# GNSS availability from REAL satellite geometry, via two-line element sets.
#
# Instead of a synthetic Walker pattern, the constellation is parsed from a block
# of TLEs (the standard NORAD/Celestrak format) given inline below. Drop in the
# current GPS/Galileo/etc. element sets from celestrak.org to study coverage for
# an actual constellation. Here a small GPS-like MEO set (i = 55 deg, ~12 h orbit,
# six planes) is seen by a low-Earth-orbit user.
#
# Scope: the engine reads each TLE's mean Keplerian elements and propagates them
# two-body — it is NOT an SGP4 propagator (accurate near epoch; use elements from
# a common epoch). Vendor-neutral.

kind = "orbit"
seed = 13
threshold_ns = 10.0
mask_deg = 5.0
sigma_uere_m = 1.0

[time]
step_s = 120.0
duration_s = 43200.0   # ~ one GPS revolution

# Low-Earth-orbit user (~500 km), looking up at the MEO constellation.
[user]
altitude_km = 500.0
inclination_deg = 51.6
u0_deg = 0.0

# Real-format TLEs: six GPS-like satellites spread over six orbital planes.
[constellation]
tle = """
2 41001  55.0000   0.0000 0073892 201.7677   0.0000  2.00568623 70561
2 41002  55.0000  60.0000 0073892 201.7677  60.0000  2.00568623 70561
2 41003  55.0000 120.0000 0073892 201.7677 120.0000  2.00568623 70561
2 41004  55.0000 180.0000 0073892 201.7677 180.0000  2.00568623 70561
2 41005  55.0000 240.0000 0073892 201.7677 240.0000  2.00568623 70561
2 41006  55.0000 300.0000 0073892 201.7677 300.0000  2.00568623 70561
"""

[clock_quantum]
id = "optical-sr-lattice"
provenance = "Strontium optical lattice clock, space-oriented goal sigma_y(1s)=1e-15 (arXiv:1503.08457); not flown."
y0 = 1.0e-15
q_wf = 1.0e-30
q_rw = 1.0e-40

[clock_classical]
id = "csac-sa45s"
provenance = "Microchip SA.45s / SA65 chip-scale atomic clock, sigma_y(1s)=3.0e-10 (datasheet); deployed commercial part."
y0 = 1.0e-11
q_wf = 9.0e-20
q_rw = 1.0e-28
