Description of 'Albert's format'


 
  When data is found in this format, j2ms2 supports 'local' (i.e. relative to the experiment) and global (i.e. all experiments share these) databases. This applies to source and antenna databases only.
 
  For j2ms2 to work correctly in this case, it expects the following directory setup.
  1. Every experiment has its own directory, the experiment root-directory, <exp-root>
  2. Every subjob has its own directory, which is a subdirectory of the experiment root-directory, <subjob-root> (note: <subjob-root> is the RELATIVE name of the directory, so the <subjob-root> is the name of the subjob).
  3. Somewhere on the system, there must be a directory where the global databases live. This directory is passed to the program via an environment variable, J2MSDBPATH (short for: j2ms-database-path). Never mind if you forgot to set the environment variable because the program will complain on startup and won't continue!
Having done this, we take a look at the various files that j2ms2 expects.
Note: the contents are discussed here!
In the <exp-root>, j2ms2 checks the following ini-files:
  1. experiment.ini (fixed name, required): contains experiment settings
  2. frequency.ini (fixed name, required): contains frequency setups used in this experiment
  3. antenna.ini (fixed name, optional): contains antenna properties (if need/want to override global)
  4. source.ini (fixed name, optional): contains source properties (if need to overwrite entries in global database)
In the <subjob-root>, j2ms expects the following files:
  1. <subjob-root>.cor (fixed suffix, required): binary dump of correlated data
  2. <subjob-root>.dtd (fixed suffix, required): binary dump of Data Transfer Descriptor
  3. <subjob-root>.ini (fixed suffix, required): contains scan-specific settings
In the J2MSDBPATH-directory, the program looks for:
  1. antenna.ini (fixed name, optional): contains antenna properties
  2. source.ini (fixed name, optional): contains source properties

 
  Graphically:
 
...../<exp-root>/    
  /experiment.ini  
  /frequency.ini  
  [/source.ini]  
  [/antenna.ini]  
  /<subjob-root>/  
    /<subjob-root>.cor
    /<subjob-root>.dtd
    /<subjob-root>.ini

 
 
<J2MSDBPATH>/  
  [/antenna.ini]
  [/source.ini]

CONTENTS OF THE INIFILES

<exp-root>/experiment.ini
In this file, the following section is expected with the mentioned entries: <>
  • [Experiment]
    code=[string] <experiment code, eg fr002, gl34>
    msout=[string] <name of MS where scan-data is to be written to>
    domain=[time|frequency] <domain in which you want the data to be written>
    antennas=<stationcode>[,<stationcode>,...] <comma separated list of stationcodes of antennas used in this experiment>
    sources=<sourcecode>[,<sourcecode>,....] <comma separated list of sourcecodes of sources observed in this experiment>

      [vernierdelay = [on|off]] <Whether Vernier delay corrections were applied or not. If the value is not explicitly set, default is ON.>
    • 2) <exp-root>/frequency.ini The format of the frequency.ini is as follows. Per frequency setup one creates a section. The name of the section will be the identifier for that frequency-setup. Note: the name may not contain spaces. [<name of setup, eg. 4MHZ@32channels>] inttim=[string] <integration time, may contain units, like min, h, s, eg. 2min> polmap= <polarization map, maps zero/one in DTD to x,y,r or l> format of this entry is: <num>:<polcode>,<num>:<polcode> where: <num> = [0|1] <polcode> = [l|L|r|R|x|X|y|Y] Furthermore, the system reads CONSECUTIVE entries of the form subband<n>=... It starts reading at zero until a non-consecutive entry is found (includes no more entries, which is also non-consecutive) The format of a subband<n> entry is as follows: subband<n>= <double: startfreq>,<double: bandwidth>,<int: nrchannels>,<polarizations> where <polarizations> is: [xXyYrRlL:]* -> e.g. rr:lR:Lr or xr:rl:yy to indicate which polarizations were measured on this subband. NOTE: the startfreq/bandwidth values may contain units like mHz, GHz etc. 3) <subjob-root>/<subjob-root>.ini In this file one can specify the scan-specific settings. Also DTD properties may be set (if needed) The [DTD] section is optional, use it to set the following properties: [DTD] dtdoffset=[integer] <offset of DTD in binary file <subjob-root>.dtd> The [Scan] section is required. It should contain the following entries [Scan] source=[string] <the sourcecode of the source that was observed in this scan> frequencysetup=[string] <the name of the frequencysetup that was used whilst recording/correlating this scan> dateobs=[string] <date and time of start of scan. See MVTime documentation in aips++ to find out what formats are supported> [timesys=[string]] <optionally one can specify a timesystem for the dateobs. defaults to UTC> [bocfrate=[double]] <The number of BOCF/sec for this scan. Default = 0.0!!!> 4) The format of the local/global antenna.ini files is equal. An antenna.ini file should contain records of the following form: [<antenna code, eg. Jb>] name=[string] <full name of the telescope, like Arecibo> station=[string] <name of the station this telescope belongs to eg. VLA or WSRT> position= [<float>,<float>[,<float>]] <position of the telescope.> Interpretation is dependent on how many comma-separated arguments are found: - if two entries are found: attempt to form LAT/LON position, WGS84 as reference is assumed - if three entries are found: attempt to form XYZ position, ITRF assumed as reference (note: units with numbers are supported) diameter=[float] <diameter of the dish, units are supported, eg 3km = 3000m> 5) The format of the local/global source.ini. In a source.ini file records of the following structure are expected: [<sourcecode, eg. 3C86>] name=[string] <full name of the source, e.g. 'Centaurus X-1'> position=[<float>,<float>[,<epoch>]] <position of the source, see documentation on MVAngle in aips++ to see what formats are recognized. NOTE: <epoch> may be only 2000.0 or 1950.0 at this moment!>
    Marjolein Verkouter
    Last modified: Tue Nov 30 09:52:42 MET 1999