pybsm.otf.functional.hufnagel_valley_turbulence_profile

pybsm.otf.functional.hufnagel_valley_turbulence_profile(*, h: ndarray, v: float, cn2_at_1m: float) → ndarray

Replaces IBSM Equations 3-6 through 3-8. The Hufnagel-Valley Turbulence profile.

Replaces IBSM Equations 3-6 through 3-8. The Hufnagel-Valley Turbulence profile (i.e. a profile of the refractive index structure parameter as a function of altitude). I suggest the HV profile because it seems to be in more widespread use than the profiles listed in the IBSM documentation. This is purely a personal choice. The HV equation comes from Roggemann et al., “Imaging Through Turbulence”, CRC Press (1996). The often quoted HV 5/7 model is a special case where Cn2at1m = 1.7e-14 and v = 21. HV 5/7 should result in a 5 cm coherence diameter (r0) and 7 urad isoplanatic angle along a vertical slant path into space.

Parameters:

  • h – height above ground level in (m)

  • v – the high altitude windspeed (m/s)

  • cn2_at_1m – the refractive index structure parameter “near the ground” (e.g. at h = 1 m)

Returns:

cn2 :

refractive index structure parameter as a function of height (m^(-2/3))