INFILE Input data file name. OUTNAME Output image name. OUTDISK 0.0 9.0 Output disk number. UVTAPER 0.0 Data tapering: (1) type, (2) width in cells to 0.5 OPTYPE Telescope type: 'PFOC' prime focus, 'SUBR' subreflector 'SURP' subreflector with reference pointing FACTOR 0.0 100.0 Magnification: 0 -> 13 OFFSET 0.0 100.0 Distance from prime focus to bottom subreflector 0->0.512 REFREQ 0.0 Reference frequency in GHz APARM Operating parameters. 1: Frequency (GHz). 2: Satellite elevation, deg. Use 0 for sidereal obj. 3: Antenna diameter, m. 4: Unpaneled diameter, m. (3,4) used to blank ant. aperture phase data. 5: Focal length, m. 6: Slope in SURP 0 -> 0.65 7: Disabled 8: Disabled 9: 10000 * Ref ant. + 100 * target ant. + IF#. 10: Stokes (RR=1, LL=2) (9) and (10) used only if INFILE is not of form 'AREA:FILE' CELLSIZE Cell size in asec for output image type 1-3. Resets BPARM(1) BPARM Data reduction parameters. 1: Required map size, meters or use CELLSIZE 2: No. of pixels on a side of the output map (power of 2, min=32, max=512). 0 => 128 3: Min. antenna scan angle Units: inverse sine(ang) 0 => all data used. 4: Max. antenna scan angle Units: inverse sine(ang) 0 => all data used. <0 => radial (min, max). 5: Amplitude scaling factor 0 => 1 6: Fourier transform sign 0 => -1 (VLA convention) 7: Minimum antenna aperture used for fit, in meters < 0 => circular min. 0 => set by APARM(4) 8: Maximum antenna aperture used for fit, in meters < 0 => Circular max. 0 => set by APARM(3) (7,8) used for focus and pointing calculations. 9: Correction control flags: read the HELP! 10: >0 => logarithmic ampl. .LE. 0 => linear ampl. default = linear CPARM Parameters for the gridding operation (see HELP). NORMALIZ -1.0 1.0 > 0 => normalize outputs 1 and 2 below DOVECT -1.0 1.0 > 0 write real/imaginary not amplitude/phase images DPARM Output maps, >0 => Save this. 1,2: Regridded amplitude and phase of the observed antenna beam pattern. 3: Weights used in the regridding procedure. 4,5: Derived amplitude and phase of the antenna illumination 6,7: Amplitude and phase of the point-spread func. 8: Focus model corrections 9: Surface deviation map. 10: Antenna power pattern and phase (See HELP!) VPARM Use this model don't fit 1. Constant offset degrees 2. Phase ramp in X deg/cell 3. Phase ramp in Y deg/cell 4. Feed/subreflector offset in X in mm 5. Subreflector/Feed offset in Y in mm 6. Subreflector/Feed offset in Z in mm (focus) 7. Subreflector X tilt deg 8. Subreflector Y tilt deg 9. Cassegrain feed offset in X mm 10. Cassegrain feed offset in Y mm 11. > 0 replace phase with model 12. > 0 Replace amp with average, value is clip level (all below set 0)

HOLOG Type: Task Use: HOLOG processes holography data. It reads visibility data from a file and Fourier transforms it to produce the grading in the aperture plane of the antenna. Up to nine different AIPS image files will be produced according to the options specified in DPARM. In the following description, (l,m) are the angular antenna offsets, while (u,v) are distances in the antenna aperture plane. The input data format is four free format ASCII encoded values per record: 1) Azimuth offset from source (degrees) or true l (if APARM(2) <= 0) 2) Elevation offset from source (degrees) or true m (if APARM(2) <= 0) 3) Amplitude (Volts or dB) or Real (Volts) 4) Phase (degrees) or Imaginary (Volts) Adverbs: INFILE......Input visibility file name in the form AREA:FILE, where AREA is a directory logical name or environment variable, and FILE is an operating system specific file name. If INFILE = 'ANT' or is blank, then INFILE will be set to 'FITS:HOLOnn-mmssii' where nn is the moving antenna number and mm is the reference antenna number (= 0 if more than one reference antenna is used), ss is the Stokes, and ii is the IF. If INFILE contains only a logical name, as INFILE = 'AREA:', then 'AREA:HOLOnn-mmssii' will be used. The values of nn, mm, ss, and ii come from APARMs (9) and (10). OUTNAME.....Output image name (12 characters). If the last 7 characters are blank, they are set to 'nn-mmss'. OUTDISK.....Output disk number. UVTAPER.....Tapering of data during the gridding process: (1) Type: 1 Gaussian, 2 Exponential, 3 Linear (2) Radius in cells for taper of 0.5. 0 => N/3. (Remember that the max radius of the data must be < N/2 just to avoid aliasing.) OPTYPE......The model used for removing the effects of primary focus offset. 'PFOC' = Prime Focus. 'SUBR' = Cassegrain system. 'SURP' = Cassegrain system with reference pointing - default SUBR FACTOR......The magnification. Used only if OPTYPE = 'SUBR', 'SURP' OFFSET......The distance between the prime focus and the bottom of the subreflector in meters. Otherwise known as c-a where 2c is the distance between the 2 hyperbolic foci and a is the distance between the y-axis intercept of the upper hyperboloid from the midpoint of the 2 foci in meters. 