Contents
1 Introduction
1.1 The NRAO Project — A Summary
1.2 The ookook
1.3 Organization of the ookook
1.3.1 Contents
1.3.2 Minimum match
1.3.3 Fonts and what they signify
1.4 General structure of
2 Starting Up
2.1 Obtaining access to an computer
2.2 Using the workstation
2.2.1 Logging in to the workstation
2.2.2 Control characters on the workstation
2.2.3 Starting the AIPS program
2.2.4 Typing commands to the AIPS program
2.3 Managing windows
2.3.1 General window management
2.3.2 Managing the TV window called XAS
2.4 Additional recipes
3 Basic Utilities
3.1 Talking to
3.1.1 and utilities
3.1.2 Tasks
3.1.3 Verbs
3.1.4 Adverbs
3.2 Your message file
3.3 Your data catalog files
3.3.1 Speedy data file selection
3.3.2 Catalog entry status
3.3.3 Renaming data files
3.3.4 Header listings
3.4 Your history files
3.5 Saving and restoring inputs
3.6 Monitoring disk space
3.7 Moving and compressing files
3.8 Finding helpful information in
3.9 Magnetic tapes
3.9.1 Hardware tape mount
3.9.2 Software mounting local tapes
3.9.3 Software mounting REMOTE tapes
3.9.4 Using tapes in
3.10 external disk files
3.10.1 Disk text files
3.10.2 RUN files
3.10.3 FITS-disk files
3.10.4 Other binary data disk files
3.11 The array processor
3.12 Additional recipes
4 Calibrating Interferometer Data
4.1 Copying data into multi-source disk files
4.1.1 Reading EVLA archive files into
4.1.2 Reading data from FITS files with FITLD
4.2 Record keeping and data management
4.2.1 Calibrating data with multiple FQ entries
4.2.2 Recommended record keeping
4.3 Beginning the calibration
4.3.1 Baseline corrections
4.3.2 Correcting EVLA 3-bit data
4.3.3 Check your data with POSSM
4.3.4 Remove spectral ringing with SPLAT
4.3.5 General considerations in flagging
4.3.6 Correcting delay errors with FRING
4.3.7 Primary flux density calibrators
4.3.8 Calibrating the bandpass shape with BPASS
4.3.9 Calibrating the complex antenna gains with VLACALIB
4.3.9.1 Using calibrator models
4.3.9.2 Calibrating complex gains
4.3.9.3 Flux calibration without calibrator models
4.3.10 Bootstrapping secondary flux-density calibrators
4.3.11 Editing visibility data with EDITA
4.3.12 Applying solutions to the calibration table with CLCAL
4.3.13 Flagging RFI with RFLAG
4.3.14 Restart the calibration
4.3.15 Calibration with the SysPower table
4.3.16 Calibrating polarization
4.3.17 Additional calibrations for EVLA data
4.3.18 Making images from multi-source data with IMAGR
4.3.19 Back up your data with FITTP or FITAB
4.3.20 Creating single-source data files with SPLIT
4.4 Concluding remarks, early science
4.5 Additional recipes
5 Making Images from Interferometer Data
5.1 Preparing uv data for imaging
5.1.1 Indexing the data — PRTTP
5.1.2 Loading the data — FITLD and UVLOD
5.1.3 Sorting the data — UVSRT
5.1.4 Combining data sets for imaging — DBCON and VBGLU
5.2 Basic image making — IMAGR
5.2.1 Making a simple image
5.2.2 Imaging multiple fields and image coordinates
5.2.3 Data weighting
5.2.4 Cell and image size, shifting
5.2.5 Zero-spacing issues
5.3 Deconvolving images
5.3.1 Basic Cleaning with IMAGR
5.3.2 Multiple fields in IMAGR
5.3.3 Clean boxes and the TV in IMAGR
5.3.4 Experimental variations on Clean in IMAGR
5.3.4.1 Clean-component filtering
5.3.4.2 SDI modification of Clean in IMAGR
5.3.4.3 Multi-scale modification of Clean in IMAGR
5.3.4.4 Spectral-index corrections
5.3.5 Data correction options in IMAGR
5.3.5.1 Frequency-dependent primary-beam corrections
5.3.5.2 Frequency-dependent correction for average spectral index
5.3.5.3 Error in the assumed central frequency
5.3.5.4 Array mis-orientation effects
5.3.5.5 Non-coplanar effects
5.3.5.6 Units mismatch of residuals and Clean components
5.3.6 Manipulating Clean components
5.3.7 Image-plane deconvolution methods
5.4 Self-calibration
5.4.1 Self-calibration sequence and SCMAP or SCIMG
