#
# stub function definition file for docstring parsing
#
[docs]def fixplanets(vis, field='""', fixuvw=False, direction='', refant='0', reftime='first'):
r"""
Changes FIELD and SOURCE table entries based on user-provided direction or POINTING table, optionally fixes the UVW coordinates
[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
Parameters
- vis_ (string) - Name of input visibility file
- field_ (variant='""') - Select field using field id(s) or field name(s)
- fixuvw_ (bool=False) - Recalculate Fourier-plane u,v,w coordinates
- direction_ (variant='') - If set, do not use pointing table but set direction to this value
- refant_ (variant='0') - Reference antenna name(s)
- reftime_ (string='first') - If using pointing table information, use it from this timestamp
.. _Description:
Description
The main purpose of this task is to correct observations which
were performed with correct pointing and correlation but for which
incorrect direction information was entered in the FIELD and
SOURCE table of the MS. This may be the case if the data is old
and there is no ephemeris table attached to the MS (in which case,
use **fixplanets** with the parameter *direction* set in order to
attach one), if improved ephemerides have become available, or
if a fixed direction is needed to allow concatenation (using
**fixplanets** as an alternative to **concat**).
If you actually want to change the phase center of the visibilties
in an MS, you should use task **fixvis**.
.. rubric:: Parameter descriptions
*vis*
Name of the input visibility set.
*field*
Field selection string.
*fixuvw*
Recalculates the uvw coordinates (default: False).
*direction*
If set, **fixplanets** doesn't use the pointing table but sets the
direction to this value.
default= '' (use pointing table); example: 'J2000 19h30m00
-40d00m00'.
The direction can either be given explicitly or as the path to a
JPL Horizons ephemeris text file (for an example of the format,
see directory data/ephemerides/JPL-Horizons/).
Alternatively, for most sources, the ephemeris file can also be
provided as mime format file, i.e., a saved email as obtained via
the following commands (The request function is only available in CASA 5.8):
::
import recipes.ephemerides.request as jplreq
jplreq.request_from_JPL(objnam='Mars', startdate='2012-01-01', enddate='2013-12-31',
date_incr='0.1d', get_axis_orientation=False,
get_axis_ang_orientation=True, get_sub_long=True,
use_apparent=False, get_sep=False,
return_address='YOUR_EMAIL_ADDESS',
mailserver='YOUR_MAIL_SERVER_ADDRESS')
.. note:: **NOTE**: Some mail clients may not save the JPL mail properly.
Confirmed to work in Thunderbird.
In cases where the source is not included in
recipes.ephemerides.request, use the following set of commands to
get the file in mime format for all sources:
- go to the `JPL ephemerides
webpage <http://ssd.jpl.nasa.gov/horizons.cgi>`__
- change the target body entry to the desired object
- click on 'batch-file' data in the special options section
- retrieve the command parameter, which is the 'code' for the
object (i.e., DES=C/2011 L4')
- send an email to horizons@ssd.jpl.nasa.gov, with JOB as
subject, and in the body:
::
!$$SOF
COMMAND= 'DES=C/2011 L4'
CENTER= '500@399'
MAKE_EPHEM= 'YES'
TABLE_TYPE= 'OBSERVER'
START_TIME= '2014-06-28'
STOP_TIME= '2014-07-01'
STEP_SIZE= '1 m'
CAL_FORMAT= 'CAL'
TIME_DIGITS= 'MINUTES'
ANG_FORMAT= 'DEG'
OUT_UNITS= 'KM-S'
RANGE_UNITS= 'AU'
APPARENT= 'AIRLESS'
SOLAR_ELONG= '0,180'
SUPPRESS_RANGE_RATE= 'NO'
SKIP_DAYLT= 'NO'
EXTRA_PREC= 'NO'
R_T_S_ONLY= 'NO'
REF_SYSTEM= 'J2000'
CSV_FORMAT= 'NO'
OBJ_DATA= 'YES'
EMAIL_ADDR = 'amoullet@nrao.edu'
QUANTITIES= '1,17,19,20,24,14,15'
!$$EOF
where COMMAND, START_TIME, STOP_TIME, STEP_SIZE and EMAIL_ADDR
must be adapted to the case. See the Examples tab for how to use
the returned ephemeris.
