; WHATSNEW ;--------------------------------------------------------------- ;! lists changes and new code in the last several AIPS releases ;# INFORMATION GENERAL ;----------------------------------------------------------------------- ;; Copyright (C) 1996-2000 ;; Associated Universities, Inc. Washington DC, USA.; E Greisen ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- WHATSNEW LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC ---------------------------------------------------------------- **************************************************************** WHATSNEW in 31DEC99 AIPS AIPS for the Ages last edited 29 November 2000 31DEC99 was a new form of AIPS (non)-release. It was supposed to remain always under development and user sites were expected to install it and then stay current via a "midnight job" update procedure. But the sites have been resistant and we are now faced with "which date 31DEC99 do you have". So we are going back to, now annual, releases, beginning with 31DEC00. Sites wishing to have code less than 1 year old will still need to fetch the current TST code - soon to be 31DEC01 - and then run the mnj update procedure to stay current. There will soon be an AIPSLetter for 31DEC00, released sometime in December 2000 and there was sn AIPSLetter for (then) 31DEC99 released around April 1, 2000. Get to these via the WWW: http://www.cv.nrao.edu/aips or find the files in $AIPSPUBL/LET00*.PS. **************************************************************** Additions in the April-November period: 1. IMAGR offers the option to remake all fields every n'th cycle in the "OVERLAP 2" mode by setting OVERLAP to n (> 2). You are allowed to have no Clean boxes in a field. The task failed to taper data when natural weighting was requested. 2. A bug in the Clean Component model division/subtraction routines had a small error in the frequency scaling of U and V. This affected the ability to model and remove distant interfering sources. Gridded subtraction was made faster in large cases and a bug preventing the SMODEL option from functioning was corrected. 3. FACES is a new task to make a data model from the NVSS or WENSS catalogs, complete with images and CC files. This task, plus, SETFC, PBCOR and PATGN have new beam pattern parameters found by Rick Perley using the new fitting task PBEAM. 4. HGEOM and OHGEO have changed inputs to allow more control of the output reference pixel. Read the help files carefully. 5. FILLM now has the DOWEIGHT adverb to control which weighting scheme is used. FILLM will stop on end of tape. Errors recognizing when sources and modes have changed were fixed as was an error in correcting for nominal sensitivities in solar mode. 6. CALIB and FRING could make errors in handling fast switching data, leading to noisy solutions interspersed among good ones. 7. There is a suite of procedures intended to simplify VLBA data reduction. Type HELP VLBAUTIL for information. 8. MATCH is a new task to renumber sources, antennas, and FQids so that one data set will match another. 9. FXPOL was re-written to handle much more complicated cases. It now writes a new output data set in all cases. 10. FLGIT handles the cutoff levels improperly, causing it to delete more data than expected. 11. A new verb - ~ (the tilde sign) - was added to allow setting a scalar adverb (e.g. RASHIFT(8)) and beyond to list of values. This solves the line-length limit problem in AIPS when setting array values. 12. XAS, the TV display, now works on 24-bit as well as 32-bit true color displays. 13. UVPLT can plot weights, elevation, hour angle, etc and uses REFANT to control which antenna they refer to. 14. TVLABEL now supports the GRCHAN adverb. 15. Y2K is a new test suite for aips tasks and larger computers. **************************************************************** Additions in the 21-Feb to 18-Apr, 2000 period: 1. DBCON now does correct frequency-dependent phase shifts in all cases (it did most right before) and the help file no longer claims otherwise. FQ tables are examined and the FQ numbers are changed as needed under control of the FQTOL adverb. 2. SPFLG now displays all channels for all IFs on the horizontal axis. This means that you no longer have to select IFs one at a time. 3. UJOIN now correctly flags a whole spectrum if any channels (in that Stokes) are flagged when requested to do so. This request is now the default. Additional run-time displays and improved help-file explanations were also added. 4. FILLM now has the recommended option (CPARM(2)=8) of setting the data weights using the nominal sensitivity of each antenna/IF already used by the on-line system to scale the visibilities. All calibration application tasks now have the option (DOCAL=2) of applying the calibration to the weights, keeping these new weights proportional to 1/sigma**2 in Jy. 5. PUTTHEAD may now create new table header keywords as well as changing the values of pre-existing ones. 6. CHANSEL (and NBOXES/BOX) have been replaced wherever they were used to specify channel averaging ranges or baseline fitting ranges. The new adverb ICHANSEL(4,20) allows the specification of IF number in ICHANSEL(4,i), with 0 => all IFs. Tasks affected: AVSPC, BPASS, CPASS, PHSRF, SPLIT, SPLAT, UVLIN, UVLSF, UVMLN, FLGIT, UVLSD. **************************************************************** Imaging: 1. IMAGR: a. The output names of all imaging tasks were changed to be decimal rather than extended hex and to be 1-based rather than 0 relative. The are now xCLnnn, xIMnnn, xBMnnn where x is the Stokes and nnn = 001-512. Both the new and the old names are supported by all CC model using tasks (e.g. CALIB, UVSUB, ...) b. Added option ALLOKAY to allow IMAGR to restart without recomputing beam images and without recomputing residual data, if the user says that all is okay. c. Added the ability to image and Clean with both point and Gaussian component models. "Simultaneous" Cleans with multiple resolutions may help with the corrugation and extended source problems traditional in Hogbom Cleans. d. A bug affecting multi-field gridding when the first field was done in memory but later fields required disk-based gridding was corrected. e. A bug affecting FILEBOX operations on boxes outside the current field of view was corrected. f. A bug causing IMAGR to use the wrong scratch files for the gridded subtraction was corrected. This would appear as an attempt to read beyond the end of file when the beam is the same size as the image. Otherwise, it was probably negligable. g. The maximum number of Clean boxes per field was changed so that up to 2048 may be used so long as the number of fields is <= 64. The maximum number decreases to 256 for 512 fields. 