5.4.2 Self-calibration with CALIB
5.4.3 Considerations in setting CALIB inputs
5.4.4 Evaluating the quality of the imaging
5.4.5 Experimental extension of multi-field self-calibration
5.5 More editing of uv data
5.5.1 General remarks on, and tools for, editing
5.5.2 Baseline-based uv-data editing — EDITR
5.6 Imaging with OBIT, Complex imaging
5.7 Additional recipes
6 Displaying Your Data
6.1 Getting data into your catalog
6.1.1 IMLOD and FITLD from FITS-disk
6.1.2 Image coordinates
6.2 Printer displays of your data
6.2.1 Printing your visibility data
6.2.2 Printing your image data
6.2.3 Printing your table data
6.2.4 Printing miscellaneous information
6.3 Plotting your data
6.3.1 Plotting your visibility data
6.3.2 Plotting your image data
6.3.2.1 Contour and grey-scale plots
6.3.2.2 Row tracing plots
6.3.2.3 Miscellaneous image plots
6.3.3 Plotting your table data
6.3.4 Plotting miscellaneous information
6.4 Interactive TV displays of your data
6.4.1 Loading an image to the TV
6.4.2 Manipulating the TV display
6.4.3 Intensity and color transfer functions
6.4.4 Setting parameters with the TV
6.4.5 Reading image values from the TV
6.4.6 Labeling images on the TV
6.4.7 Comparing images on the TV
6.4.8 Slice files and the TV display
6.4.9 Other functions using the TV
6.4.10 Capturing the TV
6.5 Graphics displays of your data
6.5.1 Plotting data and setting values with the graphics display
6.5.2 Slice files and the graphics display
6.5.3 Data analysis with the graphics display
6.6 Additional recipes
6.7 Examples of color plotting
7 Analyzing Images
7.1 Combining two images (COMB)
7.1.1 Subtracting a continuum image from an image cube
7.1.2 Polarized intensity and position angle images
7.1.3 Other image combination options
7.1.4 Considerations in image combination
7.2 Combining more than two images (CMPLX, SUMIM, SPIXR, STACK)
7.3 Image statistics and flux integration
7.4 Blanking of images
7.5 Fitting of images
7.5.1 Centroid fits (IMCENTER) and parabolic fit to maximum (MAXFIT)
7.5.2 Two-dimensional Gaussian fitting (IMFIT, JMFIT)
7.5.3 Source recognition and fitting (SAD, TVSAD)
7.5.4 Gaussian fits to slices (SLFIT)
7.5.5 Spectral parameter fitting (TVSPC, XGAUS, ZEMAN, RMFIT, FARS)
7.6 Image analysis
7.6.1 Geometric conversions
7.6.2 Mathematical operations on a single image
7.6.3 Primary beam correction
7.6.4 Changing the resolution of an image
7.6.5 Filtering
7.7 Modeling in the image and uv planes
7.7.1 Analysis in the uv plane
7.8 Additional recipes
8 Spectral-Line Software
8.1 Data preparation and assessment
8.2 Editing and self-calibration
8.3 Continuum subtraction
8.4 Imaging
8.5 Display and manipulation of data cubes
8.5.1 Building and dismantling data cubes
8.5.2 Transposing the cube
8.5.3 Modifying the image header
8.5.4 Displaying the cube
8.6 Analysis
8.7 Additional recipes
9 Reducing VLBI Data in
9.1 VLBI data calibration recipe
9.2 Pipeline for the VLBA
9.3 Loading, fixing and inspecting data
9.3.1 Loading data from the VLBA correlator
9.3.1.1 Running FITLD
9.3.1.2 Calibration transfer
9.3.1.3 Repairing VLBA data after FITLD
9.3.1.4 Sorting and indexing VLBA correlator data
9.3.1.5 Subarraying VLBA correlator data
9.3.1.6 Indexing VLBA correlator data
9.3.1.7 Concatenating VLBA correlator data
9.3.1.8 Labeling VLBA correlator polarization data
9.3.1.9 Ionospheric corrections
9.3.1.10 Corrections to the Earth Orientation Parameters
9.3.1.11 Preparing the OB table for SVLBI data
9.3.1.12 Loading the time corrections file for SVLBI data
9.4 Tools for data examination
9.4.1 Textual displays
9.4.2 Spectral displays: POSSM
9.4.3 Time displays: VPLOT, CLPLT, and CAPLT
9.4.4 EDITR
9.4.5 SNPLT
9.4.6 COHER
9.4.7 FRPLT
9.5 Calibration strategy
9.5.1 Incremental calibration philosophy
9.5.1.1 Smoothing and applying corrections in SN and CL tables
9.5.1.2 Running CLCAL for phase referencing observations
