GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  ASTRO::TELESCOPE (3)

.ds Aq ’

NAME

Astro::Telescope - class for obtaining telescope information

CONTENTS

SYNOPSIS



  use Astro::Telescope;

  $tel = new Astro::Telescope( UKIRT );

  $latitude = $tel->lat;
  $longitude = $tel->long;
  $altitude = $tel->alt;

  %limits = $tel->limits;

  @telescopes = Astro::Telescope->telNames();



DESCRIPTION

A class for handling properties of individual telescopes such as longitude, latitude, height and observational limits.

METHODS

    Constructor

<B>newB> Create a new telescope object. Takes the telescope abbreviation as the single argument.



  $tel = new Astro::Telescope( VLA );



An argument must be supplied. Returns undef if the telescope is not recognized.

If more than one argument is supplied the assumption is that the user is supplying telescope details. In that case, Name and Long must be supplied, and either the geodetic latitude and altitude (Lat and Alt — but if Alt is not supplied it will default to zero and this class will issue a warning), the geocentric latitude and distance (GeocLat and GeocDist), or the parallax coefficients (Parallax) must be supplied. Latitudes and longitudes must be given in radians, altitude and distance in metres, and the parallax constants in units of Earth radii.



  $tel = new Astro::Telescope(telescope);
  $tel = new Astro::Telescope(Name => JCMT, Long => $long, Lat => $lat );



    Accessor Methods

<B>nameB> Returns the abbreviated name of the telescope. This is the same as that given to the constructor (although it will be upper-cased).

The object can be reconfigured to a new telescope by supplying a new abbreviation to this method.



  $tel->name(JCMT);



The object will not change state if the name is not known.

<B>fullnameB> Returns the full name of the telescope. For example, if the abbreviated name is JCMT this will return JCMT 15 metre.
<B>obscodeB> Returns or sets the IAU observatory code as listed at http://cfa-www.harvard.edu/iau/lists/ObsCodes.html. The object will not change state if the observatory code is not known.
<B>longB> Longitude of the telescope (east +ve). By default this is in radians.

An argument of d or s can be supplied to retrieve the value in decimal degrees or sexagesimal string format respectively.



 $string = $tel->long("s");



<B>latB> Geodetic latitude of the telescope. By default this is in radians.

An argument of d or s can be supplied to retrieve the value in decimal degrees or sexagesimal string format respectively.



  $deg = $tel->lat("d");



<B>altB> Altitude of the telescope in metres above mean sea level.
<B>parallaxB> Return the parallax constants, rho*sin(phi’) and rho*cos(phi’), where rho is the geocentric radius in Earth radii and phi’ is the geocentric latitude. Returned as a hash where ’Par_C’ is rho*sin(phi’) and ’Par_S’ is rho*cos(phi’).



  @parallax = $tel->parallax;



<B>geoc_latB> Return the geocentric latitude. By default this is in radians.

An argument of d or s can be supplied to retrieve the value in decimal degrees or sexagesimal string format respectively.



  $deg = $tel->geoc_lat("d");



<B>geoc_distB> Return the distance from the centre of the Earth. By default this is in metres.



  $geoc_dist = $tel->geoc_dist;



<B>obsgeoB> Return the cartesian coordinates of the observatory. These are the form required for specifying coordinates in the FITS OBSGEO-X, OBSGEO-Y and OBSGEO-Z header items.



  ($x, $y, $z) = $tel->obsgeo;



Values are returned in metres.

<B>limitsB> Return the telescope limits.



  %limits = $tel->limits;



The limits are returned as a hash with the following keys:
type Specifies the way in which the limits are specified. Effectively the telescope mount. Values of AZEL (for altaz telescopes) and HADEC (for equatorial telescopes) are currently supported.
el Elevation limit of the telescope. Value is a hash with keys max and min. Units are in radians. Only used if type is AZEL.
ha Hour angle limit of the telescope. Value is a hash with keys max and min. Units are in radians. Only used if type is HADEC.
dec Declination limit of the telescope. Value is a hash with keys max and min. Units are in radians. Only used if type is HADEC.

Only some telescopes have limits defined (please send patches with new limits if you know them). If limits are not available for this telescope limits corresponding to above the horizon are returned.

If limits have been explicitly associated with this object using the setlimits method then those limits will be returned.

<B>setlimitsB> This method allows limits for this telescope object to be set explicitly. The contents of the limits hash must be those described by the limits method and will be returned by the limits method). Limits set in this way will override built-in limits.



  $tel->setlimits( %limits );



Limits will be cleared if the object is reconfigured (eg by setting the obscode).

    Class Methods

<B>telNamesB> Obtain a sorted list of all supported telescope names.



  @names = Astro::Telescope->telNames;



Currently only returns the PAL names, and only if Astro::PAL is available. If it is not available, return an empty list.

REQUIREMENTS

The list of telescope properties is currently obtained from those provided by PAL (Astro::PAL) and also from the Minor Planet Center (http://www.cfa.harvard.edu/iau/lists/ObsCodes.html).

AUTHORS

Tim Jenness <t.jenness@jach.hawaii.edu>, Brad Cavanagh <b.cavanagh@jach.hawaii.edu>

COPYRIGHT

Copyright (C) 2007, 2008, 2010, 2012 Science and Technology Facilities Council. Copyright (C) 1998-2005 Particle Physics and Astronomy Research Council. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
Search for    or go to Top of page |  Section 3 |  Main Index


perl v5.20.3 ASTRO::TELESCOPE (3) 2016-03-17

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.