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2.2.1 ALMA: Filling of Science Data Model (ASDM) data
The ALMA and JVLA projects have agreed upon a common archival science data model (ASDM) format, and have jointly developed the software to fill this data into CASA. In the ASDM format, the bulk of the data is contained in large binary data format (BDF) tables, with the meta-data and ancillary information in XML tables. This is structured as a directory, like the MS, and was designed to be similar to the MS to facilitate conversion.
The content of an ASDM can be listed with the task asdmsummary:
asdm = ’’ # Name of input ASDM directory
async = False # If true the taskname must be started using
# asdmsummary(...)
with an output that contains the list and positions of the antennas, followed by the parameters of each scan like observation time, source name, frequency and polarization setup:
========================================================================================
ASDM dataset :TDEM0008.sb3373760.eb3580330.55661.22790537037
========================================================================================
Exec Block : ExecBlock_0
Telescope : JVLA
Configuration name : B
Observer name : Dr. Juergen Ott
The exec block started on 2011-04-10T05:28:13.200000000 and ended on 2011-04-10T10:27:12.300000256
27 antennas have been used in this exec block.
Id Name Make Station Diameter X Y Z
Antenna_0 ea01 UNDEFINED W36 25 -1606841.96 -5042279.689 3551913.017
Antenna_1 ea02 UNDEFINED E20 25 -1599340.8 -5043150.965 3554065.219
Antenna_2 ea03 UNDEFINED E36 25 -1596127.728 -5045193.751 3552652.421
Antenna_3 ea04 UNDEFINED W28 25 -1604865.649 -5042190.04 3552962.365
Antenna_4 ea05 UNDEFINED W08 25 -1601614.091 -5042001.653 3554652.509
Antenna_5 ea06 UNDEFINED N24 25 -1600930.06 -5040316.397 3557330.397
Antenna_6 ea07 UNDEFINED E32 25 -1597053.116 -5044604.687 3553058.987
Antenna_7 ea08 UNDEFINED N28 25 -1600863.684 -5039885.318 3557965.319
Antenna_8 ea09 UNDEFINED E24 25 -1598663.09 -5043581.392 3553767.029
Antenna_9 ea10 UNDEFINED N32 25 -1600781.039 -5039347.456 3558761.542
Antenna_10 ea11 UNDEFINED E04 25 -1601068.79 -5042051.91 3554824.835
Antenna_11 ea12 UNDEFINED E08 25 -1600801.926 -5042219.366 3554706.448
Antenna_12 ea14 UNDEFINED W12 25 -1602044.903 -5042025.824 3554427.832
Antenna_13 ea15 UNDEFINED W24 25 -1604008.742 -5042135.828 3553403.707
Antenna_14 ea16 UNDEFINED N12 25 -1601110.052 -5041488.079 3555597.439
Antenna_15 ea17 UNDEFINED W32 25 -1605808.656 -5042230.082 3552459.202
Antenna_16 ea18 UNDEFINED N16 25 -1601061.961 -5041175.88 3556058.022
Antenna_17 ea19 UNDEFINED W04 25 -1601315.893 -5041985.32 3554808.305
Antenna_18 ea20 UNDEFINED N36 25 -1600690.606 -5038758.734 3559632.061
Antenna_19 ea21 UNDEFINED E12 25 -1600416.51 -5042462.45 3554536.041
Antenna_20 ea22 UNDEFINED N04 25 -1601173.979 -5041902.658 3554987.518
Antenna_21 ea23 UNDEFINED E16 25 -1599926.104 -5042772.967 3554319.789
Antenna_22 ea24 UNDEFINED W16 25 -1602592.854 -5042054.997 3554140.7
Antenna_23 ea25 UNDEFINED N20 25 -1601004.709 -5040802.809 3556610.133
Antenna_24 ea26 UNDEFINED W20 25 -1603249.685 -5042091.404 3553797.803
Antenna_25 ea27 UNDEFINED E28 25 -1597899.903 -5044068.676 3553432.445
Antenna_26 ea28 UNDEFINED N08 25 -1601147.94 -5041733.837 3555235.956
Number of scans in this exec Block : 234
scan #1 from 2011-04-10T05:28:13.200000000 to 2011-04-10T05:33:35.500000256
Intents : OBSERVE_TARGET
Sources : 1331+305=3C286
Subscan #1 from 2011-04-10T05:28:13.200000000 to 2011-04-10T05:33:35.500000256
Intent : UNSPECIFIED
Number of integrations : 322
Binary data in uid:///evla/bdf/1302413292901
Number of integrations : 322
Time sampling : INTEGRATION
Correlation Mode : CROSS_AND_AUTO
Spectral resolution type : FULL_RESOLUTION
Atmospheric phase correction : AP_UNCORRECTED
SpectralWindow_0 : numChan = 256, frame = TOPO, firstChan = 8484000000, chandWidth = 125000 x Polarization_0 : corr = RR,LL
scan #2 from 2011-04-10T05:33:35.500000256 to 2011-04-10T05:35:35.200000000
Intents : OBSERVE_TARGET
Sources : 1331+305=3C286
Subscan #1 from 2011-04-10T05:33:35.500000256 to 2011-04-10T05:35:35.200000000
Intent : UNSPECIFIED
Number of integrations : 119
Binary data in uid:///evla/bdf/1302413293280
Number of integrations : 119
Time sampling : INTEGRATION
Correlation Mode : CROSS_AND_AUTO
Spectral resolution type : FULL_RESOLUTION
Atmospheric phase correction : AP_UNCORRECTED
SpectralWindow_0 : numChan = 256, frame = TOPO, firstChan = 8484000000, chandWidth = 125000 x Polarization_0 : corr = RR,LL
scan #3 from 2011-04-10T05:35:35.200000000 to 2011-04-10T05:36:34.999999488
Intents : OBSERVE_TARGET
Sources : 1331+305=3C286
Subscan #1 from 2011-04-10T05:35:35.200000000 to 2011-04-10T05:36:34.999999488
...
