INNAME UV data (name). INCLASS UV data (class). INSEQ 0.0 9999.0 UV data (seq. #). 0 => high INDISK Disk unit #. 0 => any OUTNAME Image data (name). OUTCLASS Image data (class). OUTSEQ 0.0 9999.0 Image data (seq. #). 0=>high OUTDISK Disk unit #. 0 => any SRCNAME Source list TIMERANG Time range to list STOKES Stokes type to list. SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select. BIF 0.0 100.0 Lowest IF number 0=1 EIF 0.0 100.0 Highest IF number BCHAN 0.0 2048.0 Low channel number 0=>1 ECHAN 0.0 2048.0 High channel number ANTENNAS Antennas to list BASELINE Baselines with ANTENNAS UVRANGE 0.0 UV range in kilolambda SUBARRAY 0.0 1000.0 Subarray, 0=>1 Cal. info for input: DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CAL (CL or SN) table to apply DOPOL -1.0 10.0 If >0 correct polarization. PDVER PD table to apply (DOPOL>0) BLVER BL table to apply. FLAGVER Flag table version DOBAND -1.0 10.0 If >0 apply bandpass cal. Method used depends on value of DOBAND (see HELP file). BPVER Bandpass table version SMOOTH Smoothing function. See HELP SMOOTH for details. DPARM Control info: (1) 0=amp, 1=phase, 2=rms, 3=rms/mean, 4=real part, 5=imaginary, 6=beam, 7=count, 8=1.0 if sampled (2) 0=vec avg, 1=scalar (3) >0 = baseline as ant pair for B as x-axis only (4) >0 => divide by source IPOL flux (5) x-axis interval: is B for TB and is ignored, else is the 2nd sort parameter NO default. Units: seconds, wavelengths **** NO DEFAULT **** (6) y-axis interval: T for TB first sort parameter **** NO DEFAULT **** (7) > 0 => do NOT divide by the summed weights (8) > 0 -> use XTYPE, YTYPE and interpolate to grid (9) > 0 -> empty cells set to zero, else blanked (10) Use data weight to the power 1/DPARM(10) IMSIZE 1.0 18384.0 Output image size in x,y x ignored if B NCHAV Number of channels to include in each plane CHINC Increment between start channels of each plane SORT Desired uv image axes DOROBUST -1.0 1.0 > 0 use ROBUST weighting ROBUST -5.0 5.0 Brigg's robustness parameter XTYPE 0. 20. Conv. function type in x default spheroidal New round types - SEE HELP YTYPE 0. 20. Conv. function type in y default spheroidal XPARM Conv. function parms for x YPARM Conv. function parms for y SCALR3 -1. 1. > 0 => do not grid Hermitian BADDISK Disk to avoid for scratch.

UVIMG Type: Task Use: Grids UV data of the selected type to form an image. UVIMG will work on single- and multi-source files in any sort order. It grids the data by the SORT parameters with the 2nd (faster) parameter on the x axis and the 1st (slower) parameter on the y axis. All samples falling into a cell are averaged by vector or scalar averaging. Each included channel and IF may be gridded to a separate plane of the output 3- or 4-dimensional image. Spectral channels, but not IFs, may be "averaged" together (where u,v,w are adjusted for each frequency before gridding). Note that it is usually essential to specify DPARM(5) and DPARM(6) since an increment of 1 is normally not useful. The task attempts to grid the data sample and its Hermitian except when the two axes are normal baseline number (DPARM(3) <= 0) and/or baseline length and/or time. In these three cases, the two would land on top of each other and, at least for phase, would be destructive. Note that both samples may not land on the grid, as in axes X, Y, Z, and M. DPARM(8) was added to signal your intention to use convolving functions when interpolating to the grid. XTYPE and YTYPE are convolve a sample potentially to multiple cells in the UVIMG plane. Since this operation is not normally desired, the task now requires you to set this additional adverb before it will use XTYPE, YTYPE, XPARM, and YPARM. Adverbs: INNAME.....UV file name (name). Standard defaults. INCLASS....UV file name (class). Standard defaults. INSEQ......UV file name (seq. #). 0 => highest. INDISK.....Disk unit #. 0 => any. OUTNAME....Image file name (name). Standard defaults. OUTCLASS...Image file name (class). Standard defaults. OUTSEQ.....Image file name (seq. #). 