tile_sky

Module Contents

Classes

Celpos	Information about how to convert command line strings to Python objects.
TwoFloats	Information about how to convert command line strings to Python objects.

Functions

arg_init()
prefix(word, pfx)
parset_init(fp, beamform_pa)
main()

Attributes

ster_to_sqdeg
explanation
description
label_help
interleave_help
script_name
FORMAT_FILE
FORMAT_CONSOLE
formatter_console
formatter_file
timestr
console

tile_sky.ster_to_sqdeg

tile_sky.explanation = Multiline-String

Show Value

"""

Script tile_sky
===============
This places observing tiles on the celestial sphere to optimise uniformity of sky coverage for a set of ASKAP
observations. The following options are supported:
1. The whole sky is tiled in the fashion described by Aaron Robotham (UWA):  (i) tiles are arranged along small circles
over a latitude band spanning the equator, and (ii) the polar regions are tiled using the same scheme but the small
circles are centred on poles shifted to the equator of the nominated coordinate system.
2. The whole-sky tiling can be masked by a user-supplied polygon: tiles wholly outside the polygon are excluded.
3. Tiles can be placed only over a region defined by a user-defined polygon; in some cases, this method gives a more
efficient distribution of tiles than the second option.

In all cases, tiles north of the telescope's northern limit are excluded.
For the 2nd and 3rd options, several polygons can be given. No check is made for overlap, which could result in
duplicates using option 3.

INPUTS
------
The tiling is controlled with these inputs:
1. -m lat1,lat2  the latitude margins of the small-circle section - (default values [-72,72])
2. -c {J2000,GALAC,MAGEL} specifies the coordinate frame - (default is J2000)
3. -r Origin of the tiling in the chosen coordinates (lon,lat) - (default is [0.0,0.0]
4. -p the beam spacing (pitch) - (default is 0.9 deg)
5. -n the name of the footprint - (default is square_6x6)

User supplied polygons must be presented in a text file with each line corresponding to one polygon described by a
coordinate pair (lon lat) for each vertex. For example, a strip survey along the equator could be:
-40.0 -3.0, 40.0 -3.0, 40.0 3.0, -40.0 3.0
Pairs are separated by commas; longitude and latitude are separated by spaces; values are decimal degrees in the
coordinate system specified by the -c option.

The script writes an observing parset file that holds the specifications of each tile wit positions given in J2000
coordinates suitable for ASKAP's control system. However, the script can perform the tiling in other coordinate frames:
currently the supported coordinates are equatorial  ("J2000"), Galactic  ("GALAC") or Magellanic ("MAGEL")
(for Magellanic coordinates see http://adsabs.harvard.edu/abs/2008ApJ...679..432N).

OUTPUTS
-------
The script produces results in several files:
 - <label>.parset  - observing parset; gives the required entries for each tile and its interleaves; at present this
    parset may need editing before submission as an ASKAP observation;
 - <label>.reg - ds9 region file that shows the tile locations and names;
 - <label>.ann - kvis annotations file that shows the tile locations and names on a kvis-displayed image;
 - <label>_footprint_ds9.sh v- shell script to produce plan-footprint.py output with ds9 overlays for each tile;
 - <label>_footprint_kvis.sh - shell script to produce plan-footprint.py output with kvis overlays for each tile.

"""

tile_sky.description = Multiline-String

Show Value

"""
This tiles the sky with tiles arranged along small circles over a declination band
within user-specified limits. Outside this, a polar-cap uses the same scheme but centred on the SCP
and limited in extent to minimise overlap with the dec-band section.


"""

tile_sky.label_help = Multiline-String

Show Value

"""
Name of region being tiled. This is used to name all auxilliary output files:
    kvis annotations file <LABEL>.ann
    plot file <LABEL>.png;
    Shell script for running footprint-plan.py on all tiles <LABEL>_footprint.sh;
    Observing parset <LABEL>.parset (can be overridden with the -o option).

The label is also used in naming fields in the parset.

