def get_resample_freq_step(
        central_freq: float,
        velocity_resolution_kms: float
) -> float:
    """
    Consider: abs(delta_f) = abs(delta_v) * (f / c)
    Here we choose f to be central_freq for the whole band.
    """
    c = 299792.458  # km/s
    return velocity_resolution_kms * central_freq / c