Estimate UVW from image parameters

# the phase center PSF
self.phasePSF = phasePSF;
# Observed frequency
self.freq0 = freq0 or 1.;
# the compression in time
self.dtime = dtime or 1;
# the compression in frequency
self.dfreq = dfreq or 1;
# the resolution or the pixel size in radian
self.resolution = np.pi*(cellsize/3600.)/180.;
self.npix, n = phasePSF.shape
Fov = n*self.resolution
Delta_u, Delta_v = (1./Fov, 1./Fov)
u = np.linspace(-(n-1)/2*Delta_u,(n-1)/2*Delta_u,n)
v = np.linspace(-(n-1)/2*Delta_v,(n-1)/2*Delta_v,n)
uu,vv = np.meshgrid(u,v)
# angle of orientation
vv[vv==0]=1.e-9
angle = np.arctan(uu/vv)
#angle[uu==0]=1e-9
# uv distance in radian
self.uvd = np.sqrt(uu**2 + vv**2)
# angular velocity on one year
ang_velocity = 2.*np.pi/(3600.*24.)
self.du =ang_velocity*self.uvd*(-1*np.sin(angle))
self.dv =ang_velocity*self.uvd*np.cos(angle)
self.UVdomain = np.fft.fftshift(np.fft.fft2(self.phasePSF))
print ("**************************** here ************************************************")
self.liste=[]
self.cellsize = cellsize
self.npixDirty = npix