test_windStepLag

Test that the wind base class evaluates the spacecraft state extrapolated to the step midpoint.

test_windStepLag.test_air_velocity_is_evaluated_at_extrapolated_position()

Verify the co-rotating air velocity uses the state advanced by half of the message age.

A state with a velocity along x, written at the start of the simulation and rewritten one step later, must give the air velocity of the position advanced by v * dt / 2, which differs from the static one along y. The same state written at the current time is not advanced.

test_windStepLag.test_translating_planet_does_not_change_the_air_velocity()

Verify the spacecraft and the planet are evaluated at the same epoch.

The spacecraft and the planet move together at 30 km/s, so the relative position and the air velocity are constant.