9.5.2 Processing observing log and calibration information
9.5.2.1 Automatic formatting of VLBA and VLBA-like log files
9.5.2.2 Manual formatting of log files
9.5.2.3 Loading calibration log information
9.5.2.4 Generating VLA amplitude calibration with VLAMP
9.5.3 Data editing
9.5.4 Amplitude and instrumental delay calibration
9.5.4.1 Parallactic angle correction
9.5.4.2 Digital sampler bias corrections for VLBA correlator data
9.5.4.3 Instrumental phase corrections
9.5.4.4 “Manual” instrumental phase corrections
9.5.4.5 Bandpass calibration
9.5.4.6 Continuum amplitude calibration
9.5.5 Spectral-line Doppler correction
9.5.6 Spectral-line amplitude calibration
9.5.7 Phase calibration
9.5.7.1 Special considerations: SVLBI
9.5.7.2 Special considerations: spectral-line
9.5.7.3 Special considerations: polarization
9.5.7.4 Special considerations: phase-referencing
9.5.7.5 Correcting for atmospheric delays
9.5.7.6 Finding multi-band delays
9.5.7.7 Antenna-based fringe-fitting
9.5.7.8 Baseline-based fringe-fitting
9.5.7.9 SVLBI-specific techniques
9.5.7.10 Spectral-line fringe-fitting
9.5.7.11 Polarization-specific fringe-fitting
9.5.7.12 R-L delay calibration
9.5.7.13 Feed D-term calibration
9.5.8 Complex Bandpass
9.5.9 Baseline-based errors
9.6 After initial calibration
9.6.1 Applying calibration
9.6.2 Time averaging
9.6.3 Verifying calibration
9.7 Self-calibration, imaging, and model-fitting
9.7.1 CALIB
9.7.2 IMAGR, SCIMAG, and SCMAP
9.7.3 Non-conventional methods of imaging
9.8 Summary of VLBI calibration tables
9.9 Additional recipes
10 Single-Dish Data in
10.1 format for single-dish data
10.1.1 On-the-fly data from the 12m
10.1.1.1 Listing OTF input files
10.1.1.2 Reading spectral-line OTF files into
10.1.1.3 Reading continuum OTF files into
10.1.2 Other input data formats
10.2 Single-dish data in the “uv” domain
10.2.1 Using PRTSD, UVPLT, and POSSM to look at your data
10.2.2 Using UVFLG, SPFLG, and EDITR to edit your data
10.2.3 Using CSCOR and SDCAL to calibrate your data
10.2.4 Using SDLSF and SDVEL to correct your spectral-line data
10.2.5 Using SDMOD and BSMOD to model your data
10.3 Imaging single-dish data in
10.3.1 Normal single-dish imaging
10.3.2 Beam-switched continuum imaging
10.4 Analysis and display of single-dish data
10.4.1 Spectral baseline removal
10.4.2 Using WTSUM and BSAVG to combine images
10.4.3 Spectral moment analysis
10.4.4 Source modeling and fitting
10.4.5 Image displays
10.4.6 Backing up your data
10.5 Combining single-dish and interferometer data
11 Exiting from, and Solving Problems in,
11.1 Helping the programmers
11.2 Exiting from
11.2.1 Backups
11.2.2 Deleting your data
11.2.3 Exiting
11.3 Solving problems in using
11.3.1 “Terminal” problems
11.3.2 Disk data problems
11.3.3 Printer problems
11.3.4 Tape problems
12 for the More Sophisticated User
12.1 conventions
12.1.1 AIPS shortcuts
12.1.2 Data-file names and formats
12.2 Process control features of
12.2.1 RUN files
12.2.2 More about GO
12.2.3 Batch jobs
12.3 AIPS language
12.3.1 Using outside of procedures
12.3.2 Procedures
12.3.3 Writing your own programs with
12.3.3.1 Special facilities for use in procedures
12.4 Remote use of
12.4.1 Connections via X-Windows
12.4.2 Connections to a terminal
12.4.3 File transfer connections
12.5 Moving data to a new computer
12.6 Adding your own tasks to
12.6.1 Initial choices to make
12.6.2 Getting started
12.6.3 Initial check of code and procedures
12.6.4 Modifying an task
12.6.5 Modifying an template task.
12.6.6 Further remarks
13 Current Software
13.1 ADVERB
13.2 ANALYSIS
13.3 AP
13.4 ASTROMET
13.5 BATCH
13.6 CALIBRAT
13.7 CATALOG
13.8 COORDINA
13.9 EDITING
13.10 EXT-APPL
13.11 FITS
13.12 GENERAL
13.13 HARDCOPY
13.14 IMAGE-UT
13.15 IMAGE
13.16 IMAGING
13.17 INFORMAT
13.18 INTERACT
13.19 MODELING
13.20 OBSOLETE
13.21 ONED
13.22 OOP
