	shared identity is SignalBand::L1
code	C/A	shared identity is SignalCode::Ca
carrier frequency	1575.42 MHz	catalog and wavelength helpers derive carrier-dependent values
code rate	1.023 MHz	sampling and replica helpers use this as the nominal chip rate
primary-code length	1023 chips	one primary period is one complete C/A sequence
primary-code period	1 ms	receiver stages should not infer longer data-bit behavior from this page

Ownership Route

flowchart LR
    facts["GPS L1 C/A facts"]
    code["ca_code.rs<br/>chips and sampling"]
    catalog["catalog.rs<br/>signal identity"]
    dsp["dsp replica helpers"]
    receiver["bijux-gnss-receiver<br/>acquisition and tracking"]

    facts --> code
    facts --> catalog
    code --> dsp
    catalog --> receiver
    dsp --> receiver

What This Page Proves

• The C/A sequence is a 1023-chip primary code with a 1 ms nominal period.
• Public signal identity must route through the registry instead of hard-coded caller assumptions.
• Replica and sampling behavior belongs in signal only while it remains reusable substrate.
• Receiver defaults are downstream choices and must be proven in receiver docs, receiver tests, or emitted receiver artifacts.

When To Leave This Page

reader question	better owner
How is the C/A sequence generated or sampled?	the C/A code source
How is the signal exposed to other crates?	the signal catalog and public API surface
How does an acquisition search use this signal?	the receiver acquisition-to-tracking contract
How does tracking interpret phase, lock, or CN0?	the receiver tracking-to-observation contract and diagnostic contracts
How does navigation use decoded GPS data?	the navigation time and model contracts

First Proof Check

Start with the C/A code source and the signal catalog. Then confirm behavior through the reference chip test, the period-length test, and the long-duration phase test.