0 => highest. OUTDISK....Output disk unit #. Standard defaults. SRCNAME....Source name to be gridded. Must specify if input is a multi-source data set, otherwise all sources are included. TIMERANG...Time range of the data to be gridded. In order: Start day, hour, min., sec, end day, hour, min., sec. in days relative to reference date. STOKES.....The desired Stokes type of the gridded data ' ' => 'I'. Only 1 Stokes type may be used: I, Q, U, V, RR, LL, RL, LR, VV, HH, VH, HV SELBAND....Bandwidth of data to be selected. If more than one IF is present SELBAND is the width of the first IF required. Units = kHz, 0=> all SELFREQ....Frequency of data to be selected. If more than one IF is present SELFREQ is the frequency of the first IF required. Units = MHz, 0=> all FREQID.....Frequency identifier to select (you may determine which is applicable from the OPTYPE='SCAN' listing produced by LISTR). If either SELBAND or SELFREQ are set their values overide that of FREQID, however setting SELBAND and SELFREQ may occasionally result in an ambiguity, in which case the task will request that you use FREQID. BIF........Lowest IF to grid. IF will be axis 4. ************************************************** NOTE to VLA users: IF=1 corresponds to the VLA AC ifpairs and IF=2 corresponds to the BD ifpairs. ************************************************** EIF........Highest IF to grid. 0 => highest. BCHAN......First channel to grid. 0 => 1. ECHAN......Last channel to grid. 0 => highest. ANTENNAS...A list of the antennas to grid. If any number is negative then all antennas listed are NOT desired and all others are. All 0 => grid all. BASELINE...Baselines are specified for the LIST option using BASELINE. Eg. baselines 1-6,1-8, 2-6 and 2-8 use ANTENNAS=1,2; BASELINE=6,8. UVRANGE....Range of projected spacings to be gridded in 1000's of wavelengths. 0 => 1, 1.E10 SUBARRAY...Subarray number to grid. 0=>1. DOCALIB....If true (>0), calibrate the data using information in the specified Cal (CL) table for multi-source or SN table for single-source data. Also calibrate the weights unless DOCALIB > 99 (use this for old non-physical weights). MUST be false for data not in T* order. GAINUSE....Version number of the Cal. table to apply to the data if DOCALIB=1. Refers to a CL table for multisource data of an SN table for single source. 0 => highest. DOPOL......If > 0 then correct data for instrumental polarization as represented in the AN or PD table. This correction is only useful if PCAL has been run or feed polarization parameters have been otherwise obtained. See HELP DOPOL for available correction modes: 1 is normal, 2 and 3 are for VLBI. 1-3 use a PD table if available; 6, 7, 8 are the same but use the AN (continuum solution) even if a PD table is present. PDVER......PD table to apply if PCAL was run with SPECTRAL true and 0 < DOPOL < 6. <= 0 => highest. BLVER......Version number of the baseline based calibration (BL) table to appply. <0 => apply no BL table, 0 => highest. FLAGVER....Specifies the version of the flagging table to be applied. 0 => highest numbered table. <0 => no flagging to be applied. DOBAND.....If true (>0) then correct the data for the shape of the antenna bandpasses using the BP table specified by BPVER. The correction has five modes: (a) if DOBAND=1 all entries for an antenna in the table are averaged together before correcting the data. (b) if DOBAND=2 the entry nearest in time (including solution weights) is used to correct the data. (c) if DOBAND=3 the table entries are interpolated in time (using solution weights) and the data are then corrected. (d) if DOBAND=4 the entry nearest in time (ignoring solution weights) is used to correct the data. (e) if DOBAND=5 the table entries are interpolated in time (ignoring solution weights) and the data are then corrected. BPVER......Specifies the version of the BP table to be applied. <0 => no BP correction. SMOOTH.....Specifies the type of spectral smoothing to be applied to a uv database . The default is not to apply any smoothing. The elements of SMOOTH are as follows: SMOOTH(1) = type of smoothing to apply: 0 => no smoothing To smooth before applying bandpass calibration 1 => Hanning, 2 => Gaussian, 3 => Boxcar, 4 => Sinc To smooth after applying bandpass calibration 5 => Hanning, 6 => Gaussian, 7 => Boxcar, 8 => Sinc SMOOTH(2) = the "diameter" of the function, i.e. width between first nulls of Hanning triangle and sinc function, FWHM of Gaussian, width of Boxcar. Defaults (if < 0.1) are 4, 2, 2 and 3 channels for SMOOTH(1) = 1 - 4 and 5 - 8, resp. SMOOTH(3) = the diameter over which the convolving function has value - in channels. Defaults: 1,3,1,4 times SMOOTH(2) used when input SMOOTH(3) < net SMOOTH(2). DPARM......Control info: (1) controls the type of information to be gridded: 0 => amplitude, 1 => phase, 2 => RMS of amplitude 3 => RMS of amplitude / mean of amplitude 4 => real part of visibility 5 => imaginary part of visibility 6 => "beam" (Vis changed to 1,0) 7 => count of samples 8 => 1.0 in sampled cells (2) controls the type of averaging: <= 0 => vector average, > 0 => scalar averaging (amplitude only). (3) controls how "baseline number" is computed <= 0 => normal baselines (1-1,1-2, 1-3, ... 