Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/alfa/ealfa/meeting2/handouts/software_wf.ps Дата изменения: Sat May 13 00:11:11 2006 Дата индексирования: Sun Dec 23 03:35:03 2007 Кодировка: Поисковые слова: о п п

Software
for
Deep
Survey
.
How
useful
are
tools
developed
for
HIPASS
for
ALFA
surveys?
.
HIPASS
members
in
DEEP
working
group
.
Software
not
specific
to
DEEP
survey
.
Initial
assessment
byMartin
Zwaan
Wolfram
Freudling

Tools
developed
for
HIPASS
Livedata:
On­line/off­line
processing
software
.
removes
bandpass
.
calibrates
the
spectra
.
applies
doppler
tracking,
smoothes
and
baselines
the
spectra
.
has
an
excellent
capability
for
visualising
calibrated
spectra
Gridzilla:
takes
spectra
from
a
collection
of
bandpass­calibrated
measurement
sets
and
writes
a
3­plane
cube
Both
are
aips++
packages
(Solaris/Linux,
not
Mac)
See:
http://aips2.nrao.edu/docs/cookbook/cbvol3/node6.html
for
desciption
of
tasks
Both
were
specifically
designed
for
Parkes
Multibeam,
but
could
be
easily
modified
to
work
for
ALFA
Viewgraphs
prepared
byMartin
Zwaan
(ESO)

Livedata
GUI
scheduler
Bandpass
calibration
Multibeam reader
Data monitor

Gridzilla
GUI

On­line
monitoring
.
Monitor
display
#
livedata
.
Statistics tools
#
livedata
.
RFI id & removal
/ #
(median filtering removes some RFI)
.
NVSS cross reference
.
1 beam bandpass
#
livedata
.
1 beam spectra
#
livedata
.
Quick­look T­F maps
#
livedata
.
Quick­look X­Y maps
(maps made with gridzilla, not on­line)

Level I processing
.
Bandpass
subtraction
#
livedata
.
Continuum subtraction
#
by LUTHER (fits and subtracts templates)
.
Flux calibration
#
livedata
.
Higher level RFI excision
.
Astrometry
#
(not an issue for HIPASS...)
.
Gridding
#
gridzilla
.
Level 1 CLEANing
(HIPASS sources unresolved so no deconvolution. Need to do this for ALFA)
.
Level 1 spectra
#
livedata
.
Level 1 maps & cubes
maps & cubes only level II
.
Continuum catalogue
in progress (David Barnes) (level II)
.
Data validation process
#
livedata
.
Level 1 access tools
#
livedata
.
Level 1 documentation
#
see ATNF/HIPASS webpages
.
Level 1 software export
#
.
Level 1 archive
#

Level II processing
.
Level II CLEANing
(is required for ALFA)
.
Level II spectra
#
livedata
.
Level II maps
#
gridzilla
.
Level II cubes
#
gridzilla
.
Data validation
#
livedata
.
Level II archive
#
FITS cubes
.
Level II access tools
#
.
Level II documentation
#
.
Level II software export #
.
Portal to NVO
the HIPASS catalogue is VO compliant, the cubes are not

Level III Data & Software Tasks
.
Baseline fluctuations
#
livedata
.
Noise characteristics
#
livedata
.
Sidelobe
``cleaning'' schemes
#
livedata
.
Object finding algorithms
#
peak flux/wavelet (see Meyer et al 2004)
.
Template fitting
?
.
Injection of fake sources
#
lesson from HIPASS: need MANY! (see Zwaan
et al 2004)
.
Extended vs. point sources
#
not a big issue for HIPASS (see M04)
.
Detection documentation
#
M04 & Z04
.
Data validation process
?
.
HI source catalogue
#
.
Survey simulator
why?
.
ALFA simulator
.
Overlay tool
#
Drinkwater
et al in prep
.
Catalogue Xreference
tool
#
ditto
.
Toolkit documentation

Level
of
effort
to
convert
to
ALFA
.
``pskread''#
``alfareader''
--
Converts data to glish
format which can be
continuously read
.
Time dependent bandpass
estimate, depends on
observing strategy
.
Cleaning
.
RFI treatment
.
Modify line spread function by clever smoothing (convolution)

Issues
.
AIPS++ support?
.
Date rate Parkes: 1024ch * 2pols * 13 beams every 5 sec= 26* 1 kByes/sec
.
ALFA data rate: 8194 * 2pol * 7 beams ~ factor of 5 bigger than Parkes