The importasdm task will fill SDM1.2 and SDM1.3 format data into a CASA visibility data set (MS). ALMA data was recorded in SDM1.2 format from October 2009 until May 2011. Since May 2011, ALMA is using the SDM 1.3 format. In particular all science data from cycle 0 will be in SDM1.3. The JVLA also started using SDM1.2 in October 2009 and continues to use this format as of October 2011. The parameter useversion can be used to select between asdm2MW_v3 and asdm2MS, asdm2MW_v3 is the default.
The default inputs of importasdm are:
asdm = ’’ # Name of input asdm directory (on disk)
vis = ’’ # Root name of the ms to be created. Note the
# .ms is NOT added
singledish = False # Set true to output single-dish data format
corr_mode = ’all’ # specifies the correlation mode to be
# considered on input. A quoted string
# containing a sequence of ao, co, ac,or all
# separated by whitespaces is expected
srt = ’all’ # specifies the spectral resolution type to be
# considered on input. A quoted string
# containing a sequence of fr, ca, bw, or all
# separated by whitespaces is expected
time_sampling = ’all’ # specifies the time sampling (INTEGRATION
# and/or SUBINTEGRATION) to be considered on
# input. A quoted string containing a sequence
# of i, si, or all separated by whitespaces is
# expected
ocorr_mode = ’co’ # output data for correlation mode AUTO_ONLY
# (ao) or CROSS_ONLY (co) or CROSS_AND_AUTO
# (ca)
compression = False # Flag for turning on data compression
asis = ’’ # Creates verbatim copies of the ASDMtables in
# the ouput measurement set. Value given must
# be a string of table names separated by
# spaces; A * wildcard is allowed.
wvr_corrected_data = ’no’ # Specifies which values are considerd in the
# SDM binary data to fill the DATA column in
# the MAIN table of the MS. Expected values
# for this option are: no, for uncorrected
# data (default), yes, for the corrected data,
# and both, for for corrected and uncorrected
# data. Note if both is selected two
# measurement sets are created, one with
# uncorrected data and the other with
# corrected data.
scans = ’’ # processes only the specified scans. This
# value is a semicolon separated list of scan
# specifications. A scan specification
# consists in an exec bock index followed by
# the : character; followed by a comma
# separated list of scan indexes or scan index
# ranges. A scan index is relative to the exec
# block it belongs to. Scan indexes are
# 1-based while exec blocks are 0-based. "0:1"
# or "2:2~6" or "0:1,1:2~6,8;2:,3:24~30" "1,2"
# are valid values for the option. "3:" alone
# will be interpreted as, all the scans of the
# exec block#3. An scan index or a scan index
# range not preceded by an exec block index
# will be interpreted as, all the scans with
# such indexes in all the exec blocks. By
# default all the scans are considered.
ignore_time = False # All the rows of the tables Feed, History,
# Pointing, Source, SysCal, CalDevice,
# SysPower, and Weather are processed
# independently of the time range of the
# selected exec block / scan.
process_syspower = True # The SysPower table is processed if and only
# if this parameter is set to true.
process_caldevice = True # The CalDevice table is processed if and only
# if this parameter is set to true.
process_pointing = True # The Pointing table is processed if and only
# if this parameter is set to true.
process_flags = True # Create online flags in the FLAG_CMD sub-
# table.
tbuff = 0.0 # Time padding buffer (seconds)
applyflags = False # Apply the flags to the MS.
savecmds = False # Save flag commands to an ASCII file
outfile = ’’ # Name of ASCII file to save flag commands
verbose = False # Output lots of information while the filler
# is working
overwrite = True # Over write an existing MS
showversion = False # Report the version of asdm2MS being used
useversion = ’v3’ # Version of asdm2MS to be used (’v3’ (default,
# should work for all data))
async = False # If true the taskname must be started using
# importasdm(...)
If scans is set, then importasdm processes only the scans specified in the option’s value. This value is a semicolon separated list of scan specifications. A scan specification consists in an exec bock index followed by the character ’:’ followed by a comma separated list of scan indexes or scan index ranges. A scan index is relative to the exec block it belongs to. Scan indexes are 1-based while exec blocks’s are 0-based. The expressions
"2:2~6"
"0:1,1:2~6,8;2:,3:24~30"
"1,2"
"3:"
are all valid values for the selection. The "3:" selector will be interpreted as ’all the scans of the exec block 3’. An scan index or a scan index range not preceded by an exec block index will be interpreted as ’all the scans with such indexes in all the exec blocks’. By default all the scans are considered.
When process_flags=True the task will create online flags based on the Flag.xml, Antenna.xml and SpectralWindow.xml files and copy them to the FLAG_CMD sub-table of the MS. The flags will NOT be applied unless the parameter applyflags is set to True. Optionally, the flags can also be saved to an external ASCII file if savecmds is set to True.
If singledish=True, output data format is scantable (single-dish data format, see 8) instead of MS. In that case, you must specify name or id of the antenna that you want to obtain data. This can be done by using antenna parameter that is defined as a subparameter of singledish. For single-dish mode, only auto-correlation data are filled, i.e. ocorr_mode is forcibly set to ’ao’.
More information about CASA may be found at the
CASA web page
Copyright © 2010 Associated Universities Inc., Washington, D.C.
This code is available under the terms of the GNU General Public Lincense
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