1-N, 2-2,2-3, 2-4, ... 2-N, 3-3,3-4, ...) > 0 => as antenna pair gridding each sample twice (1-1,1-2, 1-3, ... 1-N, 2-1, 2-2, 2-3, ... 2-N, 3-1, 3-2, ... 3-N, ...) (4) <= 0 => grid amplitudes as found in data set > 0 => divide amplitudes by source flux (5) x-AXIS interval: 0 -> 1 except 1.0 is forced for B type axis. Units are wavelengths for U, V, W, X, Y, Z, and M sort orders and seconds for T. NO SENSIBLE DEFAULT (6) Y-axis interval: 0 -> 1 except 1.0 is forced for B type axis. Units are wavelengths for U, V, W, X, Y, Z, and M sort orders and seconds for T. NO SENSIBLE DEFAULT (7) > 0 => do NOT divide by the count (or sum of convolution weights) for DPARM(1) types 0 through 5. Makes image a convolution such as done by IMAGR, UVMAP, et al. <= 0 => do divide by the sum of counts or convolution function weights in each cell. Makes image an interpolation of the data. (8) > 0 => use XTYPE, YTYPE, XPARM, and YPARM to convolve to the grid. <= 0 => put each sample at the nearest grid cell. (9) > 0 => empty cells are set to 0 - if you plan to FFT the image you must set DPARM(9) > 0. <= 0 => emptry cells are set to magic blanks except for DPARM(1) = 6 and 7 (10) > 0 => use data weight when gridding to the power 1/DPARM(10) NOTE WELL: data weights are ignored if DPARM(10) is not set! IMSIZE.....X,Y output image size, no sensible default except for B type axis which will be forced, NCHAV......NCHAV is the number of channels to be averaged together in in the gridding process. 0 => 1. If this value is less than the total number of spectral channels, then the output image will have multiple planes of averaged channels. Note that all spectral planes will include data from NCHAV input channels so the actual ECHAN used may be less than that specified (or in the data set). To make a single plane image from multiple IFs and multiple spectral channels set NCHAV >= (EIF-BIF+1) * (ECHAN-BCHAN+1) CHINC......Number of input channels to skip between images. 0 => 1 The i'th spectral plane includes input channels BCHAN + (i-1)*CHINC through MIN (ECHAN, BCHAN + (i-1)*CHINC + NCHAV - 1). CHINC is ignored if NCHAV >= ECHAN-BCHAN+1. SORT.......The YX axis types are specified by two keys which are characters in the adverb SORT. The legal keys are: B => baseline number T => time order U => u spatial freq. coordinate V => v spatial freq. coordinate W => w spatial freq. coordinate R => baseline length. P => baseline position angle. X => descending ABS(u) Y => descending ABS(v) Z => ascending ABS(u) M => ascending ABS(v) Any blank character is replaced with the corresponding character in the UV data base sort order. For SORT='UV' to be fed to FFT, use DPARM(5) = -x and DPARM(6) = +x (x > 0). DOROBUST...> 0 => Do uniform -> natural weighting If > 0, then DPARM(7) is set to 1 so that weighting is done by this process rather than normalizing by counts or sum of weights. Does not apply to DPARM(1) = 6 or 7. Robust weighting is also not done for SORT='TB' with data already sorted in TB order. ROBUST.....Brigg's robustmess parameter. -4 uniform, 4 natural See help file for details. If XPARM(8) > 0, then XTYPE......Convolution function type in X-direction 0 -> none - take nearest pixel, 1=Pillbox, 2=exponential, 3=Sinc, 4=Exp*Sinc, 5=Spheroidal, 6=Exp*BESSJ1(x)/x > 6 (& < 11) -> 5. 11 - 16 => circular functions in radius corresponding to 1 - 6 types above; YTYPE, YPARM are ignored. See HELP UV1TYPE through HELP UV6TYPE for details. YTYPE......Convolution function type in Y-direction XPARM......Array containing parameters for XTYPE. See HELP UVnTYPE when n=convolution type. YPARM......Array containing parameters for YTYPE. BADDISK....Disk numbers to avoid for scratch files. Scratch files may be created by the sorting routines if calibration or flagging is applied.