2. SCIMG - a new task which is a multi-field version of SCMAP to do iterative self-cal and imaging. 3. MAPPR is a new procedure which simplifies the inputs to IMAGR for imaging a single field WITHOUT calibration, wide-field options, multiple resolutions, and the SDI method. Visibility data: 1. EDITR, EDITA, SNEDT : a The new CROWDED adverb controls whether multiple IFs and/or polarizations may appear on the plots and be edited at the same time. b. They now accept the REASON adverb for an initial value. c They use certain fixed plot scales and mode settings when starting in expert mode. d. They support scaling amplitude from 0 to max. e. They do a new TV option to display/edit the NEXT CORRELATOR. f. To save time, difference data are computed only when needed. g. The ANTUSE adverb is used to select which data are displayed initially. 2. SPFLG has a changed and more general meaning to the SWITCH ALL-BL FLAG control It now displays all channels for all IFs on the horizontal axis. This means that you no longer have to select IFs one at a time. 3. FILLM now has the recommended option (CPARM(2)=8) of setting the data weights using the nominal sensitivity of each antenna/IF already used by the on-line system to scale the visibilities. All calibration application tasks now have the option (DOCAL=2) of applying the calibration to the weights, keeping these new weights proportional to 1/sigma**2 in Jy. Even VLB tasks must explicitly specify DOCAL=2 to get weight calibration which used to be done on DOCAL=1 in FRING and a couple other VLBI tasks. 4. CHANSEL (and NBOXES/BOX) have been replaced wherever they were used to specify channel averaging ranges or baseline fitting ranges. The new adverb ICHANSEL(4,20) allows the specification of IF number in ICHANSEL(4,i), with 0 => all IFs. Tasks affected: AVSPC, BPASS, CPASS, PHSRF, SPLIT, SPLAT, UVLIN, UVLSF, UVMLN, FLGIT, UVLSD. 5. UVCOP did not do the proper time correction when copying a single subarray from a multi-array data set. It subtracted 5 days too many. 6. DBCON now does correct frequency-dependent phase shifts in all cases (it did most right before) and the help file no longer claims otherwise. FQ tables are examined and the FQ numbers are changed as needed under control of the FQTOL adverb. 7. SPLAT was changed to make a single-source output file properly when only one source is selected. 8. UJOIN now correctly flags a whole spectrum if any channels (in that Stokes) are flagged when requested to do so. This request is now the default. Additional run-time displays and improved help-file explanations were also added. 9. UVFIX was improved to shift positions correctly for spectral-line data and to handle astrometric matters more correctly. 10. CONFI has new options to control/limit the configurations being optimized. VLBI-specific issues: 1. FRING and KRING now allow the data modeling routines to use gridded model division under user direction (CMETHOD). 2. CALIB, FRING, KRING had problems re-referencing the phases when delays and rates are present. Display: 1. Tick marks are now plotted enough so that some measure of the scale is always visible. 2. VPLOT can now plot various types of data while time averaging. 3. FGPLT is a new task to display what baselines are flagged as a function of time. Try it. 4. TVSLICE, TVASLICE, and other new verbs were written to plot slices and models on the TV and to allow setting of fit parameters. The xterm emulation of Tektronix does not read cursors reliably. The old TVSLICE used to set the ends of a slice was replaced with SETSLICE. General: 1. New adverbs BPRINT, EPRINT, NPRINT, NPLOTS replaced over-used adverbs BCOUNT, ECOUNT, NCOUNT et al. in a number of tasks. 2. TBIN had problems with flagged table rows corrected. 3. PUTTHEAD may now create new table header keywords as well as changing the values of pre-existing ones. 4. Single dish tasks: BSTST has an added Clean option, BSCLN is a new beam-switched deconvolution task, BSMOD no longer requires input BS data. OTFBS now writes a TY table. 5. All CookBook chapters have been updated. Going AIPS was made available from the WWW pages. **************************************************************** **************************************************************** WHATSNEW in 15OCT99 AIPS (added 3 January 2000) AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET99B.PS **************************************************************** Imaging: 1. SETFC is a new task to compute field centers to cover the central portion of a large filed to be imaged and to find strong interfering sources from the NVSS and provide fields to image them as well. The output may be read directly by IMAGR. 2. IMAGR has several new options: a. The Clean method may be instructed to switch from the familiar Clark (Schwab/Cotton) method of finding components to the Steer-Dewdney-Ito method. This is appropriate when the residual image has large areas of nearly constant brightness. b. The ability to filter out "isolated weak" components from the Clean solution has been added. It may be used to eliminate areas of negative net component flux as well. c. Up to 512 fields are now allowed (and supported by all CC model using tasks). Field parameters for fields > 64 must be entered with the BOXFILE option. d. The meaning of the shift parameters was changed from shifts in -SIN projection to "simple" shifts to support large angles: RASHIFT = (Ra-Ra_0) * cos (Dec_0) and DECSHIFT = Dec - Dec_0. e. The work file is now deleted unless its name was specified. f. A TV option to control which field is cleaned next in OVERLAP=2 mode was added when the task is run with DOWAIT true of NFIELD>64 (i.e. interactively). g. The selection of which field to Clean next was improved. Plotting: 3. PLOTR - new task to plot a set of points read in from a text file. 4. Print tasks with 0 < DOCRT <= 72 will now use the actual width of the xterm window. 5. FUNCTYPE = 'SQ' (square root) was added to TVLOD and others. It is a good compromise between linear and log. 6. LWPLA can now do multiple plot files in one execution including writing multi-page PostScript files. 7. SNPLT can now plot multiple polarizations and/or IFs on the same plot or on separate plots. Interferometer and VLB data: 8. CLIPM is a new task to apply CLIP-like flagging to multi-source files, writing flag table entries. It and CLIP were given an option to flag the whole spectrum if more than a user-set number of individual channels are clipped. 