smiet.jax.synthesis module

class smiet.jax.synthesis.TemplateSynthesis(freq_ar: list = [30, 500, 100], ce_linear: bool = True)

Bases: object

This class is the main interface for synthesising pulses.

The main workflow consists of creating an instance and reading in the spectral parameters from a particular file. Then one can pass a SlicedShower as an origin to the TemplateSynthesis.make_template() method, which construct all the necessary arrays to perform the synthesis. To perform the synthesis, you then call the TemplateSynthesis.map_template() method with a Shower instance, which should be equipped with a longitudinal profile and the parameters from a Gaisser-Hillas fit.

Parameters:
freq_ar : list, default=[30, 500, 100]

The frequency range (min, max, central) in MHz for which to load the spectral parameters. Currently available options are:

  • [30, 500, 100] : can be used for most general purposes and experiments

  • [30, 80, 50] : a smaller sub-band which can be used for experiments such as LOFAR, AERA, etc

The default value is [30, 500, 100].

NOTE: The frequency range provided should not be multiplied by units.MHz, as this is done internally!

has_spectral_coefficients

Whether the spectral coefficients have been loaded

Type:

bool

atm

The atmosphere model from the origin shower, used to make the template

Type:

radiotools.atmosphere.models.Atmosphere

spectral_params

The spectral coefficients with shape {GEO, CE} x VIEW x FREQ

Type:

jax.typing.ArrayLike

viewing_angles

The viewing angles (in units of Cherenkov angle) for which we have the spectral coefficients

Type:

jax.typing.ArrayLike

amplitudes

The amplitude spectrum for each antenna, frequency, slice, and emission component

Type:

jax.typing.ArrayLike

phases

The phase spectrum for each antenna, frequency, slice, and emission component

Type:

jax.typing.ArrayLike

frequencies

The frequencies corresponding to the Fourier transform of the origin

Type:

np.ndarray

frequency_range

The minimum, maximum and central frequency for which the spectral parameters where fitted. This is read from the HDF5 file containing the spectral parameters.

Type:

tuple of float

freq_range_mask

A boolean mask to select only the frequencies within the frequency range

Type:

np.ndarray

truncated_frequencies

The frequencies after truncating all frequencies outside the frequency range

Type:

np.ndarray

n_samples

The number of time samples in the traces

Type:

int

delta_t

The time step between each time sample in the traces

Type:

float

antenna_information

The antenna information, containing the time axis, position, position in the shower plane, and name of each antenna

Type:

np.ndarray

n_antennas

The number of antennas in the template

Type:

int

template_information

The information about the template, such as the name, geometry, magnetisation, \(X_{max}\), core and creation time

Type:

dict

slices

The list of slices in the template, each as a SliceSynthesis object

Type:

list

grammages

The grammage at the bottom of each slice

Type:

list

Notes

It is implicitly assumed that the origin shower’s longitudinal profile is sampled with the same step size as the antennas are configured to observe (i.e. if the antennas are set up to observer slices with a thickness of 5 g/cm2, the longitudinal profile should also be sampled with a step size of 5 g/cm2 - which is set using the LONGI keyword in the CORSIKA input file).

calculate_arrival_times(shower: Shower) → Array

Calculate the arrival times of the shower at each antenna.

This will calculate the difference in distance between the radio emission that is generated from the atmospheric slices in the target shower (emission distnaces) and from each antenna to each atmospheric slice from the origin shower (travel distance), and calculate the time difference.

Parameters:
shower : Shower

The shower object containing the geometry (zenith, azimuth) and the core position.

Returns:

obs_time_difference – The time difference between the arrival of the shower front at each antenna.

Return type:

jax.Array

get_antenna_names() → list[str]

Get the names of all internal antennas.

Returns:

ant_names

Return type:

list of str

get_time_axis() → Array

Get the time axis for all antennas.

Returns:

time_axis – The time axis for each antenna, shaped as (# antennas, # time samples)

Return type:

np.ndarray

load_template(file_path, gdas_file: str | None = None) → None

Load the template from a saved state, as done by save_template().

Parameters:
file_path : str, default=None

the file path to load the template from.

gdas_file : str, default=None

the GDAS file to use for the atmosphere model. If None, then the model number from the loaded template will be used as the atmosphere object. Otherwise the provided GDAS file will be used. THe model number must be the same as that from CORSIKA.

make_template(origin: SlicedShower) → None

Process a SlicedShower into a template.

Parameters:
origin : smiet.jax.io.sliced_shower.SlicedShower

The origin shower

map_template(target: Shower) → Array

Map the template to a target profile, represented in a target Shower.

Calculates the trace for every antenna present in the template.