0 -> 0.522 appropriate for the VLA. Used only with tilt parameters to display tilts in degrees rather than physical offsets and only with subreflector OPCODEs. Operating parameters: all are required (NO defaults). REFREQ......Use this as the reference frequency in GHz. If 0, use the observing frequency found in the UVHOL output file (INFILE here). APARM(1)....Observing frequency (GHz). (ignored) APARM(2)....Satellite elevation, degrees. Set = -1. for VLA data (true l,m); set = +1. for sky az,el; set = actual elevation for true az,el APARM(3)....Antenna diameter, in meters. Used to blank antenna surface phase map before applying models. APARM(4)....Subreflector or unpaneled diameter, in meters. Used to blank antenna phase map before models are applied. APARM(5)....Focal length, in meters. This is used in correcting for the focus and feed offset, and in computing the surface deviation map. APARM(6)....In SURP only, the slope applied to "q". 0 -> 0.65 APARM(7-8)..Inoperative. APARM(9)....10000 * Reference antenna number + 100 * 2nd (moving) antenna number + IF number. Used only for default names (i.e., if INFILE = 'AREA:') APARM(10)...Stokes ID (1 - 4 => RR, LL, RL, LR). Used only for default names (i.e., if INFILE = 'AREA:') Data reduction control parameters. CELLSIZE....Cell size in asec for output image types 1, 2, and 3. If > 0, BPARM(1) is reset to Lambda / (CELLSIZ(1) * AS2RAD) BPARM(1)....Required map size, in meters. or use CELLSIZE BPARM(2)....Number of pixels on a side of the output map (power of 2, maximum 512). BPARM(3,4)..Range of |l| and |m| (antenna scan angles) to use for transform. Units are inverse sine(angle) BPARM(5)....Scaling factor for the input amplitudes. BPARM(6)....Fourier transform control. If negative, the phase read from the data file is negated. If the absolute value is 2, a direct Fourier transform will be done, otherwise, an FFT. BPARM(7,8)..Range of |x| and |y| used in correcting for pointing, focus, and feed offset. Negative values give (min, max) of r = SQRT(u*u + v*v). See also BPARM(9). BPARM(9)....Decimal encoded control parameters 1: If set, apply the subreflector tilt model. 10: Turn off phase slope model (pointing). 100: Inhibit local phase ambiguity correction in the antenna aperture (V_PHA) plane. 1000: Turn off all model calculations. 2000: Turn off subreflector offset model. 4000: Turn off focus (z) model. 8000: Turn on Cassegrain feed offset model BPARM(10)...Switch for logarithmic or linear data >= 0 for logarithmic data (as for PKS) < 0 for linear data (for the VLA). Regridding parameters. CPARM(1)....Type of interpolation to apply in gridding 'l'. 1: Pillbox, (don't use for regularly sampled data) 2: Exponential, 3: Sinc, 4: Sinc*Exponential, 5: Spheroidal (default). NEGATE to obtain natural weighting. (default = uniform) CPARM(2)....Support radius in u, in cells. CPARM(3-5)..Parameters defining the interpolation function in 'l'. Do HELP UVnTYPE for n=1,2,3,4,5. CPARM(6-10).Corresponding parameters for 'm'. Output option flags. NORMALIZ....> 0 => amplitude and phase will be normalized, else no normalization of amplitude and phase is done. DOVECT......> 0 -> write real and imaginary rather than amplitude and phase on DPARM(1,2) The particular map will be stored if the associated DPARM is > zero. If all are <= 0, DPARM(4,5) will both be set to 1. AIPS task PANEL wants (4) for the mask and (9) for the deviations. DPARM(1,2)..Regridded amplitude and phase of the observed antenna beam voltage pattern (A_AMP, A_PHA). DPARM(3)....Weights used in the regridding procedure (WGT) - includes the weights for uniform (vs natural) weighting. DPARM(4,5)..Derived amplitude and phase of the illumination of the antenna aperture (V_AMP, V_PHA). The focus model, if requested, will be removed from the phase image. DPARM(6,7)..Amplitude and phase of the point-spread function. This indicates the blurring in the derived grading map (P_AMP, P_PHA). DPARM(8)....Map of the phase corrections removed by the focus model (MODEL). DPARM(9)....Map of the surface deviations of the antenna (V_DEV). Units are in meters. The focus offset model, if requested, will be removed. DPARM(10)...The interpolated antenna power pattern (A_PWR). Set it = to the desired interpolation factor, with anything >0 and < 2 => 2. Must be a power of 2 <= 2048 / NPIX, where NPIX = BPARM(2). The phase image (A_PHS) is also written out. Compute a model rather than fitting one: If any of VPARM(1) through VPARM(8) is not zero, then a model image is computed from the parameters in VPARM rather than being fit to the data in INFILE. Different models are computed for the 3 values of OPTYPE. VPARM(1)....Constant phase offset in degrees VPARM(2)....Phase ramp in X in degrees/cell - equivalent to a pointing error in X in arc minutes VPARM(3)....Phase ramp in Y in degrees/cel - equivalent to a pointing error in Y in arc minutes VPARM(4)....Feed offset in X in mm for PFOC Subreflector offset in X in mm for SUBR, SURP VPARM(5)....Feed offset in Y in mm for PFOC Subreflector offset in Y in mm for SUBR, SURP VPARM(6)....Feed offset in Z in mm for PFOC Subreflector offset in Z in mm for SUBR, SURP VPARM(7)....Subreflector tilt in X in degrees VPARM(8)....Subreflector tilt in Y in degrees VPARM(9)....Cassegrain feed offset in X in mm VPARM(10)...Cassegrain feed offset in Y in mm VPARM(11)...> 0 => replace phase with model VPARM(12)...> 0 => replace amplitude with average amplitude if amplitude > VPARM(12), else set amplitude to 0. The amplitude is a weighting function in the the determination of rms, forward gain, and beam pattern.