9. The graphical editing tasks (EDITR, EDITA, SNEDT) were given the option to start in "expert" mode. The handling of times, previous flags, and the new FLAG QUICKLY function were fixed. 10. The use of CC data models was extended to allow up to 512 fields. The adverb FLUX was added to all such tasks to control the lowest (absolute value) component flux to be used in the model. The stop at first negative option, always present, was documented although it is not recommended. 11. FRING was corrected in its exhaustive baseline search options controlled by DOFIT and APARM(9). Its memory allocation when BCHAN/ECHAN were specified was also corrected. 12. KRING had its inputs simplified and the least-squares stages was replaced so that the SNRs found at all stages now agree. 13. FITLD now assigns data weights proportional to integration time. General and misc 14. DEFAULT is a new pseudo-verb to initialize only the adverbs applying to taskname. 15. VPUT/VGET allow the user additional TPUT/TGET-like files for saving task-specific parameters. VGINDEX will list the contents. 16. EXTAB is a new task to export AIPS table data for use in spreadsheets, databases, and other packages such as IDL. 17. XTRAN was changed to allow a "correct the header only" output mode and was corrected to do regridding correctly. 18. Single dish tasks: OTFUV was corrected to support AIPS' maximum number of channels (16384). BSGRD now allows the user to specify both of the gridding functions used. New task BSMOD allows simulation of beam-switched data with various errors. Bug fixes: 19. FITAB followed by re-loading and then FITTP could produce a nearly unreadable FITS file. The reading tasks were given an option to try to get around the bug and the writing tasks were changed to avoid it in future, 20. UVCOP failed to copy the correct data when both BIF > 1 and BCHAN/ECHAN selections were used and the frequency axis preceded the IF axis. 21. SPLAT and UVAVG were corrected to handle arbitrary random parameters in a general and more correct way. **************************************************************** **************************************************************** WHATSNEW in 15APR99 AIPS AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET99A.PS **************************************************************** VLB matters: 1. FITLD for VLB: a. New proc MERGECAL to merge redundant information created when calibration transfer data are concatenated. b. Corrected handling of BIF, EIF, BCHAN, ECHAN which were honored even if crazy (e.g. BIF of 3 in a 2-IF data set). c. Corrected handling of input tables to conform to new standards for the contents of these tables and to allow some older variations. Also changed to allow, with warnings, data out of time order. 2. CVEL - new option to control whether Hanning smoothing is used. This is a good idea if there are narrow lines. Otherwise, the shifting will produce ringing in the spectrum. 3. Fringe fitting: a. Corrected bug that kept FRING from looping correctly over subarrays and a bug that caused it to die when rate-only solutions failed. b. MBDLY now has FREQID and SUBARRAY adverbs, allowing more than the first of each to be used. c. KRING copies multi-band delays properly to all IFs. It uses a new scheme for computing SNRs detailed in AIPS Memo 101. KRING has been extensively tested using a new test data set created by DTSIM and compared with FRING. KRING runs faster in many cases, uses less memory, is able to handle larger problems then FRING. MBDLY frequently does not converge on correct answers. General uv data and calibration: 4. Calibration errors found: a. Since 1992, old calibrations were carried forward rather than being replaced by failed solutions (with the output data blanked). b. Faraday rotation corrections were not initialized properly. c. Calibration was not updated often enough for good antennas when some antennas had large gaps between solutions (1998-08-12 through 1998-10-17). d. Dispersive delay corrections are now done of there are non-zero values in the DISP 1 column of the CL table. e. QUAL and CALCODE are now used to select a list of sources some of which are selected or de-selected with the SOURCES adverb. f. 1.0 is no longer subtracted from autocorrelation data when bandpass calibration is applied. g. Calibration was not interpolated when the calibration values were updated unless the time also changed by "enough"; changed to force an update. h. BPASS failed to get the right solution for the second polarization when the first was fully flagged. 5. FITAB - new task to replace FITTP gradually. It can write more compressible image FITS files by allowing the user to control the quantization (scaling to integer form). It writes uv data in binary tables forms, optionally writing them as compressed data (like on disk) and in pieces. The former saves space while the latter provides better recovery from media error (e.g. parity, end-of-tape, etc.) Older FITS readers can read the images produced, but cannot read the uv data tables form. Please try FITAB, but not when you are taking the output to 15OCT98 or older AIPS versions or to packages such as difmap. 15APR99 versions of PRTTP, UVLOD, and FITLD can handle the new table format and PRTTP can now report on disk files. 6. TECOR - new task to perform ionospheric Faraday rotation and dispersive delay corrections using maps of the free electron content of the ionosphere in standard IONEX format. 7. CLCOR - The source position correction had its parameters changed. 8. FLGIT - Changed meaning of APARM(4 and 5), changed FLAGVER defaults, improved displays. Added option to flag on excess Vpol. 9. PRTUV - new adverbs were added to allow the user to specify scaling parameters so that the task does not have to spend time determining them. 10. ACFIT - was corrected to handle any size of input problem, to write correct REFANTs to the output, and to count output samples correctly. 11. UVCOP now does a better job of deleting flagged data when IF or channel selection is being done. 12. UVCON - new task to generate a uv database for an array configuration specified by the user. 13. SPLIT - had a bizarre ability to destroy SU (source tables). 