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feat(gps): add timer-based assisted reacquisition

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Remove the fixed pseudorange start offset, preserve per-PRN navigation assistance across RF loss and power cycles, and seed coherent navigation measurement phase on reacquisition. Add full LNAV almanac visibility scheduling, power-safe QSPI journaling, RF-domain reset isolation, and PPS Gray CDC hardening with Linux, sanitizer, RTL, and end-to-end coverage.
This commit is contained in:
onur
2026-08-04 02:52:35 +03:00
parent 347e1c671d
commit 30179df8e6
69 changed files with 6162 additions and 247 deletions
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soc/software/pps_python/simulate_pps.py
+6 -8
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@@ -22,7 +22,6 @@ try:
DEFAULT_IONO,
POSTPONE_TOW_S,
RF_HZ,
START_OFFSET_S,
TRACKING_HZ,
ReceiverEpochSimulator,
build_clock_trajectory,
@@ -41,7 +40,6 @@ except ImportError: # allow: python3 pps_python/simulate_pps.py
DEFAULT_IONO,
POSTPONE_TOW_S,
RF_HZ,
START_OFFSET_S,
TRACKING_HZ,
ReceiverEpochSimulator,
build_clock_trajectory,
@@ -321,7 +319,7 @@ def simulate_startup_tow(
"first_flight_s": first_flight,
# Parsed HOW labels transmit subframe time, not receive-now.
"how_as_receive_error_s": -(POSTPONE_TOW_S + first_flight),
"how_plus_pipeline_startoffset_error_s": START_OFFSET_S - first_flight,
"how_plus_pipeline_without_wls_error_s": -first_flight,
"wls_aligned_error_s": wls_error,
# Old receive reference written as if it were valid at APB-now.
"apb_now_error_s": wls_error - sampled_latency,
@@ -349,13 +347,13 @@ def plot_startup_tow(output_dir: Path, startup: dict[str, np.ndarray]) -> None:
axes[0, 1].grid(True, alpha=0.3)
axes[1, 0].hist(
startup["how_plus_pipeline_startoffset_error_s"] * 1.0e3,
startup["how_plus_pipeline_without_wls_error_s"] * 1.0e3,
bins=35,
color="tab:orange",
alpha=0.8,
)
axes[1, 0].set_xlabel("Phase error [ms]")
axes[1, 0].set_title("Provisional: HOW + 180 ms + 68.802 ms")
axes[1, 0].set_title("Still wrong: HOW + 180 ms without WLS flight time")
axes[1, 0].grid(True, alpha=0.3)
axes[1, 1].hist(
@@ -398,7 +396,7 @@ def build_summary(
f"derived GPS reference RMS error: {finite_rms(timing_error)*1e9:.3f} ns",
f"capture-to-commit delay mean/p99: {np.mean(latency)*1e3:.3f} / {np.percentile(latency, 99)*1e3:.3f} ms",
f"first HOW used as receive-now, median phase error: {np.median(startup['how_as_receive_error_s'])*1e3:.3f} ms",
f"first HOW + 180 ms + 68.802 ms, median phase error: {np.median(startup['how_plus_pipeline_startoffset_error_s'])*1e3:.3f} ms",
f"first HOW + 180 ms without WLS, median phase error: {np.median(startup['how_plus_pipeline_without_wls_error_s'])*1e3:.3f} ms",
]
for start, stop, label in [
(0.0, 20.0, "4 satellites"),
@@ -426,8 +424,8 @@ def build_summary(
[
"",
"Interpretation:",
"- bias/c is millisecond-scale because it contains the 68.802 ms synthetic datum and the minimum satellite path.",
"- epoch-aligned TOW (first delivery: HOW + 180 ms) + STARTOFFSET - bias/c reconstructs GPS time at the paired timestamp.",
"- bias/c is millisecond-scale because the timer-difference datum contains the negative reference-satellite path.",
"- epoch-aligned TOW (first delivery: HOW + 180 ms) - bias/c reconstructs GPS time at the paired timestamp.",
"- treating that old reference as valid at APB arrival converts software latency into PPS phase error.",
"- timestamping removes that phase misassociation; control application delay remains only as loop delay.",
"- baremetal applies the fixed 180 ms readout correction once; the PPS peripheral must not add it again.",