def _setup_gridbeam_interpolation(self):
# grid beam coordinates
self._x_grid = self._primary_beam.phi[:]
self._y_grid = self._primary_beam.theta[:]
# celestial coordinates
angpos = hputil.ang_positions(self._nside)
x_cel = coord.sph_to_cart(angpos).T
# rotate to telescope coords
# first align y with N, then polar axis with NCP
self._x_tel = cylbeam.rotate_ypr(
(1.5 * np.pi, np.radians(90.0 - self.latitude), 0), *x_cel)
# mask any pixels outside grid
x_t, y_t, z_t = self._x_tel
self._pix_mask = ((z_t > 0)
& (np.abs(x_t) < np.abs(self._x_grid.max()))
& (np.abs(y_t) < np.abs(self._y_grid.max())))
# pre-compute polarisation pattern
# taken from driftscan
zenith = np.array([np.pi / 2.0 - np.radians(self.latitude), 0.0])
that, phat = coord.thetaphi_plane_cart(zenith)
xhat, yhat, zhat = cylbeam.rotate_ypr([-self.rotation_angle, 0.0, 0.0],
phat, -that,
coord.sph_to_cart(zenith))
self._pvec_x = cylbeam.polpattern(angpos, xhat)
self._pvec_y = cylbeam.polpattern(angpos, yhat)
def _init_trans(self, nside):
## Internal function for generating some common Healpix maps (position,
## horizon). These should need to be generated only when nside changes.
# Angular positions in healpix map of nside
self._nside = nside
self._angpos = hputil.ang_positions(nside)
# The horizon function
self._horizon = visibility.horizon(self._angpos, self.zenith)
def _init_trans(self, nside):
## Internal function for generating some common Healpix maps (position,
## horizon). These should need to be generated only when nside changes.
# Angular positions in healpix map of nside
self._nside = nside
self._angpos = hputil.ang_positions(nside)
# The horizon function
self._horizon = visibility.horizon(self._angpos, self.zenith)
def Omega(self):
r"""Return the beam solid angle :math:`\int |A(\boldsymbol{n})|^2 \ d^2\boldsymbol{n}`."""
nside = 256
angpos = hputil.ang_positions(nside)
lat = np.radians(44.15268333) # exact value not important
lon = np.radians(91.80686667) # exact value not important
zenith = np.array([0.5*np.pi - lat, lon])
horizon = visibility.horizon(angpos, zenith)
pxarea = (4 * np.pi / (12 * nside**2))
om = np.zeros_like(self.freqs)
for fi in xrange(len(self.freqs)):
width = self.width / (const.c / (1.0e9 * self.freqs[fi]))
beam = cylbeam.beam_amp(angpos, zenith, width, self.fwhm_h, self.fwhm_h)
om[fi] = np.sum(np.abs(beam)**2 * horizon) * pxarea
return om
def _init_trans(self, nside):
## Internal function for generating some common Healpix maps (position,
## horizon). These should need to be generated only when nside changes.
# Angular positions in healpix map of nside
self._nside = nside
self._angpos = hputil.ang_positions(nside)
# The horizon function
self._horizon = visibility.horizon(self._angpos, self.zenith)
# size of the cartesian projection
phi_size = 5 * self._nside + 1 # add 1 to make it odd for nside >= 2
theta_range = self.beam_theta_range
theta_size = ((theta_range[1] - theta_range[0]) / 180.0) * (phi_size / 2)
theta_size = theta_size if (np.mod(theta_size, 2) == 1) else theta_size+1 # make it odd
latra = [ 90.0-theta_range[1], 90.0-theta_range[0] ]
self._cart_projector = hpproj.CartesianProj(xsize=phi_size, ysize=theta_size, latra=latra)
def visualize_beam(args):
angpos = hputil.ang_positions(args.nside)
zenith = latlon_to_sphpol([args.lat, args.lon])
beamx_resp = beamx(args.feed, args.freq, angpos, zenith, args.dish_width)
beamy_resp = beamy(args.feed, args.freq, angpos, zenith, args.dish_width)
# Create output image file name
if args.outfile:
out_file = args.outfile
else:
freq = ('%s'%args.freq).replace('.', '_')
diameter = ('%s'%args.dish_width).replace('.', '_')
out_file = 'beam_resp_%s__%s.%s'%(freq, diameter, args.figfmt)
# Plot and save image
fig = plt.figure(1, figsize=(args.figlength, args.figwidth))
title1 = 'X beam pattern, f= %sMHz, d = %sm'%(args.freq, args.dish_width)
healpy.mollview(beamx_resp[:, 1], fig=1, sub=121, title=title1, min=args.min, max=args.max)
title2 = 'Y beam pattern, f= %sMHz, d = %sM'%(args.freq, args.dish_width)
healpy.mollview(beamy_resp[:, 0], fig=1, sub=122, title=title2, min=args.min, max=args.max)
if args.grid:
healpy.graticule()
fig.savefig(out_file)
fig.clf()
def _init_trans(self, nside):
