ism3d.uvhelper.ft

Functions

advise_header	create a header template for discreating cloudlet model before uv sampling
advise_imsize	Compute the recommended image size given the (u, v) locations. Typical call signature:: nxy, dxy = advise_imsize(u, v, PB=0, f_min=5., f_max=2.5, verbose=False) :Parameters: * u (array_like, float) – u coordinate of the visibility points where the FT has to be sampled. units: wavelength * v (array_like, float) – v coordinate of the visibility points where the FT has to be sampled. The length of v must be equal to the length of u. units: wavelength * PB (float, optional) – Primary beam of the antenna, e.g. 1.22*wavelength/Diameter for an idealized antenna with uniform illumination. units: rad * f_min (float) – Size of the field of view covered by the (u, v) plane grid w.r.t. the field of view covered by the image. Recommended to be larger than 3 for better results. units: pure number * f_max (float) – Nyquist rate: numerical factor that ensures the Nyquist criterion is satisfied when sampling the synthetic visibilities at the specified (u, v) locations. Must be larger than 2. The maximum (u, v)-distance covered is f_max times the maximum (u, v)-distance of the observed visibilities. units: pure number * verbose (bool, optional) – If True, prints information on the criteria to be fulfilled by nxy and dxy.
invert_ft	use nufft to create dirty cube from visibility uu: in meter (vector, nrecord vv: in meter (vector, nrecord) wv: in meter (vector, nchannel) psize: Quality wt: apply wt when doing invert (essentialy nature weighting) only works when bychannle=true bychannel: False ignore the wavelength changing effect on uvw True: uu/vv will be calculated channel by channel sortbyfreq: make sure the output cube is increasing by frequency (even chanel-freq is decreasing) this make it easy to compare with the tclean results whihc is always mono-increasing in freq output (nx,ny,nz)
make_psf