14. UVHOL - is a new task to display and process holography data. These functions were removed from PRTUV. Imaging: 15. IMAGR - a. Changed to finish a full major cycle even if NITER is exceeded. b. Corrected bug in doing primary beam correction for multiple fields and fixed it to handle coordinates correctly even for 3D imaging. c. IMAGR, REBOX, and FILEBOX can now display boxes which are not completely on the visible TV area and revise only those that are fully visible. d. OVERLAP 2 is very useful and is now allowed without requiring DO3D to be true. This mode uses a modified scheme for selecting the next field to Clean which will avoid the Cleaning of noise fields to some extent. e. The gridded subtraction of Clean components has had an error for a very long time. The W term was not handled correctly when the first channel to be subtracted was not at the reference frequency. Using BIF > 1 or the primary beam correction could cause significant degradation in the quality of the subtraction in some cases. f. OBOXFILE is a new option to write out the Clean boxes set interactively in IMAGR and SCMAP. g. Gridding bugs due to gaps in |u| in the data distribution, particularly around 0, were corrected. h. Frequency offsets in the source table were previously ignored in setting the image scaling. 16. Images may now be up to 16384 on a side, a parameter which should be honored throughout AIPS. 17. FLATN - has another adverb to delete pixels around the edge of each input image. Changed it to use windows to speed up the operation. General matters: 18. TAPES - new verb to display what tapes are available on the local or on a remote host. It will even try to go to a remote TPMON over the Internet to get this information if it is not available locally! (Of course, it works only to >= 15APR99 sites.) 19. The use of INTEGER*2 was reduced in AIPS to the minimum possible since it is a source of compiler error (e.g. the newer egcs compiler versions). This caused major problems in FITTP on Linux systems. 20. XAS no longer has a small uninitialized row at the bottom of the screen. **************************************************************** **************************************************************** WHATSNEW in 15OCT98 AIPS AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET98B.PS **************************************************************** VLB matters: 1. FITLD improvements: a. Calibration transfer from the correlator into AIPS data sets has been implemented. It should no longer be necessary to copy log files into text files which are then read into AIPS. See ftp://ftp.aoc.nrao.edu/staff/cflatter/FITS-IDI.ps or http://www.aoc.nrao.edu/~cflatter/FITS-IDI.html for details. b. The computation of the reference frequency for lower sideband data was corrected. c. The renumbering of sources was improved to avoid excessive source numbers and confusion over CALCODEs. 2. Fringe-fitting in KRING was improved a. to attempt forward and backward extrapolation of solutions in order to avoid excess computation. b. The SNR is now computed in a new and self-consistent way See http://www.cv.nrao.edu/aips/TEXT/PUBL/AIPSMEM101.PS for details. 3. Delay calibration was not previously applied if it was zero for the first IF/channel. Now all values are checked and used. General uv data and calibration: 4. SPLAT - is a new task to apply calibration and average the output over time and/or spectral channels. 5. SPLIT - was revised to average spectral channels after calibration, to handle multiple subarrays as advertised, to count samples better, and to omit the REMOVED random parameter. 6. The interactive editing tasks (EDITR, EDITA, SNEDT and the editing in SCMAP) were revised to allow editing in crowded displays and to provide a number of other improvements in the speed with which data may be flagged. 7. Numerous errors in BPASS were corrected. Channel-dependent data flagging led to improper weighting of channels, bad interpolation across missing channels and other problems. The application of BPASS solutions from autocorrelation data to cross-correlation data and vice versa was fundamentally in error. A missing antenna in an AN table caused addressing failures. 8. FLGIT - is a new task to remove RFI-affected samples from low-frequency, multi-channel data sets. 9. UVCOP can now apply up to 50,000 flags at a single time (ten times more than the rest of AIPS). 10. Times in SN and CL tables no longer need to be the same for all antennas. Imaging and modeling: 11. CONFI - is a new task to optimize array configuration designs. 12. The NVSS web site may now be used to prepare field parameters for input to IMAGR. See http://www.cv.nrao.edu/~bcotton/NVSSAIPS.html. 13. FLATN can now apply geometric corrections while flattening a 3D multi-field set of images. 14. Radial bandwidth smearing corrections are available in SAD, IMFIT, and JMFIT. 15. OMFIT has steadily acquired the ability to model the universe. Data display: 16. XAS is now able to do 24-bit TrueColor displays on monitors which support such things. This allows true 3-color images and full hue-intensity displays. 17. Split screen and roam were added to XAS as well. They work best in the 24-bit mode but are usable in 8-bit. 18. You may now have as many TV displays, message terminals, etc as you want. Only one may be connected to the Internet but one can have 1 or more local Unix socket displays. This means that XAS runs on the same computer as, for example, IMAGR and AIPS. The images may appear on any computer or X-terminal display selected by the $DISPLAY variable. 19. Printing to the terminal may be set to detect the size of the current terminal (e.g. xterm) window and to pause when that size is filled. Previously, the official window size was stored in a file and the actual size was ignored. 20. POPS now has a much larger area for storing procedure, new variables, etc. **************************************************************** **************************************************************** WHATSNEW in 15APR98 AIPS AIPSLetter: http://www.cv.nrao.edu/aips/TEXT/PUBL/LET98A.PS **************************************************************** The "CVX" ("Charlottesville Experimental") version of AIPS has been renamed the 15APR98 version. It uses somewhat revised data formats from the older versions. It is able to read and convert headers and BP tables written by the older versions, but the older versions CANNOT handle data written by 15APR98. The adverbs have changed enough that SAVE/GET files are also not interchangeable. Through a clever trick, 15APR98 is able to read older SAVE/GET files, but the older versions are unable to read 15APR98's files. Also, NEW/OLD tasks may not be started from 15APR98 aips and 15APR98 tasks may not be started from NEW or OLD aips. (The 15APR98 one is larger and forced changes in the task-communication file.) The TV displays are no longer compatible; the one in 15APR98 has improved communication methods and the image catalog and TV description files have been eliminated. ***** IN SUMMARY, ONCE YOU START USING 15APR98 YOU *********** ***** MUST FORGET ABOUT EARLIER RELEASES. *********** Eric Greisen **************************************************************** 1. INDXR rewritten, but use INDXH for multi-FQ data sets. 9548 2. UVFIX handles orbiting VLBI. 3. New tasks M3TAR to read MkIII data in Unix tar archives and TFILE which sorts and edits AFILES for M3TAR. 4. POLCO now has a smooth function for all S/N ratios. 