# Navigation readiness review

## Gate result

The standalone receiver path decoded SignalSim RF samples without consuming
simulator ephemeris, satellite states, transmit times, receiver truth, or RINEX
fields. The RINEX source was opened only by a separate post-decode comparison.

The reproducible `navigation_multisat` vector contains 131,758,308 complex IQ8
samples (32.2 s at 4.092 MHz), SHA-256
`b38393b32eec2df53f9813ea7ff8f13e5e0fc72fa5cb7fb910a2b8f907a56a6e`.

| Criterion | Evidence | Result |
| --- | --- | ---: |
| E1B prompts and raw symbols from tracked RF | Five `prompt_epochs.npz`, `soft_symbols.npy`, and `hard_symbols.bin` artifact sets | PASS |
| Stable symbol and page synchronization | Repeated 250-symbol sync confirmation; 146 synchronized page parts | PASS |
| Deinterleaving | Official Annex D.2 coded vector plus RF pages | PASS |
| Soft-decision FEC | Independent Annex D.2 vector; all 70 received pages FEC-valid | PASS |
| CRC | Independent CRC-24Q check vector; 70 pass, 0 fail | PASS |
| Critical words | Types 1–6 decoded and typed | PASS |
| Complete ephemeris | PRNs 1, 4, 21, and 27; atomic matching IODnav sets | PASS |
| Satellite clock | Word 4 clock polynomial for all four complete satellites | PASS |
| Galileo time | GST week 1138, TOW 554765 s from tracked page data | PASS |
| Health and validity | Four complete satellites report usable E1B health and DVS | PASS |
| Independent truth comparison | Every ephemeris/clock field within 0.5 broadcast LSB; GST within its 1 s resolution | PASS |
| Reproducible artifacts | Prompt, symbol, page, FEC, CRC, word, ephemeris and summary evidence per PRN | PASS |
| Decoder truth isolation | Collection report records `decoder_truth_inputs: []` | PASS |

PRN 19 deliberately demonstrates the incomplete-data behavior: it received
word types 2–6 but not word 1 during the observation, so no ephemeris was
fabricated or committed. The other four satellites satisfy the readiness gate.

PVT has not been implemented or started in this milestone.

NAVIGATION DATA READY FOR PVT