Policy. Admit new terms only if they earn their place.
Training data.
calendar grid: daily or sparse (e.g., D1/D15), fixed time baseunwrap rule: carry+360soL_unwrapped(t)is continuous
OLS targets/design.
- Fixed-n (Moon/outer):
y = L_unwrapped - n*t;X = [1, sin(w*t), cos(w*t), ...] - Free-n (Sun/inner):
y = L_unwrapped;X = [1, t, sin(w*t), cos(w*t), ...]
Model score (BIC).BIC = k*log(N) + N*log( max(RSS/N, 1e-16) )
Event-aware loss (degree still dominant).loss = 1.0*MAE_deg + 0.3*cusp_MAE + 0.4*MAE_speed
Gate (strict).
Admit the extra term iff (BIC_extra <= BIC_base - 6) and (loss_extra < loss_base).
Selection guarantees.
- Parsimony: base wins unless an extra is decisively better (
DeltaBIC >= 6). - Event fidelity: crossings and stations influence selection, not just degree MAE.
- Midpoint anchor: reduces phase coupling and edge bias.
Navigation
Back: SSM-JTK – Ephemeris-independent planetary kernel (1.3)
Next: SSM-JTK – Reproducibility & audit trail (1.5)
SHUNYAYA 