Default hit-zone radius (meters) around the point of aim at the target plane — a 30 cm
circle. Shared by the CLI, FFI, and WASM so “hit probability” means the same thing everywhere.
Estimate a BC by fitting a simulated trajectory to measured data, for a chosen drag
model (G1, G7, …) and fit basis (drop or velocity). Uses a coarse 0.01 sweep over
plausible BCs followed by a 0.001 local refine around the coarse best.
Interpolate a muzzle velocity (m/s) from a measured powder-temperature curve at
temp_c (Celsius). curve is (temperature_celsius, velocity_m_s) points; it is
sorted ascending by temperature before use. Values below the first point or above
the last are CLAMPED to the endpoint velocity (no extrapolation beyond measured
data), and segments are linearly interpolated. A single point yields a constant.