5. PBCOR has a DOINVERS option. 6. IMERG can optionally use a smooth weighting function across UVRANGE rather than a step function. 7. COMB now takes 2 noise images as well as two data images and has numerous other changes. 9607 8. IMMOD and UVMOD now support uniform sphere and exponential disk models. 9. FILLM offers a proper van Vleck correction for high S/N continuum data. It now tests for data out of order and is more careful in deciding when to make new FQ numbers (doing it less one hopes). 10. Up to 16384 channels * IFs * polarizations may now be supported in a single visibility record. 11. BPASS no longer (incorrectly) supports the BCHAN/ECHAN and STOKES options. It now uses dynamic memory to hold any size problem. Unweighted modes DOBAND 4,5 are now supported for BP application and BPSMO can do weighted or unweighted smoothing. A serious bug was corrected which affected re-referencing phases when the solutions for channel 1 had failed. 12. New verbs COSTAR, COWINDOW, COTVLOD to plot symbols, select windows, load TVs centered on a specific coordinate. 13. COHER determines coherence time for zero and non-zero fringe rates. 14. Bugs in gridding data and in the running average in TVFLG and SPFLG were corrected. The first caused data to appear at slightly wrong times and the latter could mix data from two sources causing the data to appear to be bad. 15. UVCOP can now apply a flag table while copying the data. 16. ASCAL (and friends ASCOR, GNSMO, GAPLT, VSCAL, GNMRG, PRTGA, GNPLT) encountered a silver stake at midnight and will now only be found at full moon. 17. DBCON now does a correct, frequency-dependent phase shift for all single-source files (DOPOS > 0) and can handle one or both inputs in compressed form with full generality. **************************************************************** CVX CHANGES FOR THE 15APR98 VERSION ******** A, The CookBook ******** The AIPS CookBook has had to be modified for 15APR98. You can access the individual chapters (as PostScript files) through WWW starting at the aips home page. The introductory chapters (1 and 2) had minor revisions made to update the code sizes and various 15APR98 related matters. The basic utilities chapter (3) was revised to correct the WWW address for 15APR98, to delete version references for Chapter 13, and to update the description of HELP. The calibration chapter (4) was revised to describe the new and significant task EDITA, to update FILLM's use of system temperatures, to describe the closure reporting in CALIB, and to describe additions and changes to bandpass calibration techniques. The imaging chapter (5) was updated to describe added BOXFILE capabilities and the new "3D" and "overlapped" imaging and to describe EDITR rather than the old IBLED baseline-editor task. The VLBI chapter (9) was modified to mention SCMAP, EDITR, and SNEDT and to include an additional picture. The chapter on single-dish data (10) has been modified to describe beam-switched continuum analysis and numerous other improvements to on-the-fly imaging in 15APR98. The list of AIPS symbols by type (13 = the ABOUT files) was brought up to date. The Index, Table of Contents, and html files have been modified to match these changes plus changes to the VLBI chapter made by others. A new, still developing, version of the VLBI chapter has appeared. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** B. VLA and VLBA ******** 1. FILLM: Changed to produce weights = 1/sigma**2 using calibrated Tant values produced by the VLA on-line system since about May 1, 1996. The new-style weights can be forced with a new bit option in CPARM(2) but the calibration of the Tant may still not be good enough for this usage. Changed CPARM(8) to NCOUNT and made CPARM(8) the interval to use for TY tables (default = input data interval). Corrected bug in handling table intervals. A van Vleck correction may be made for high S/N data, but only for continuum data at present. It now tests for data out of time order and makes new FQ numbers less often due to more careful tests on the parameters. print: Changed PRTUV, PRTSD, UVPRT, PRTSD, UVDIF, and UVFND to examine and, if needed, scale the weights to get a meaningful display. 2. Up to 50 extension file types are now supported. Translation of headers from the previous limit of 20 is automatic. ***** NB older versions may have problems with headers ******** ***** created by 15APR98 because of this. ******** 3. File sizes greater than 2 Gbytes are now allowed. They can be created only on DEC Alpha, SGI, and Solaris 2.6 computers at present, but all limitations in non-system-dependent routines have been removed. The disk I/O routines had numerous extra "lseek" calls inhibited. 4. INDXR can now merge atmospheric delay and clock offset data from MC tables when creating a CL table. 5. UVFIX now handles orbiting VLBI as do numerous other tasks. 6. The new tasks M3TAR to read MkIII data in Unix tar archives and TFILE to sort and edit AFILEs for M3TAR were submitted from MPI Bonn. 7. The largest visibility record (the product of number of spectral channels, number of IFs, and number of polarizations) was doubled to 16384. All AIPS tasks should be able to handle this (if slowly). 8. COHER: determines coherence times in data even for non-zero fringe rates. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** C. Interferometric imaging ******** 1. "3D imaging" - Changed IMAGR to offer the option of re-projecting the baselines onto the center of each field. This makes each field tangent to the celestial sphere. Previously - and with DO3DIM false - each field is parallel to the initial tangent point. The re-projection allows distant fields to remain "in focus" over a much wider area. Almost all of 15APR98 AIPS now understands these images, handling Clean component models made with or without the re-projection. Thus CALIB, UVSUB, FRING, BPASS, PCAL, etc. can handle such models as can VPLOT, CLPLT, and IBLED. The cost of this option has yet to be measured properly but appears tolerable. The option is essential for P BAND imaging with even modest resolutions. 