## Internal function for generating some common Healpix maps (position,
## horizon). These should need to be generated only when nside changes.
# Angular positions in healpix map of nside
self._nside = nside
self._angpos = hputil.ang_positions(nside)
# The horizon function
self._horizon = visibility.horizon(self._angpos, self.zenith)
# size of the cartesian projection
phi_size = 5 * self._nside + 1 # add 1 to make it odd for nside >= 2
theta_range = self.beam_theta_range
theta_size = (
(theta_range[1] - theta_range[0]) / 180.0) * (phi_size / 2)
theta_size = theta_size if (np.mod(theta_size, 2)
== 1) else theta_size + 1 # make it odd
latra = [90.0 - theta_range[1], 90.0 - theta_range[0]]
self._cart_projector = hpproj.CartesianProj(xsize=phi_size,
ysize=theta_size,
latra=latra)
def rotate_phi(map, dphi):
angpos = hputil.ang_positions(healpy.npix2nside(map.size))
theta, phi = angpos[:, 0], ((angpos[:, 1] - dphi) % (2*np.pi))
return healpy.get_interp_val(map, theta, phi)
def visualize_cyl_beam(args):
"""Visualize cylinder beam.
"""
import numpy as np
import healpy
import hpvisual
from drift.telescope import cylinder as cyl
# from drift.core import telescope as tel
from cora.util import hputil
import matplotlib
matplotlib.use('Agg')
from matplotlib import pyplot as plt
from matplotlib.ticker import MultipleLocator
if args.pol:
pol_cyl = cyl.PolarisedCylinderTelescope(args.lat, args.lon)
# pol_cyl.zenith = tel.latlon_to_sphpol([args.lat, args.lon]) # NOTE: this is wrong, use the constructor above or the following assignment, because the assignment will automatically trigger drift/util/config.py __set__() method, which will call tel.latlon_to_sphpol.
# pol_cyl.zenith = [args.lat, args.lon]
pol_cyl.cylinder_width = args.cyl_width
pol_cyl._frequencies = np.array([args.freq])
pol_cyl._angpos = hputil.ang_positions(args.nside)
beamx_resp = pol_cyl.beamx(args.feed, 0)
beamy_resp = pol_cyl.beamy(args.feed, 0)
# Create output image file name
if args.outfile:
out_file = args.outfile
else:
freq = ('%s'%args.freq).replace('.', '_')
cyl_width = ('%s'%args.cyl_width).replace('.', '_')
out_file = 'pol_cyl_beam_resp_%s__%s.%s'%(freq, cyl_width, args.figfmt)
# Plot and save image
fig1 = plt.figure(1, figsize=(args.figlength, 2*args.figwidth))
title11 = 'X feed theta direction, f = %s MHz, w = %s m'%(args.freq, args.cyl_width)
title12 = 'X feed phi direction, f = %s MHz, w = %s m'%(args.freq, args.cyl_width)
hpvisual.mollview(beamx_resp[:, 0], fig=1, sub=221, title=title11, min=args.min, max=args.max)
hpvisual.mollview(beamx_resp[:, 1], fig=1, sub=222, title=title12, min=args.min, max=args.max)
title21 = 'Y feed theta direction, f = %s MHz, w = %s m'%(args.freq, args.cyl_width)
title22 = 'Y feed phi direction, f = %s MHz, w = %s m'%(args.freq, args.cyl_width)
hpvisual.mollview(beamy_resp[:, 0], fig=1, sub=223, title=title21, min=args.min, max=args.max)
hpvisual.mollview(beamy_resp[:, 1], fig=1, sub=224, title=title22, min=args.min, max=args.max)
if args.grid:
healpy.graticule()
fig1.savefig(out_file)
fig1.clf()
# R_{I to I}
II_resp = (beamx_resp[:, 0]**2 + beamx_resp[:, 1]**2 + beamy_resp[:, 0]**2 + beamy_resp[:, 1]**2) / 2.0
# R_{P to I}
PI_resp = (beamx_resp[:, 0]**2 - beamx_resp[:, 1]**2 + beamx_resp[:, 0]*beamx_resp[:, 1] + beamy_resp[:, 0]**2 - beamy_resp[:, 1]**2 + beamy_resp[:, 0]*beamy_resp[:, 1]) / 2.0
# Plot the R_{I to I}response
fig2 = plt.figure(2, figsize=(args.figlength, args.figwidth))
hpvisual.mollview(II_resp, fig=2, min=args.min, max=args.max)
if args.grid:
healpy.graticule()
fig2.savefig('II_mollview' + out_file)
fig2.clf()
# Plot the R_{P to I}response
fig3 = plt.figure(3, figsize=(args.figlength, args.figwidth))
hpvisual.mollview(PI_resp, fig=3, min=args.min, max=args.max)
if args.grid:
healpy.graticule()
fig3.savefig('PI_mollview' + out_file)
fig3.clf()
# cart_array = healpy.cartview(II_resp, fig=3, lonra=[-10, 10], min=args.min, max=args.max, aspect=0.25, notext=True, hold=True, title='', return_projected_map=True)
lon_range = [-10, 10]
ext = (-10, 10, -90, 90)
# R_{I to I } cartesian
II_cart = hpvisual.cartview(II_resp, lonra=lon_range, return_projected_map=True)
ticks = np.linspace(np.min(II_cart), np.max(II_cart), 6)
ticks = np.around(ticks, decimals=1)
plt.figure(figsize=(4, 5))
plt.imshow(II_cart, extent=ext, aspect=0.2, origin='lower', vmin=ticks[0], vmax=ticks[-1])
ax = plt.gca()
ax.yaxis.set_major_locator(MultipleLocator(30))
plt.xlabel('EW / deg')
plt.ylabel('NS / deg')
cbar = plt.colorbar(shrink=0.6 ,orientation='horizontal', ticks=ticks)
cbar.solids.set_rasterized(True)
plt.savefig('II_cartview_' + out_file)
# R_{P to I } cartesian
PI_cart = hpvisual.cartview(PI_resp, lonra=lon_range, return_projected_map=True)
ticks = np.linspace(np.min(PI_cart), np.max(PI_cart), 4)
ticks = np.around(ticks, decimals=2)
plt.figure(figsize=(4, 5))
plt.imshow(PI_cart, extent=ext, aspect=0.2, origin='lower', vmin=ticks[0], vmax=ticks[-1])
ax = plt.gca()
ax.yaxis.set_major_locator(MultipleLocator(30))
plt.xlabel('EW / deg')
plt.ylabel('NS / deg')
cbar = plt.colorbar(shrink=0.6 ,orientation='horizontal', ticks=ticks)
cbar.solids.set_rasterized(True)
plt.savefig('PI_cartview_' + out_file)
else:
unpol_cyl = cyl.UnpolarisedCylinderTelescope(args.lat, args.lon)
unpol_cyl.cylinder_width = args.cyl_width
unpol_cyl._frequencies = np.array([args.freq])
unpol_cyl._angpos = hputil.ang_positions(args.nside)
beam_amp = unpol_cyl.beam(args.feed, 0)
# Create output image file name
if args.outfile:
out_file = args.outfile
else:
freq = ('%s'%args.freq).replace('.', '_')
cyl_width = ('%s'%args.cyl_width).replace('.', '_')
out_file = 'unpol_cyl_beam_resp_%s__%s.%s'%(freq, cyl_width, args.figfmt)
# Plot and save image
fig = plt.figure(1, figsize=(args.figlength, args.figwidth))
title = 'Beam pattern, f = %s MHz, w = %s m'%(args.freq, args.cyl_width)
hpvisual.mollview(beam_amp, fig=1, sub=111, coord='G', title=title, min=args.min, max=args.max)
if args.grid:
healpy.graticule()
fig.savefig(out_file)
fig.clf()
