SCHED  Input and Output Files

SCHED  takes input from several types of files in addition to any interactive input. All of these files can be separate, as long as SCHED  can find them, or most of them can be imbedded in the main input file. The former is more convenient. But, when the input file is to be sent somewhere else to be run again, it may be safer to imbed the catalog information in the main file. All input to SCHED  is in the keyin free format. This is the same format as is used by all Caltech VLBI package programs. The input file types are:

Main Schedule Input File:

This is the file that contains the details of the particular project. It can have the most of the other files imbedded in it. This file must be created by the user. This file should be given a name like bv016.key for project BV016.

Source Catalog:

This file contains the information about the sources, especially names, positions, and, for line sources, velocities. There are standard source catalogs, although the user may need to add non-standard sources. Source catalog entries can be included in the Main Schedule Input File.

Station Catalog:

This file contains information about the antennas including names, positions, slew limits, horizons etc. There is a standard station catalog that should suffice for nearly all users. If not, entries can be included in the Main Schedule Input File. Station positions may stored sparately in the Location Catalog

Location Catalog:

This file contains station locations. The standard version reflects the locations and velocities used on the VLBA correlator. It is documented along with the [Station Catalog because they are tightly coupled. The Locations Catalog is optional since it is not needed if the station locations are specified in the Station Catalog. It exists separately for ease of maintenance.

Setup Files:

These files contain the details required to configure the hardware at the stations. Different projects using the same hardware configuration can use the same setup files. There are many standard setup files. Setup file names conventionally end in .set.

Frequency Catalog:

This file contains information about valid frequency setups at the stations. The RF ranges that can be covered and the local oscillator and polarization of each IF are given. SCHED  can use this information to provide good defaults for many parameters in the setup files. The standard file should be used. Any non-standard information can be in the setup files. This file cannot be imbedded in the main input file.

Tape Initialization File:

This file tells SCHED  the properties of the tape systems at the stations and where to start on each tape. For most experiments, the default tape initialization parameters will be adequate and this file need not be provided. The main exceptions are observations using thick tapes at some sites.

Reference Pointing Control File:

SCHED  can insert scans for reference pointing at high frequencies on the VLBA and VLA. This file contains information needed to control that function. It will only be of interest for observations at 43 GHz on the VLA and at 86 GHz on the VLBA.

Spectral Line Rest Frequencies:

SCHED  can adjust the observing frequency to remove the doppler shifts due to the motions of the Earth around the Sun and to the Sun with respect to a desired reference frame. To do this, SCHED  needs to know the rest frequency of the line being observed. This is given in a lineinit section imbedded either in the main file or in the reference pointing control file.

SCHED  processes the input files and creates several output files. Most follow a naming convention where that starts with the project code (BV016 will be used in the examples here) followed by a file type indicator, then a period, then a two letter station code (pt for Pie Town in the examples below). The experiment code is read by SCHED  in the EXPCODE parameter in the main schedule input. The station code comes from the station catalog and a list if given in Appendix A.4. The output files are:

Summary File:

This file gives a rather extensive summary of the setups and observations. This is the most useful output file for the user as it shows how SCHED  has interpreted the input commands. The file will be called, for example, bv016.sum. The items displayed for each scan can be controlled with the parameter SUMITEM.

sched.runlog:

This file reflects most of what you see on the screen when SCHED  is running, plus may contain additional messages that help debug problems should they occur.

Operator Schedule Files:

These files, of which there is one per antenna, give much information the schedule than can be included in the summary file and are useful when that level of detail is needed. They were originally meant for the use of operators of manually controlled antennas, but now most antennas are computer controlled and these files are more useful for the scheduler. The files are named, for example, bv016sch.pt.

VLBA type Antenna Control Files:

These files provide the on-line control systems of the type found at VLBA antennas with the information they need to control the observations. There is one file per antenna that uses a VLBA control computer for either full control of the station or for control of just the data aquisition system (tape drives, baseband converters etc.). The files are named, for example, bv016crd.pt.

Other Antenna Control Files:

These files are antenna control files in VLA observe deck format, Green Bank Card format, or SNAP (Mark III style, but SCHED  can make them for Mark II only). Some antennas, such as the VLA, require both crd. and obs. files. The files are named, for example, bv016obs.y for the VLA file.

Mark IV .skd Files in VEX format:

These are the files needed for stations under control of the Goddard ``Field System'', e.g. MkIV telescopes. Writing of such files is available in SCHED  (depending on switches in the Makefile). Reading of such files, in order to make control files for the VLBA, will be added later. They will be named, for example, bv016.skd. A single such file describes the observations for all antennas.

Flag file:

SCHED  writes a file with the .flag extension that can be helpful in data processing. It contains flag entries, in the format appropriate for the AIPS task UVFLG, that cover the times when the tape is moving, but the antenna is expected to be slewing. For the VLBA, the monitor flags would take care of such times, but for other types of stations, such information is not always available from the logs.

Plots:

Sched can make plots of u-v coverage and of various combinations of azimuth, elevation, paralactic angle, hour angle, UT, and GST against each other.

Optimized Schedule:

When one of SCHED's optimization modes is turned on, the program writes out a file, such as bv016.sch containing the basic scan inputs for a new main schedule file. If desired, the user can use this to construct, and perhaps modify, a new optimized main schedule input. This used to be the way all optimized schedules were constructed, but now that SCHED  fully processes an optimized schedule, it is rarely used or needed.

frequencies.list:

If the user specifies the parameter FREQLIST, SCHED  will read the frequency catalog and make a table of all known setups which can be used to make observations in the specified frequency range. Then SCHED  will quit without doing further processing. This is useful for planning and for information while making setup files.