2. The maximum number of fields for imaging was changed from 16 to 64. This changed the dimension of adverbs FLDSIZE, RASHIFT, DECSHIFT, BCOMP, and NCOMP. It also forced changes in system I/O structures and in the Task-Data intercommunication file (IMAGR, the task used to compute these images, now requires 782 words of adverb values!). IMAGR will read in field parameters from the adverbs and also from the optional BOXFILE. Do a HELP BOXFILE to see how to use that file to save problems typing in large numbers of adverbs in complex problems. (The BOXFILE option for field parameters was not added to MX or WFCLN - use IMAGR, they are obsolete.) The maximum number of Clean boxes was reduced from 500 to 256 per field for IMAGR and WFCLN. 3. IMAGR was given the ability to restore Clean components to all fields in which they occur, not just the field in which they were found. IMAGR was also given a new mode of sequencing the imaging and Cleaning that should allow the same direction to be Cleaned from two or more fields without the previous instabilities and slow convergence. 4. FLATN is a new task to create a single (large) output image by re-projecting all fields onto a single coordinate grid. 5. SCMAP is the task used to make images using iterative deconvolution and self-calibration steps. It was revised to allow the full capability of EDITR to be selected from the self-calibration TV menu. SCMAP now compares with DIFMAP for VLB and even VLA imaging. It has acquired interactive options to abort the task, to switch to amplitude and phase solutions from phase-only solutions, and to reset a wide range of parameters. When doing amplitude and phase solutions, it can apply a time smoothing to the solution amplitudes before applying them to the data. This smoothing is also used to interpolate over failed amplitude and phase solutions in the hope that they won't fail in the next iteration. 6. UVSUB now has an option to write out the model evaluated at the input sample points instead of the difference or ration of the observations and model. 7. IMAGR: The operation which caused it to take a long time to end after writing the restored image was replaced by a nearly zero cost operation while the data are first read. The work file may be re-used, although the data in it are never re-used. An ABORT-TASK option was added to the interactive TV menu. 8. VPLOT: The 15APR98 versions of VPLOT, CLPLT, and IBLED compute models correctly and support the 3D imaging option. The older versions have an error in the model computation and CLPLT does not read the data correctly. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** D. Interferometric Calibration ******** 1. The bandpass tables have been changed to include weights which depend on IF and polarization. BPASS will compute them and the calibration application routines (and POSSM) will use them. Older format bandpass tables will continue to function, with the missing weights taken from the "interval" column. The new application routines are able to do nearest neighbor and two-point interpolation on the bandpass table with weights (DOBAND 2 and 3, resp.) and without weights (DOBAND 4 and 5, resp.) as well as using the overall average bandpasses. Dynamic memory is used which means that all tasks will use as much or as little memory as needed. CVEL also works with all values of DOBAND to shift observations to a common velocity. BPASS: In determining bandpass calibration functions from the data, the algorithm was improved to correct data weights to take into account low fluxes in the continuum division. New adverbs and print controls were added to summarize closure failures. Adverbs BCHAN, ECHAN, and STOKES, which caused errors, were dropped from the task. Bugs affecting re-referencing phases were corrected. Dynamic memory is now used throughout to allow the program to run in the space needed be it large or small. BPERR: A new task to read closure error reports from text files generated by BPASS and PRTMSG. Averaged and summed reports and plots are generated. 2. BPSMO: A new task which makes a regularly gridded (in time) BP table via several different interpolation schemes. It has an option to insure amplitude normalization over a range of channels and does all interpolation and normalization in either full vector or amplitude-scalar modes. It can do weighted or un-weighted smoothing and offers options affecting the output weights. BPSMO may also be used just to fill in blanked (i.e. failed or flagged) solutions leaving the others alone. 3. BPLOT: A new task to plot bandpasses as profiles in two dimensions. Multiple times for one antenna or multiple antennas for one time appear in each plot and multiple plots can be produced. Multiple IFs and/or polarizations may appear along the horizontal axis. 4. UJOIN: A new task to "join" multiple, overlapped IFs either averaging the overlapped channels or differencing them. With the new, better bandpasses, this may become a standard operation to be done before UVLSF or UVLIN. 5. CALIB: Added adverbs MINAMPER and MINPHSER and changed the meanings of APARM(6) (print control), CPARM(3), and CPARM(4) to allow more complete examination of closure errors without too much printing. 6. UVMLN: A new task to apply preliminary calibrations (continuum and, especially, bandpass) to a multi-source file, then fit a baseline to each record (uv spectrum), and generate flags whenever residuals in the baseline-fitting regions exceed specified limits. This will let you remove bad samples, and re-determine the calibration with cleaner data. 7. ASCAL: This old task, which ignored IFs > 1, has been deleted. Its supporting cast (VSCAL, ASCOR, GNSMO, GNMRG, GAPLT, GNPLT, PRTGA) has also been removed. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** E. Data editing and handling ******** 1. EDITA is a new task that allows you to prepare uv-data flag commands interactively from displays of TY (system temperature), SN (gain solution), and CL (calibration) tables. It is similar to SNEDT (without the smoothing options), but prepares Flag Commands which can then be copied into uv-data FG (flag) tables. It applies a pre-existing FG table to the TY, SN, or CL data as they are read so that you do not need to flag those data more than once. EDITA talks in user-friendly units for delay and rate although it uses sec and sec/sec internally to match the units of the SN/CL files. 