"""

tile_sky.interleave_help = Multiline-String

Show Value

"""
If interleaving is selected (the default), each primary tile will be accompanied by
one or two additional tiles that place beam centres in the minima of the primary tile.
These interleaved tiles are also interleaved in the observing parset. So for a square
footprint, even numbered sources will be the primary 'A' position and odd numbered
the 'B'. For hexagonal patterns there are two additional tiles for each primary:
'B' and 'C'.

 """

tile_sky.script_name = 'tile_sky'

tile_sky.FORMAT_FILE = '%(asctime)s - %(name)s - %(levelname)s - %(message)s'

tile_sky.FORMAT_CONSOLE = '%(name)s - %(levelname)s - %(message)s'

tile_sky.formatter_console

tile_sky.formatter_file

tile_sky.timestr

tile_sky.console

tile_sky.arg_init()

class tile_sky.Celpos(option_strings, dest, nargs=None, **kwargs)

Bases: argparse.Action

Information about how to convert command line strings to Python objects.

Action objects are used by an ArgumentParser to represent the information needed to parse a single argument from one or more strings from the command line. The keyword arguments to the Action constructor are also all attributes of Action instances.

Keyword Arguments:

• option_strings – A list of command-line option strings which

  should be associated with this action.

• dest – The name of the attribute to hold the created object(s)

• nargs – The number of command-line arguments that should be

  consumed. By default, one argument will be consumed and a single value will be produced. Other values include:

  • N (an integer) consumes N arguments (and produces a list)

  • ‘?’ consumes zero or one arguments

  • ‘*’ consumes zero or more arguments (and produces a list)

  • ‘+’ consumes one or more arguments (and produces a list)

  Note that the difference between the default and nargs=1 is that with the default, a single value will be produced, while with nargs=1, a list containing a single value will be produced.

• const – The value to be produced if the option is specified and the

  option uses an action that takes no values.

• default – The value to be produced if the option is not specified.

• type – A callable that accepts a single string argument, and

  returns the converted value. The standard Python types str, int, float, and complex are useful examples of such callables. If None, str is used.

• choices – A container of values that should be allowed. If not None,

  after a command-line argument has been converted to the appropriate type, an exception will be raised if it is not a member of this collection.

• required – True if the action must always be specified at the

  command line. This is only meaningful for optional command-line arguments.

• help – The help string describing the argument.

• metavar – The name to be used for the option’s argument with the

  help string. If None, the ‘dest’ value will be used as the name.

__call__(parser, namespace, values, option_string=None)

class tile_sky.TwoFloats(option_strings, dest, nargs=None, const=None, default=None, type=None, choices=None, required=False, help=None, metavar=None)

Bases: argparse.Action

Information about how to convert command line strings to Python objects.

Action objects are used by an ArgumentParser to represent the information needed to parse a single argument from one or more strings from the command line. The keyword arguments to the Action constructor are also all attributes of Action instances.

Keyword Arguments:

• option_strings – A list of command-line option strings which

  should be associated with this action.

• dest – The name of the attribute to hold the created object(s)

• nargs – The number of command-line arguments that should be

  consumed. By default, one argument will be consumed and a single value will be produced. Other values include:

  • N (an integer) consumes N arguments (and produces a list)

  • ‘?’ consumes zero or one arguments

  • ‘*’ consumes zero or more arguments (and produces a list)

  • ‘+’ consumes one or more arguments (and produces a list)

  Note that the difference between the default and nargs=1 is that with the default, a single value will be produced, while with nargs=1, a list containing a single value will be produced.

• const – The value to be produced if the option is specified and the

  option uses an action that takes no values.

• default – The value to be produced if the option is not specified.

• type – A callable that accepts a single string argument, and

  returns the converted value. The standard Python types str, int, float, and complex are useful examples of such callables. If None, str is used.

• choices – A container of values that should be allowed. If not None,

  after a command-line argument has been converted to the appropriate type, an exception will be raised if it is not a member of this collection.

• required – True if the action must always be specified at the

  command line. This is only meaningful for optional command-line arguments.

• help – The help string describing the argument.

• metavar – The name to be used for the option’s argument with the

  help string. If None, the ‘dest’ value will be used as the name.

__call__(parser, namespace, values, option_string=None)

tile_sky.prefix(word, pfx)

tile_sky.parset_init(fp, beamform_pa)

tile_sky.main()