hpx2gs

This IDL facility provides a means to turn a HEALPix map into a image that can be visualized with Google Earth or Google Skyas well as with Oculus VR headsets.

Location in HEALPix directory tree: src/idl/visu/hpx2gs.pro 

FORMAT

IDL> hpx2gs, File, [ Select, ] [ COORD_IN=, /HELP, KML=, PNG=, RESO_ARCMIN=, SUBTITLE=, TITLEPLOT=,+ most of cartview keywords$\ldots$ ]

QUALIFIERS

File

Required name of a FITS file containing the HEALPix map in an extension or in the image field, or name of an online variable (either array or structure) containing the HEALPix map (See note below); if Save is set : name of an IDL saveset file containing the HEALPix map stored under the variable data (default : none)

Select

Optional column of the BIN FITS table to be plotted, can be either – a name : value given in TTYPEi of the FITS file NOT case sensitive and can be truncated, (only letters, digits and underscore are valid) – an integer : number i of the column containing the data, starting with 1 (also valid if File is an online array) default:1 for full sky maps, 'SIGNAL' column for FITS files containing cut sky maps

KEYWORDS

COORD_IN=

1-character scalar, describing the input data coordinate system:
either 'C' or 'Q' : Celestial2000 = eQuatorial,
'E' : Ecliptic,
'G' : Galactic.
If set, it will over-ride the coordinates read from the FITS file header (when applicable). In absence of information, the input coordinates is assumed to be celestial.
The data will be rotated so that the output coordinates are Celestial, as expected by Google Sky

/HELP

Prints out the documentation header

KML=

Name of the KML file to be created (if the .kml suffix is missing, it will be added automatically). Used only by Google Earth and Google Sky. default:'hpx2googlesky.kml'

PNG=

Name of the PNG overlay file to be created. Only to be used if you want the filename to be different from the default (default: same as KML file, with a .png suffix instead of .kml)

RESO_ARCMIN=

Pixel angular size in arcmin (at the equator) of the cartesian map generated default:30

SUBTITLE=

information on the data, will appear in KML file GroundOverlay description field

TITLEPLOT=

information on the data, will appear in KML file GroundOverlay name field

/ASINH,

COLT=, FACTOR=, /FLIP, GLSIZE=, GRATICULE=, HBOUND=,

/HIST_EQUAL, IGLSIZE=, IGRATICULE=, /LOG, MAX=, MIN=,

/NESTED, OFFSET=,

OUTLINE=, POLARIZATION=, /PREVIEW,

/QUADCUBE, SAVE=, /SILENT,

TRUECOLORS=

those keywords have the same meaning as in cartview and mollview

DESCRIPTION

hpx2gs reads in a HEALPix sky map in FITS format or from a memory array and generates a cartesian (equirectangular) projection of it in a PNG file, as well as a Google Sky compatible KML file. Missing or unobserved pixels in the input data will be totally 'transparent' in the output file.

RELATED ROUTINES

This section lists the routines related to hpx2gs

see cartview

hpx2dm

turns Healpix maps into DomeMaster images

EXAMPLE:

map = findgen(48)

hpx2gs, map, kml='my_map.kml',title='my map in Google'

produces in my_map.kml and in my_map.png an image of the input map that can be seen with Google Sky. To do so, start GoogleEarth or GoogleSky and open my_map.kml. Under MacOSX, simply type open my_map.kml on the command line.