2. EDITR is a new task that allows you to prepare uv-data flag commands interactively from displays of the uv data and, optionally, a related uv data set (e.g. a residual data set from IMAGR, SCMAP, or UVSUB). It is a graphics-based editor like EDITA, SNEDT, and (distantly) IBLED. It allows you to look at up to 10 baselines to the selected antenna at the same time and to view and edit upon amplitude and phase of the data and of the difference between the data and a running vector mean of the data. 3. TV editors: TVFLG, SPFLG, EDITR, EDITA all allow you to enter a REASON string for subsequent flag commands. Problems with gridding data in IBLED, TVFLG and SPFLG have been addressed. 4. UVCOP: can now apply a flag table, deleting data, while doing the copy. 5. DIFUV: A new task to write out the difference of two matching uv data sets. Its main uses will probably be (1) to make a difference beam-switched single-dish data file for use in examining and perhaps editing the data before imaging and (2) to make a uv file of the data model by subtracting the residual from the input. 6. FIXWT: This new task was not counting flagged data correctly and deleted way too much on output. Fixed reports and also its handling of autocorrelation data. Corrected bug that discarded the last XINC samples, added user control over the "scan" break interval, and made it smarter in handling "short" scans. 7. DTSUM: Changed task to handle single-dish data, single-source data, and missing tables usefully. 8. SPECR: Changed task to work. Previously it did not do the right things at least when increasing the number of channels except for the very first spectrum. Also made it handle autocorrelation data correctly. 9. FXTIM: New task to fix times in uv data sets if a wrong reference date was selected (leading to negative times). 10. DBCON: Changed task to apply all corrections to compressed as well as uncompressed data. The two data sets do not have to have the same compression state. Corrected the DOPOS phase correction to use frequency at all times and to do it correctly. 11. Corrected calibration to use the baseline-dependent cal array only when requested rather than filling it laboriously with 1's and 0's and then doing complex multiplies. Worse yet, it caused large problems to die if the array was too small (which it is by a factor of 30 or so in the worst case) even when it really was not used. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** F. Single-dish spectral-line imaging ******** 1. **** BUGS OF NOTE **** : The circular convolving functions of SDGRD were found to have an addressing error. The effect was to move the object one-half pixel toward decreasing X and toward increasing Y. So far as I know, this bug is still in the older AIPS versions. Corrected December 19, 1996. Another bug causing bad values of circular convolving functions to be used was found and fixed 6 January 1998. This should either have used 0 (nearly the right value anyway) or really bad values producing obvious effects. **************************** 2. OTFUV: OTFUV translates NRAO 12m "on-the-fly" spectral-line data into AIPS format. An option to interpolate the OFF and Gain measurements in time before applying them to the ON data was added. In addition, the ability to read up to 8 "IFs" at a time (from BIF to EIF but excluding those that do not match BIF's frequency center and increment) was added. This option avoids the later need for a sort. Lower-case file names are now allowed. 3. OTFIN: A new task to print an index of the contents of a 12m "on-the-fly" data file. 4. SDLSF: A new task to average all spectra observed at the same time, fit a linear baseline to the average, and then subtract that baseline from each spectrum. This is an attempt to remove the "weather" before imaging, but its main effect may be to avoid the TRANS-IMLIN-TRANS process used after imaging to remove the spectral baseline. For multi-feed instruments dominated by instrumental effects, the option to remove a baseline from each spectrum individually has been added. 5. SDVEL: New task to shift single-dish spectra to the correct velocity for the actual time and pointing position. The velocity error in a 2x2 degree field can be as much as 1.2 km/sec which is significant at mm wavelengths. VTEST: New task to help determine how big this effect can be. 6. SDIMG: New name for the previous SDGRD task which is able to make very large images from single-dish data. 7. SDGRD: This task converts single-dish data into images, potentially having multiple spectral channels. It was completely rewritten to be an OOP task. It is now limited to images small enough to fit one plane into the pseudo AP, but it does not require the, potentially, very large scratch file still used by SDIMG. The cpu time may be longer than SDIMG since the coordinate projection has to be repeated for each set of spectral channels, but the real time is usually less. 8. WTSUM: This task is used to do weighted averages or sums of images using images of the weights. It has been given the option to average a large number of input images in a single execution, looping over the image "sequence" number. 9. many: Numerous tasks were fixed to force the "imaginary part" of single-dish visibilities to 0. This part of the data is used to store applied offsets and, hence, is not automatically 0. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** G. Single-dish continuum imaging ******** 1. A package of tasks to handle beam-switched on-the-fly continuum imaging from the NRAO 12m is in the process of development: OTFBS: A new task to read beam-switched continuum data and make two AIPS uv data sets, one for "plus" throws and one for "minus". 2. BSGRD: A new task to make a beam-switched image in standard coordinates by imaging the plus and minus throws, rotating the two images, correcting them by the standard convolutional algorithm, and then regridding into standard coordinates. It combines SDGRD, OGEOM, BSCOR, and BSGEO. 3. BSCOR: A new task to combine images made with plus and minus beam switching using the "standard" convolutional algorithm. The results have not been exciting and suggest that a new algorithm may be needed. BSCOR is now coded as a class method in the AIPS OOP system. 4. BSGEO: A new task to regrid the output of BSCOR into a standard right ascension by declination image. It is coded in OOP. 5. BSAVG: A new task to average multiple BS images using a weighting in the Fourier transform space. 6. BSTST: New task to test and plot one-dimensional beam-switched restoration (really frequency switched in 1-D). Options to include various instrumental errors are available. 