13.23 OPTICAL
13.24 PARAFORM
13.25 PLOT
13.26 POLARIZA
13.27 POPS
13.28 PROCEDUR
13.29 PSEUDOVE
13.30 RUN
13.31 SINGLEDI
13.32 SPECTRAL
13.33 TABLE
13.34 TAPE
13.35 TASK
13.36 TV
13.37 TV-APPL
13.38 UTILITY
13.39 UV
13.40 VERB
13.41 VLA
13.42 VLBI
13.43 Additional recipes
A Easy Continuum UV-Data Calibration and Imaging
A.1 VLARUN
A.2 Basic calibration
A.3 Polarization calibration
A.4 Backup and imaging
A.5 Additional recipes
B A Step-by-Step Guide to Spectral-Line Data Analysis in
B.1 Editing and calibrating spectral-line data
B.1.1 Loading the data
B.1.2 Inspecting and editing the data
B.1.3 Calibrating the data
B.2 Making and Cleaning image cubes
B.3 Moment analysis and rotation curve of galaxies
B.4 Multi-frequency observations
B.4.1 General frequency information
B.4.2 Multi-frequency uv files
B.5 Additional recipes
C A Step-by-Step Recipe for VLBA Data Calibration in
C.1 Quick Guide
C.2 Table Philosophy
C.3 Data set assumed in this Appendix
C.4 VLBA Utilities
C.5 VLBA Pipeline
C.6 Data Loading and Inspection
C.7 Amplitude and Delay Calibration
C.8 Rate and Phase Calibration
C.9 Final Calibration Steps
C.10 Incorporating non-VLBA antennas
C.10.1 Loading Tsys and Gain Curves
C.10.2 Pointing Flags
C.11 Pre-EVLA VLA data
C.11.1 Single VLA Antenna
C.11.2 Phased VLA
C.12 Summary for non-VLBA antennas
C.13 Some Useful References
C.14 Additional recipes
D Hints for Reducing High-Frequency VLA Data in
D.1 Complications at higher frequencies
D.2 Additional recipes
O Special Considerations for Data from Older Telescopes in
O.1 The Historical VLA
O.1.1 Reading from VLA archive files using FILLM
O.1.2 Reading old spectral-line data
O.1.3 Applying nominal sensitivities to historic VLA data
O.1.4 Calibrating historic VLA data
O.1.5 Editing with LISTR and UVFLG
O.1.6 Editing with TVFLG
O.1.7 Spectral-line calibration
O.1.7.1 Spectral-line aspects of SETJY
O.1.7.2 Editing the spectral data
O.1.7.3 Calibrating the spectral data
O.1.8 Solar data calibration for the historic VLA
O.1.8.1 Reading solar data from the VLA archive
O.1.8.2 Using SNPLT and LISTR to assess the nominal sensitivities
O.1.8.3 Using SOLCL to apply the system-temperature correction
O.2 Old VLBI format data
O.2.1 Loading data from a MkIII/MkIV correlator
O.2.1.1 Running MK3IN
O.2.1.2 Sorting MkIII/IV data
O.2.1.3 Concatenating MkIII/IV data
O.2.1.4 Labeling correlator polarization data
O.2.1.5 Merging MkIII/IV data
O.2.1.6 Correcting MkIII/IV sideband phase offsets
O.2.1.7 Indexing MkIII/IV data
L Special Considerations for EVLA P-band Data Processing in
L.1 P-band calibration and editing in
L.2 P-band imaging in
L.3 Additional Recipes
F File Sizes
F.1 Visibility (uv) data sets
F.1.1 uv database sizes
F.1.2 Compressed format for uv data
F.2 Image files
F.3 Extension files
F.4 Storing data on tape
F.4.1 DAT and Exabyte tapes
F.5 Very large data sets
F.6 Additional recipes
V VLA Maintenance Tasks in
V.1 Real-time calibration tables: TLCAL
V.2 Correcting antenna positions: LOCIT
V.3 Improving antenna pointing: PEEK
V.4 Improving antenna surfaces: holography
V.5 Antenna polarization: PDPLT
Z System-Dependent Tips
Z.1 NRAO workstations — general information
Z.1.1 The “midnight” jobs
Z.1.2 Generating color hard copy
Z.1.2.1 Color printers
Z.1.2.2 Software to copy your screen
Z.1.3 Gripe, gripe, gripe, …
Z.1.4 Solving problems at the NRAO
Z.1.4.1 Booting the workstations
Z.1.4.2 Printout fails to appear
Z.1.4.3 Stopping excess printout
Z.1.4.4 CTRL Z problems
Z.1.4.5 “File system is full” message
Z.1.4.6 I can’t use my data disk!
Z.2 at the NRAO AOC in Socorro
Z.2.1 Reserving public-use workstations at the AOC
Z.2.2 Using Linux workstations at the AOC — introduction
Z.2.3 Starting
Z.2.3.1 Starting on another machine
Z.2.3.2 On-line FILLM
Z.3 at the NRAO in Charlottesville and Green Bank
Z.4 Additional recipes
G Glossary
I INDEX