def from_tree_transform(self, node):
if node['direction'] == 'native2celestial':
return rotations.RotateNative2Celestial(node["phi"], node["theta"],
node["psi"])
elif node['direction'] == 'celestial2native':
return rotations.RotateCelestial2Native(node["phi"], node["theta"],
node["psi"])
else:
return rotations.EulerAngleRotation(node["phi"],
node["theta"],
node["psi"],
axes_order=node["direction"])
def project_to_tangent_plane(ra, dec, ra_ref, dec_ref, scale=1.):
"""Convert ra/dec coordinates into pixel coordinates using a tangent plane projection.
Theprojection's reference point has to be specified.
Scale is a convenience parameter that defaults to 1.0, in which case the returned pixel
coordinates are also in degree. Scale can be set to a pixel scale to return detector coordinates
in pixels
Parameters
----------
ra : float
Right Ascension in decimal degrees
dec: float
declination in decimal degrees
ra_ref : float
Right Ascension of reference point in decimal degrees
dec_ref: float
declination of reference point in decimal degrees
scale : float
Multiplicative factor that is applied to the returned values. Default is 1.0
Returns
-------
x,y : float
pixel coordinates in decimal degrees if scale = 1.0
"""
# for zenithal projections, i.e. gnomonic, i.e. TAN:
if isinstance(ra_ref, u.Quantity):
lonpole = 180. * u.deg
else:
lonpole = 180.
# tangent plane projection from phi/theta to x,y
tan = astmodels.Sky2Pix_TAN()
# compute native coordinate rotation to obtain phi and theta
rot_for_tan = astrotations.RotateCelestial2Native(ra_ref, dec_ref, lonpole)
phi_theta = rot_for_tan(ra, dec)
# pixel coordinates, x and y are in degree-equivalent
x, y = tan(phi_theta[0], phi_theta[1])
x = x * scale
y = y * scale
return x, y
def from_yaml_tree_transform(self, node, tag, ctx):
from astropy.modeling import rotations
if node["direction"] == "native2celestial":
return rotations.RotateNative2Celestial(node["phi"], node["theta"],
node["psi"])
elif node["direction"] == "celestial2native":
return rotations.RotateCelestial2Native(node["phi"], node["theta"],
node["psi"])
else:
return rotations.EulerAngleRotation(node["phi"],
node["theta"],
node["psi"],
axes_order=node["direction"])
def aberrator(arr, ra, dec, v):
gamma = 1. / np.sqrt(1 - (v / c)**2.)
#print gamma, v/c
ra = np.deg2rad(ra)
dec = np.deg2rad(dec)
dangle = np.arccos(
np.cos(np.deg2rad(arr[1])) * np.cos(dec) *
np.cos(np.deg2rad(arr[0]) - ra) +
np.sin(np.deg2rad(arr[1])) * np.sin(dec))
#print np.rad2deg(np.min(dangle)), np.rad2deg(np.max(dangle))
tanphi = np.sin(dangle) / (gamma * (np.cos(dangle) - v / c))
rotor = rot.RotateCelestial2Native(lon=np.rad2deg(ra),
lat=np.rad2deg(dec),
lon_pole=5. * u.degree)
rotorback = rot.RotateNative2Celestial(lon=np.rad2deg(ra),
lat=np.rad2deg(dec),
lon_pole=5. * u.degree)
lon, lat = rotor(arr[0], arr[1])
#print np.rad2deg(dangle) + lat
#print np.rad2deg(dangle)
#print np.rad2deg(np.arctan(tanphi))
phi = np.rad2deg(np.arctan(tanphi))
phi = phi + (-1. * np.sign(phi) + 1.) * 90.
#print phi
#print dangle - np.arctan(tanphi)
diff = np.rad2deg(dangle) - phi
print diff
#latab = np.rad2deg(np.arctan(tanphi))
latab = lat - diff
#print (np.rad2deg(dangle) - np.rad2deg(np.arctan(tanphi)))#[0], lon[0], lat[0]
#print lat - latab
#print lat
cellon, cellat = rotorback(lon, latab)
return np.vstack((cellon, cellat))
decf = (dec[frame1:frame2]) latf = (lat[frame1+offset:frame2+offset]) lstf = lst[frame1+offset:frame2+offset] #Map parameters crpix = np.array([50,50]) crval = np.array([132.2, -42.9]) cdelt = np.array([-0.003, 0.003]) lonpole = 180. ''' Build a wcs for telescope coordinates rotating Celestial Sphere to native sphere using astropy routines and then using wcs module to build it ''' n2c = rotations.RotateCelestial2Native(lon=crval[0], lat=crval[1], lon_pole=lonpole) new_crval = n2c(crval[0],crval[1]) new_coordinates = n2c(raf*15, decf) w = wcs.WCS(naxis=2) w.wcs.crpix = crpix w.wcs.cdelt = cdelt #w.wcs.crval = new_crval w.wcs.crval = crval w.wcs.ctype = ["TLON-TAN", "TLAT-TAN"] coord = np.transpose(np.vstack((raf*15, decf))) #coord = np.transpose(np.array([new_coordinates[0], new_coordinates[1]])) px = w.all_world2pix(coord, 1) px2 = w.wcs.s2p(coord, 1)