Parameters:
target : smiet.jax.io.base_shower.Shower

The target Shower object, containing the longitudinal profile, zenith, azimuth, geomagnetic angle, xmax and nmax

Returns:

total_synth – The synthesised geomagnetic & charge-excess trace for all antennas. Shape is {GEO, CE} x ANT x SAMPLES x 1

Return type:

jax.Array

map_template_to_slices(target: Shower) → Array

Map the template to a target profile, represented in a target Shower.

Calculates the trace for every antenna present in the template at all slices.

Parameters:
target : smiet.jax.io.base_shower.Shower

The target Shower object, containing the longitudinal profile, zenith, azimuth, geomagnetic angle, xmax and nmax

Returns:

total_synth – The synthesised geomagnetic & charge-excess trace for all antennas. Shape is {GEO, CE} x ANT x SAMPLES

Return type:

jax.Array

read_spectral_file(filename: str, ce_linear: bool = True) → None

Read spectral parameters from a file with filename in the spectral_parameters/ directory.

Parameters:
filename : str

The name of the spectral parameters file

remove_antennas(dcore_min: float = 15) → None

Remove antennas from the template based on their names.

In the future, this should be removed and should be implemented in SlicedShower instead.

Parameters:
dcore_min : float, default=15 * units.m

the minimum distance from the core to keep the antenna in the template. Antennas closer than this distance will be removed.

Return type:

None, but all objects related to the antennas will be truncated.

save_template(save_dir: str = '/home/kwatanabe/Projects/radio-ift/smiet-cr-synthesis/smiet/jax/../templates/jax', template_file: None | str = None) → None

Save the internal state of the synthesis class to disk.

Parameters:
template_file : str, default='default_template.h5'

the file to save the template into

save_dir : str, default='smiet/templates'

the directory to save the template into

truncate_atmosphere(starting_grammage: float = 200) → None

Truncate the starting point of the atmosphere grid, and subsequent arrays used for the synthesis process.

Parameters:
starting_grammage : float, default=200

the grammage in which we want to start the atmospheric grid, i.e. where we want to truncate from.

Return type:

None, but all objects related to the slices will be truncated.

smiet.jax.synthesis.amplitude_function(params: Array | ndarray | bool_ | number | bool | int | float | complex, frequencies: Array | ndarray | bool_ | number | bool | int | float | complex, d_noise: float = 0.0) → Array

Calculate the amplitude frequency spectrum corresponding to the parameters params.

Parameters:
params : jax.typing.ArrayLike

The spectral parameters. If it is a multidimensional array, the first dimension must contain the parameters.

frequencies : jax.typing.ArrayLike

The values of the frequencies to evaluate - remove central frequency beforehand!

d_noise : float, default=0.0

The noise floor level

Return type:

The evaluated amplitude frequency spectrum with shape VIEW x FREQ x SLICES

smiet.jax.synthesis.get_correction_factors(spectral_params: Array | ndarray | bool_ | number | bool | int | float | complex, ant_v_angles: Array | ndarray | bool_ | number | bool | int | float | complex, v_angles_grid: list, outshape: tuple) → Array

Get the correction factors from the spectral parameters.

Parameters:
spectral_params : jax.typing.ArrayLike

the spectral parameters for the geomagnetic and charge excess emission in shape {GEO x CE} x VIEW x FREQ x SLICES

ant_v_angles : jax.typing.ArrayLike

the viewing angles for the particular geometry & atmosphere

v_angles_grid : list, static

the grid of viewing angles used for interpolation

outshape : tuple, static

the shape for the correction factor array shape should be {GEO x CE} x ANTS x FREQ x SLICES

Returns:

correction_factors – the corrections factors in shape {GEO x CE} x ANTS x FREQ x SLICES

Return type:

jax.typing.ArrayLike

smiet.jax.synthesis.get_spectra(xmax: float, spectral_coeffs: Array | ndarray | bool_ | number | bool | int | float | complex, grammages: Array | ndarray | bool_ | number | bool | int | float | complex, frequencies: list) → Array | ndarray | bool_ | number | bool | int | float | complex

Retrieve the amplitude spectra at the specified frequencies, for a given \(\Delta X_{max}\).

Parameters:
xmax : float

The maximum of the atmospheric depth in g/cm^2

spectral_coeffs : jax.typing.ArrayLike

the spectral coefficients stored with shape {GEO, CE} x VIEW x FREQ

grammages : jax.typing.ArrayLike

an array of atmospheric depths in g/cm^2

frequencies : list

The list of frequencies at which to evaluate the spectra (after filtering)

Returns:

spectrum – the amplitude spectrum in shape {GEo x CE} x VIEW x FREQ x SLICES

Return type:

jax.typing.ArrayLik