CorsikaAtmosphere#

class MCEq.geometry.density_profiles.CorsikaAtmosphere(location, season=None)[source]#

Bases: EarthsAtmosphere

Class, holding the parameters of a Linsley type parameterization similar to the Air-Shower Monte Carlo CORSIKA.

The parameters pre-defined parameters are taken from the CORSIKA manual. If new sets of parameters are added to init_parameters(), the array _thickl can be calculated using calc_thickl() .

_atm_param#

(5x5) Stores 5 atmospheric parameters _aatm, _batm, _catm, _thickl, _hlay for each of the 5 layers

Type:: numpy.array()

Parameters:

location (str) – see init_parameters()
season (str,optional) – see init_parameters()

Attributes Summary

`max_X`	Depth at altitude 0.
`max_den`	Density at altitude 0.
`s_X2rho`	Spline for conversion from depth to density.
`s_h2X`	Spline for conversion from altitude to depth.
`s_lX2h`	Spline for conversion from depth to altitude.

Methods Summary

`X2h`(X)	Returns the height above surface as a function of slant depth for currently selected zenith angle.
`X2rho`(X)	Returns the density \(\rho(X)\).
`calc_thickl`()	Calculates thickness layers for `depth2height()`
`calculate_density_spline`([n_steps])	Calculates and stores a spline of \(\rho(X)\).
`depth2height`(x_v)	Converts column/vertical depth to height.
`gamma_cherenkov_air`(h_cm)	Returns the Lorentz factor gamma of Cherenkov threshold in air (MeV).
`get_density`(h_cm)	Returns the density of air in g/cm**3.
`get_mass_overburden`(h_cm)	Returns the mass overburden in atmosphere in g/cm**2.
`h2X`(h)	Returns the depth along path as function of height above surface.
`init_parameters`(location, season)	Initializes `_atm_param` by fetching them from the atmosphere_parameters module.
`moliere_air`(h_cm)	Returns the Moliere unit of air for US standard atmosphere.
`nref_rel_air`(h_cm)	Returns the refractive index - 1 in air (density parametrization as in CORSIKA).
`r_X2rho`(X)	Returns the inverse density \(\frac{1}{\rho}(X)\).
`rho_inv`(X, cos_theta)	Returns reciprocal density in cm**3/g using planar approximation.
`set_h_obs`(h_obs)	Set the elevation of the observation (detector) level in cm.
`set_theta`(theta_deg)	Configures geometry and initiates spline calculation for \(\rho(X)\).
`theta_cherenkov_air`(h_cm)	Returns the Cherenkov angle in air (degrees).

Attributes Documentation

max_X#: Depth at altitude 0.

max_den#: Density at altitude 0.

s_X2rho#: Spline for conversion from depth to density.

s_h2X#: Spline for conversion from altitude to depth.

s_lX2h#: Spline for conversion from depth to altitude.

Methods Documentation

X2h(X)#

Returns the height above surface as a function of slant depth for currently selected zenith angle.

The spline s_lX2h is used, which was calculated or retrieved from cache during the set_theta() call.

Parameters:: X (float) – slant depth in g/cm**2
Returns:: height above surface in cm
Return type:: float h

X2rho(X)#

Returns the density \(\rho(X)\).

The spline s_X2rho is used, which was calculated or retrieved from cache during the set_theta() call.

Parameters:: X (float) – slant depth in g/cm**2
Returns:: \(\rho\) in cm**3/g
Return type:: float

calc_thickl()[source]#

Calculates thickness layers for depth2height()

The analytical inversion of the CORSIKA parameterization relies on the knowledge about the depth \(X\), where trasitions between layers/exponentials occur.

Example

Create a new set of parameters in init_parameters() inserting arbitrary values in the _thikl array:

$ cor_atm = CorsikaAtmosphere(new_location, new_season)
$ cor_atm.calc_thickl()

Replace _thickl values with printout.

calculate_density_spline(n_steps=2000)#

Calculates and stores a spline of \(\rho(X)\).

Parameters:: n_steps (int, optional) – number of \(X\) values to use for interpolation
Raises:: Exception – if set_theta() was not called before.

depth2height(x_v)[source]#

Converts column/vertical depth to height.

Parameters:: x_v (float) – column depth \(X_v\) in g/cm**2
Returns:: height in cm
Return type:: float

gamma_cherenkov_air(h_cm)#: Returns the Lorentz factor gamma of Cherenkov threshold in air (MeV).

get_density(h_cm)[source]#

Returns the density of air in g/cm**3.

Uses the optimized module function corsika_get_density_jit().

Parameters:: h_cm (float) – height in cm
Returns:: density \(\rho(h_{cm})\) in g/cm**3
Return type:: float

get_mass_overburden(h_cm)[source]#

Returns the mass overburden in atmosphere in g/cm**2.

Uses the optimized module function corsika_get_m_overburden_jit()

Parameters:: h_cm (float) – height in cm
Returns:: column depth \(T(h_{cm})\) in g/cm**2
Return type:: float

h2X(h)#

Returns the depth along path as function of height above surface.

The spline s_X2rho is used, which was calculated or retrieved from cache during the set_theta() call.

Parameters:: h (float) – vertical height above surface in cm
Returns:: X slant depth in g/cm**2
Return type:: float

init_parameters(location, season)[source]#

Initializes _atm_param by fetching them from the atmosphere_parameters module.

Parameters:

location (str) – The location identifier.
season (str, optional) – The season identifier.

Raises:

Exception – if parameter set not available (via get_atmosphere_parameters)

moliere_air(h_cm)#: Returns the Moliere unit of air for US standard atmosphere.

nref_rel_air(h_cm)#: Returns the refractive index - 1 in air (density parametrization as in CORSIKA).

r_X2rho(X)#

Returns the inverse density \(\frac{1}{\rho}(X)\).

The spline s_X2rho is used, which was calculated or retrieved from cache during the set_theta() call.

Parameters:: X (float) – slant depth in g/cm**2
Returns:: \(1/\rho\) in cm**3/g
Return type:: float

rho_inv(X, cos_theta)[source]#

Returns reciprocal density in cm**3/g using planar approximation.

This function uses the optimized function planar_rho_inv_jit()

Parameters:: h_cm (float) – height in cm
Returns:: \(\frac{1}{\rho}(X,\cos{\theta})\) cm**3/g
Return type:: float

set_h_obs(h_obs)#: Set the elevation of the observation (detector) level in cm.

set_theta(theta_deg)#

Configures geometry and initiates spline calculation for \(\rho(X)\).

If the option ‘use_atm_cache’ is enabled in the config, the function will check, if a corresponding spline is available in the cache and use it. Otherwise it will call calculate_density_spline(), make the function r_X2rho() available to the core code and store the spline in the cache.

Parameters:: theta_deg (float) – zenith angle \(\theta\) at detector

theta_cherenkov_air(h_cm)#: Returns the Cherenkov angle in air (degrees).