*refant*
If using pointing table information, use it from this antenna.
default: 0 (antenna id 0); examples: 'DV06' (antenna with name
DV06); 3 (antenna id 3).
*reftime*
If using pointing table information, use it from this timestamp.
default: 'first'; examples: 'median' will use the median timestamp
for the given field using only the unflagged maintable rows;
'2012/07/11/08:41:32' will use the given timestamp (must be within
the observaton time).
.. _Examples:
Examples
To look up the pointing direction from antenna 0 for field 'Titan'
in the POINTING table based on the first timestamp in the main
table rows for this field, write this direction in the FIELD and
SOURCE tables, and then recalculate the UVW coordinates for this
field:
::
fixplanets(vis='uid___A002_X1c6e54_X223.ms', field='Titan', fixuvw=True)
To attach the ephemeris table 'Titan_55438-56292dUTC.tab' to field
'Titan' and then recalculate the UVW coordinates for this field:
::
fixplanets(vis='uid___A002_X1c6e54_X223.ms', field='Titan',
fixuvw=True, direction='Titan_55438-56292dUTC.tab')
To set the directions for field 'Titan' in the FIELD and SOURCE
table to the given direction and not recalculate the UVW
coordinates; this can be useful for several purposes, among them
preparing a concatenation of datasets. (Only fields with the same
direction will be recognised as identical.):
::
fixplanets(vis='uid___A002_X1c6e54_X223.ms', field='Titan',
fixuvw=False, direction='J2000 12h30m15 -02d12m00')
To use an ephemeris file returned from JPL via the email query
described in the Description tab in the case where the source is
unavailable via recipes.ephemerides.request, first copy the entire
email received from JPL into a file with a .eph extension (for
example, "target.eph"), and then attach the ephemeris using
**fixplanets**:
::
fixplanets(vis='uid___A002_X1c6e54_X223.ms', fixuvw=True,
direction='target.eph')
.. _Development:
Development
No additional development details
.. _Details:
Parameter Details
Detailed descriptions of each function parameter
.. _vis:
| ``vis (string)`` - Name of input visibility file
| Default: none
| Example: vis='ngc5921.ms'
.. _field:
| ``field (variant='""')`` - Select field using field id(s) or field name(s)
| Default: '' (all fields)
|
| Use 'go listobs' to obtain the list id's or
| names. If field string is a non-negative integer,
| it is assumed a field index, otherwise, it is
| assumed a field name.
| Examples:
| field='0~2'; field ids 0,1,2
| field='0,4,5~7'; field ids 0,4,5,6,7
| field='3C286,3C295'; field named 3C286 and
| 3C295
| field = '3,4C*'; field id 3, all names
| starting with 4C
.. _fixuvw:
| ``fixuvw (bool=False)`` - Recalculate Fourier-plane u,v,w coordinates?
| Default: False
| Options: False|True
.. _direction:
| ``direction (variant='')`` - If set, do not use pointing table but set direction to
| this value
| Default: '' (use pointing table)
| Example: 'J2000 19h30m00 -40d00m00'
| The direction can either be given explicitly or
| as the path to a JPL Horizons
| ephemeris. Alternatively, the ephemeris table can
| also be provided as mime format file. For more
| information, see the task pages of fixplanets in
| CASA Docs (https://casa.nrao.edu/casadocs/).
.. _refant:
| ``refant (variant='0')`` - Reference antenna name(s); a prioritized list may be
| specified
| Default: 0 (antenna ID 0)
| Examples:
| refant='4' (antenna with index 4)
| refant='VA04' (VLA antenna #4)
| refant='EA02,EA23,EA13' (EVLA antenna EA02,
| use EA23 and EA13 as alternates if/when EA02
| drops out)
| Use taskname=listobs for antenna listing
.. _reftime:
| ``reftime (string='first')`` - If using pointing table information, use it from this
| timestamp
| Default: 'first'
| Examples:
| * 'median' will use the median timestamp for
| the given field using only the unflagged
| maintable rows
| * '2012/07/11/08:41:32' will use the given
| timestamp (must be within the observaton
| time)
"""
pass