7. BSFIX: A new task to compute and correct the RA and declination offsets in beam-switched data. 8. SDMOD: This task subtracts a model from single-dish data or replaces the data with a model. Models are up to 4 Gaussians or, now, an image. Beam-switched data may be modeled including instrumental errors such as throw length. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** H. General imaging ******** 1. OGEOM: This new task rotates and re-scales the geometry of an image, writing a new image. It handles blanked pixels properly, allowing small blanked regions to be filled in. Older tasks like LGEOM increase the blanked area with each application. OHGEO, which does a more complicated re-gridding, was also enhanced to give the user more controls. 2. SERCH: This new task uses algorithms developed by Juan Uson to convolve the spectra in a data cube with Gaussians of various widths and then report those pixels/channels having signal/noise exceeding a user selected cutoff. This is a good way to find weak signals in large cubes. The pixels found may be written out in a hyper-cube of S/N. 3. ISPEC: Changed to better output formats and to offer the option of plotting flux rather than average brightness. 4. BLSUM: Changed task print level controls, corrected handling of units, labels, and even which image's header is used to control those matters. 5. XBASL: Changed handling of blanks and internal logic to make it friendlier for spectral-line (esp single-dish) users. Some of the changes were made in XPLOT and XGAUS as well. 6. POLCO: Changed the task to do a low S/N solution for the correction as well as the previous, higher S/N correction. This allows noise in the corrected image to be estimated properly. 7. COMB: Changed to allow noise images to be input rather than simple constants. A noise image may be written at the same time as the usual product image. PANG has a new clip level on the total polarization; SPIX and OPTD also have new clip level parameters. POLC now uses Jim Condon's method covering the full range of S/N. Most prohibitions were dropped and several defaults changed. 8. IMERG: Changed to offer a smooth weighting of the two FFTs within UVRANGE as well as the previous step function. 9. IMMOD: Added uniform sphere and infinite exponential disk models UVMOD: and changed the meaning of some parameters. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** I. Display and general matters ******** 1. XAS: The TV now has a number of improvements. They include: (a) a new icon (b) 4 grey-scale memories rather than 2 to allow for better movies (c) initialization, character generation, vector drawing, and area fill are now done by XAS itself to reduce I/O (d) XAS maintains the device characteristics common values in a device-independent manner. They are reset when a new XAS begins and ID files are no longer used. (e) XAS maintains the image catalog in a device-independent manner which means that it is reset when a new XAS begins and it may be used correctly by any computer anywhere. IC files are no longer needed. (f) Access to XAS is controlled by a new server program TVSERV. Tasks wanting to use XAS on computer Host ask the TVSERV on Host for permission to use it. Previously, remote requests would hang until the TV became available; now they hang until TVSERV is available (which will be milliseconds at most). Access over networks is improved by corrections that remove the assumption that $AIPS_ROOT is the same at all sites. It is now entirely feasible to run at a very remote site while having XAS et al. on your desk. 2. XAS and other servers: All servers will now work with Unix as well as Internet sockets. The servers have all been given interrupt handling and close-down procedures. Unix sockets should be faster - as soon as we get them fully implemented - when the compute and display servers are the same. they should allow us to support multiple display servers on a single host (each with its own X terminal or other display output device). 3. SNPLT: Adverb FACTOR was added to allow control of the size of the plot symbols. They were too large under some circumstances. A bug preventing the plotting of error bars was fixed. 4. PRTAB: Adverbs NCOUNT, BDROP, EDROP, and BOX were added to allow control of which elements in arrays are printed (1-NCOUNT and BDROP-EDROP) and of which columns are printed in what order (all or as listed in BOX). Handling of flagged rows was corrected. 5. TVMOVIE: Button D may now terminate the movie loading in case you have gotten the adverbs wrong (which I always seem to do). 6. TVCPS: Changed task to use the zoom and scroll parameters so that it is much more WYSIWYG. 7. HELP: Changed this verb (and EXPLAIN) to use the TASK adverb when there is no immediate argument. 8. PRINTER: New verb developed by Pat Murphy to allow interactive changes to the output print device. 9. PRTSD and UVPRT: Changed these two tasks to use BCOUNT as an offset into the file rather than reading the first BCOUNT records before printing. This makes the effect of BCOUNT independent of the other adverbs and hence predictable and very much faster. 10. KNTR: Added option to have the step wedge over the full range of image intensity rather than just PIXRANGE. 11. COSTAR: New verb to plot a symbol at a coordinate on the TV. COWINDOW: New verb to set BLC and TRC to be centered on a coordinate. COTVLOD: New procedure to load the TV with a window centered on a coordinate. *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* ******** J. System matters ******** 1. Added a host speed parameter so that various delays may be made shorter on faster computers. Examples are how often AIPS checks to see if a task is running when DOWAIT is true. 2. Added a translation of $HOST to the internals of AIPS. This name is then used on printouts, accounting, etc. rather than the SYSNAM which is "UNREGISTERED!!!!!" on all machines that are not registered. This fix keeps two hosts from destroying each others scratch files on shared data areas. 3. Esthetic and real problems with the year 2000 have been addressed. 15APR98 already reads the proposed new FITS date format and is poised to write it when allowed to do so. Both the old and new date formats are handled internally and transparently. 4. 15APR98 now supports a Solaris-like "operating system" called SUL to allow Ultra-specific and non-specific Solaris versions to co-exist. It also supports HP2, the most modern hardware on HP computers. 5. The number of tape drives is determined from a local environment variable set in the AIPS startup rather than depending on the contents of the hand-maintained SP file. ----------------------------------------------------------------