MRTKLIB v0.5.4 Release Notes¶

Release date: 2026-03-11 Type: Architecture / signals redesign Branch: feat/signals-architecture

Overview¶

v0.5.4 introduces a structured signals architecture that replaces the legacy string-based codepris[] system. The new mrtk_band_t enum defines 26 per-constellation physical frequency bands, and a structured priority table (SIG_PRIORITY_TABLE) serves as the single source of truth for signal selection.

TOML configs gain explicit signals = ["G1C", "G2W", "E1C", "E5Q"] arrays, replacing the opaque frequency = "l1+2" strings.

No algorithmic changes; all positioning output is identical to v0.5.3.

Changes¶

Added — mrtk_band_t enum and structured signal priority¶

• mrtk_band_t enum (mrtk_foundation.h) — 26 per-constellation physical frequency bands:
• GPS: L1, L2, L5
• GLONASS: G1, G2, G3
• Galileo: E1, E5a, E5b, E6, E5ab
• QZSS: L1, L2, L5, L6
• SBAS: L1, L5
• BDS: B1I, B1C, B2a, B2b, B2ab, B3
• NavIC: L5, S

• Plus MRTK_BAND_UNKNOWN and MRTK_BAND_MAX sentinels

• SIG_PRIORITY_TABLE (mrtk_obs.c) — 26-entry structured priority table using C99 designated initializers and CODE_* constants

• New API functions (mrtk_obs.h):

• mrtk_rinex_freq_to_band() — RINEX freq digit → band (incl. GLO CDMA aliases)
• mrtk_get_signal_priority() — (sys, band) → priority-ordered code array
• mrtk_band2freq_hz() — band → carrier frequency (Hz)
• mrtk_band_to_freq_num() — band → RINEX freq number (reverse mapping)
• mrtk_parse_signal_str() — parse "G1C" → (SYS_GPS, MRTK_BAND_GPS_L1, CODE_L1C)
• mrtk_sigcfg_from_signals() — build per-system signal config from string array

• mrtk_sigcfg_to_obsdef() — bridge signal config to obsdef tables

• New types (mrtk_obs.h / mrtk_opt.h):

• mrtk_signal_t — (band, preferred_code) pair
• mrtk_sigcfg_t — per-constellation signal config

• prcopt_t.sigcfg[7] / sigcfg_set — processing option fields

• TOML signals array (mrtk_toml.c) — [positioning] signals key accepts TOML string arrays, auto-deriving nf from configured signals

Changed — getcodepri / code2idx rewrite¶

• getcodepri() — Rewritten to use mrtk_rinex_freq_to_band() + mrtk_get_signal_priority() instead of legacy codepris[] string scan
• code2idx() — Rewritten as 3-stage pipeline: code2freq_num() → mrtk_rinex_freq_to_band() → band2idx_fixed()
• obsdef tables (mrtk_nav.c) — Annotated with mrtk_band_t names in comments (e.g., /* 0:L1 (MRTK_BAND_GPS_L1) */)
• CLASLIB/benchmark TOML configs — Migrated from frequency to signals arrays (11 files); old frequency lines commented out for reference

Removed — Legacy signal infrastructure¶

• codepris[7][MAXFREQ][16] — string-based signal priority array
• setcodepri() / get_codepris() — legacy priority access functions
• obsdef_t.codepris field — removed from struct and all 8 obsdef initializers
• 7 × code2freq_*() functions — replaced by band-based lookup pipeline

Fixed — Code review findings¶

• buff2sysopts() nf validation — reject nf > NFREQ from signal config
• code2idx() SYS_BD2 normalization — consistent with getcodepri()
• toml_val_to_str() snprintf buffer overflow — clamp advance on truncation
• NUM_PRIORITY_ENTRIES hardcoded constant — replaced with sizeof-based count
• Docstring corrections — signal format is "G1C" (not "GL1C")

Known Limitations¶

positioning.signals and [signals] section conflict¶

Configs that use the MADOCALIB per-system signal selection ([signals] gps, galileo, bds2, bds3, etc., mapped to pos2-sig*) cannot use positioning.signals at the same time. Both mechanisms call set_obsdef(), and the [signals] section overrides the obsdef ordering set by positioning.signals, causing incorrect frequency assignment.

Affected configs: MADOCALIB, MALIB, and benchmark/madoca TOML files retain frequency for now. A future release will unify these two mechanisms.

Scope¶

Test Results¶

56/56 non-realtime tests pass — unchanged from v0.5.3.