beam_generator

pyoof.beam_generator(params, wavel, d_z, illum_func, telgeo, noise, resolution, box_factor)

Routine to generate data and test the pyoof package algorithm. It has the default setting for the pyoof fits file input.

Parameters:

params : ndarray

Two stacked arrays, the illumination and Zernike circle polynomials coefficients. params = np.hstack([I_coeff, K_coeff]).

wavel : float

Wavelength, \(\lambda\), in meters.

d_z : list

Radial offset \(d_z\), added to the sub-reflector in meters. This characteristic measurement adds the classical interference pattern to the beam maps, normalized squared (field) radiation pattern, which is an out-of-focus property. The radial offset list must be as follows, d_z = [d_z-, 0., d_z+] all of them in meters.

illum_func : function

Illumination function, \(E_\mathrm{a}(x, y)\), to be evaluated with the key I_coeff. The illumination functions available are illum_pedestal and illum_gauss.

telgeo : list

List that contains the blockage distribution, optical path difference (OPD) function, and the primary radius (float) in meters. The list must have the following order, telego = [block_dist, opd_func, pr].

noise : float

Noise amplitude added to the generated data. The noise comes from a random Gaussian, see normal.

resolution : int

Fast Fourier Transform resolution for a rectangular grid. The input value has to be greater or equal to the telescope resolution and with power of 2 for faster FFT processing. It is recommended a value higher than resolution = 2 ** 8.

box_factor : int

Related to the FFT resolution (resolution key), defines the image pixel size level. It depends on the primary radius, pr, of the telescope, e.g. a box_factor = 5 returns x = np.linspace(-5 * pr, 5 * pr, resolution), an array to be used in the FFT2 (fft2).

Returns:

pyoof_fits : HDUList

The output fits file is stored in the directory 'data_generated/'. Every time the function is executed a new file will be stored. The file is ready to use for the pyoof package.