RTK GPS

• 16 cols t, t_gps, lat, long, alt, p_x, p_y, p_z, v_x, v_y, v_z, cov_p_x, cov_p_y, cov_p_z, gps_fix_type, rtk_status.
  • Present on outdoor_1, transition_1..3, mars_1..19; absent on indoor.
  • 8.00 Hz (median dt 0.125 s; the README’s “7.98 Hz” is the gap-averaged figure). 0 NaN.
• cov_* are variances m²; RTK-fixed floor 1.96e-4 horizontal (σ 1.4 cm), 1.0e-4 vertical (σ 1.0 cm), rising in integer-mm² steps; RTK-float ~1.4e-2 (σ 12 cm). The horizontal floor saturates and does not track real geometry.
• rtk_status ∈ {1 fixed, 0 float, −1 invalid}; gps_fix_type ∈ {0, 2, 3}. −1 rows are diagnostic-only (they still carry positions). Fix quality varies per run and per receiver (e.g. outdoor_1 rtk_gps1 mostly float while rtk_gps2 mostly fixed; transitions have no-fix stretches).
• t == t_gps (GNSS clock) — see the GNSS-time trap on Time and Clocks. The system-clock-aligned lanes are *_data_revised and ground_truth_*.
• *_data_revised.csv (under <run>_sensors/ground_truth/): headerless, 7 cols t, lat, long, alt, v_x, v_y, v_z (ENU x,y,z dropped).
  • The 10-token format is advertised only in ground_truth/README.txt.
  • Row count differs from raw on several runs — no 1:1 index correspondence.
  • _data variants on mars_4/mars_8 are 13-col (t_sys, t_gps, lat, long, alt, x, y, z, v_x, v_y, v_z, fix_type, rtk_status).