README

Synopsis

The genvalobs program is a Python script that generates an XML file containing MoM specifications for a set of system validation observations for LOFAR. One can specify a target source (Cyg A, Vir A, 3C 196, Cas A), and a planned start date in UTC. The script will then generate an XML file with observations for all desired observing modes, using the specified target source and a given duration per observation and interval between observations.

The Genvalobs is based on the momxml library (included in this package), which can be used to write your own python scripts to generate XML files that can be imported to LOFAR’s MoM system.

Extensive documentation can be found in the doc/ directory. The generated HTML documentation is found in doc/_build/html/

Prerequisites

Python 2.6 or newer and pyephem (http://rhodesmill.org/pyephem/).

Installation

user@localhost:~/genvalobs/ $ sudo python2 setup.py install

Usage

usage: genvalobs [-h] [-o FILENAME] [-m CORRELATOR_MODE] [-d SECONDS]
[-g SECONDS] [-s STATION_SET] [-i STATION_NAMES] [-e STATION_NAMES] [–min-alt DEGREES] [–max-alt DEGREES] [-c CLOCK_MHZ] [-w SECONDS] [-t DATE_STRING] [-p MOM_NAME] [-k STATIONS_TO_KEEP] [-f FILE_NAME] [-v] [source]

The (optional) source name must be enclosed in single or double quotes if it contains spaces. The following sources are recommended:

  • “3C 48” / 48: LST 22:30–04:30
  • “3C 147” / 147: LST 02:30–08:30
  • “3C 196” / 196: LST 05:00–11:00
  • “3C 295” / 295: LST 11:00–17:00
  • “Cyg A” / cyg: LST 16:00–24:00

If no source is specified, the program chooses the source that is closest to the meridian at the central LST of the observing sequence. The program has separate calibrator lists for LBA and HBA observations and pulsars.

Although genvalobs has its own default sequence of observations, it is possible to read a custom set from an ASCII file with a fairly simple format. The specification consists of newline-separated observations where each observation is specified in a white-space separated line with format:

<ANTENNA_SET> <BAND> <SUBBANDS> <CLOCK> <BIT_MODE> <DATA_PRODUCTS>

  • ANTENNA_SET: one of LBA_INNER, LBA_OUTER, HBA_ZERO, HBA_ONE,

    HBA_DUAL, HBA_JOINED, HBA_ZERO_INNER, HBA_ONE_INNER, HBA_DUAL_INNER

  • FREQUENCY_BAND: LBA_LOW, LBA_HIGH, HBA_LOW, HBA_MID, HBA_HIGH

  • SUBBAND_LIST: comma-separated list of sub band ranges. Note: NO
    SPACES ALLOWED! Examples:
    • 12..499
    • 12..22,112..122,212..222
  • CLOCK_MHZ: either 200 or 160

  • BIT_MODE: either 4, 8, or 16

  • DATA_PRODUCTS: white-space separated list of products. Allowed:
    • XC (cross-correlation)
    • FE (fly’s eye)
    • CS (coherent stokes)
    • IS (incoherent stokes)
    • TR (TAB rings)

Empty lines are ignored, comments start with # end run until the end of the line.

Example file:

# Antennaset Band Subbands Clock Bits Products LBA_OUTER LBA_LOW 12..499 200 8 XC HBA_DUAL HBA_LOW 12..499 200 8 XC LBA_INNER LBA_HIGH 156..399 200 16 FE HBA_DUAL HBA_LOW 77..320 200 16 IS HBA_DUAL HBA_LOW 77..320 200 16 CS HBA_DUAL_INNER HBA_MID 66..309 160 16 XC IS

Note that the custom sequence is subject to the same filtering by options -m, -c, etc. as the default observing sequence. The last entry is using the 160 MHz clock. It will only be used in the observation sequence if the 160 MHz is selected using the -c / –clock option.

positional arguments:
source Force a source to be used for all observations,
bypassing genvalobs’ own heuristics.
optional arguments:
-h, --help show this help message and exit
-o FILENAME, --output FILENAME
 Name of the output file [lofar- validation-20140701-101048.xml].
-m CORRELATOR_MODE, --mode CORRELATOR_MODE
 Correlator modes to test. Choose one of XC (crosscorrelation), FE (Fly’s eye), IS (incoherent stokes), or CS (coherent stokes). One can specify more than one mode. If this argument is not spedified, all modes will be tested [XC,FE,CS,IS,TR].
-d SECONDS, --duration SECONDS
 Duration of individual observations in seconds [120].
-g SECONDS, --gap SECONDS
 Gap between observations in seconds [60].
-s STATION_SET, --stations STATION_SET
 One of superterp, core, remote, nl, eu, all, or none. EU stations that conflict with certain HBA1 core fields are excluded from the HBA_ONE, HBA_ONE_INNER, HBA_DUAL, and HBA_DUAL_INNER observations. They are taken along in all other observations [nl].
-i STATION_NAMES, --include STATION_NAMES
 Comma separated list of station names to include. No spaces allowed in the list. Example: -i cs013,de601,rs106
-e STATION_NAMES, --exclude STATION_NAMES
 Comma separated list of station names to exclude. No spaces allowed in the list. Example: -e cs013,de601,rs106
--min-alt DEGREES
 Minimum elevation for target sources [40.00].
--max-alt DEGREES
 Maximum elevation for target sources [70.00].
-c CLOCK_MHZ, --clocks CLOCK_MHZ
 Allowed clock frequencies. Choose 160 or 200. Option can be provided multiple times if more than one clock frequency is required.
-w SECONDS, --wait SECONDS
 Number of seconds until the first observation [540].
-t DATE_STRING, --start-date DATE_STRING
 Specify an exact date and time to start the first observation. Format: “yyyy/mm/dd hh:mm:ss.s”
-p MOM_NAME, --project MOM_NAME
 Name of the observations’ MoM project [‘2014LOFAROBS’].
-k STATIONS_TO_KEEP, --keep STATIONS_TO_KEEP
 In case of HBA_DUAL or HBA_ONE network conflicts, keep either “core”, “eu” stations, or “all” of them. [‘core’].
-f FILE_NAME, --from-file FILE_NAME
 Read a custom observing sequence from FILE_NAME.
-v, --version Print version number and exit.

Brightest 3C sources

Just for reference, sorted by brightness:

3CR RA B1950 DEC B1950 Vmag z S 178 MHz alpha b Comments
405 19 57 44.43 40 35 45.2 16.22 0.056
0.74 6 108SP,CYGA,SE G
274 12 28 17.55 12 40 01.5 8.70 0.004
0.76 75 M87,30SP,CL G
348 16 48 39.98 05 04 35.0 16.90 0.154 351.0 1.00 29 HER A,E,R174 G
353 17 17 53.29 -00 55 49.5 15.36 0.030 236.0 0.71 20 75ID,E G
123 04 33 55.21 29 34 12.6 21.7 0.218 189.0 0.70 -12 18,12ID,E,CL G
295 14 09 33.44 52 26 13.6 20.20 0.461 83.5 0.63 61 E,CL,SE(3727) G
196 08 09 59.42 48 22 07.2 17.60 0.871 68.2 0.79 33 Q
111 04 15 01. 37 54 20. 18.0 0.048 64.6 0.73 -9 SE,R=173 G
273 12 26 33.35 02 19 42.0 12.80 0.158 62.8 0.23 64 111SP Q
84 03 16 29.55 41 19 51.9 11.85 0.017 61.3 0.78 -13 N1275,PERA,CL G