irfpy.jna.fov1

JNA FoV module

Conversion between $\theta$ $\phi$ system to a vector is implemented in frame module. See also How to convert between frames.

Definition of $\theta$ and $\phi$ is as follows. Primary axis is -z axis. $\theta$ is measured from xy plane and positive in -z axis. In other word, this is a co-latitude measured from -z axis. $\phi$ is measured from y axis (strictly speaking yz plane) and positive toward x axis. See Figure 1.1 in CENA calibration report.

irfpy.jna.fov1.shape_of_response(n, theta, phi)

Return the shape of response.

Parameters

• n – Channel ID from 0 to 10.

• theta – Elevation angle ($\theta$) in degrees. Should be -90 to 90.

• phi – Azimuthal angle ($\phi$) in degrees. Should be -180 to 180.

irfpy.jna.fov1.pixel_shape(n, elevresolution=0, azimresolution=0, resolution=None, fill=False)

Return an array of the pixel edge angle of its FWHM.

Parameters

• n – Channel number. 0 to 10.

• azimresolution – Azimuthal resolution. Number of division in azimuthal direction.

• elevresolution – Elevation resolution. Number of division in elevation direction.

• resolution – Resolution. Overwrite azimresolution and elevresolution.

• fill – If true, the first point is added to the end.

Returns

A tuple of 2 numpy array. Array of $\theta$ and array of $\phi$.

The number of elements is 4+2*azimresolution+2*elevresolution. If fill is True, one more element is added. However, it is recommend to check the number after you get the array.

>>> pix0 = pixel_shape(0, azimresolution=50, elevresolution=3)
>>> print(len(pix0[0]), len(pix0[1]))
110 110

irfpy.jna.fov1.azim_pix_center(n)

Returns the azimuth ($\phi$) center in degrees for the pixel n.

irfpy.jna.fov1.azim_pix_fwhm(n)

Returns the FWHM of the azimuthal directions ($\phi$) in degrees.

Assuming it does not depend on n. 15.0 degrees.

irfpy.jna.fov1.elev_pix_center(n)

Returns the elevation center ($\theta$) in degrees for the pixel n.

It does not indeed depend on n: Preliminary value -10.00 assumed, as of 2015-05, to be updated.

irfpy.jna.fov1.elev_pix_fwhm(n)

Returns the FWHM of the elevation ($\theta$) directions in degrees.

Independent of n Preliminaly value 8.00 assumed, as of 2015-05, to be updated.

irfpy.jna.fov1.solid_angle(n)

Returns the approximate soliad angle.

Equation (3.8) gives the definition.

$$\Delta\Omega_n \approx FWHM_{\phi,n} \cdot FWHM_{\theta,n}$$

>>> print('%.3f' % solid_angle(0))
0.037