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We have developed a package of HEALPix based mathematical software, consisting
of Fortran90 and IDL source codes as well as documentation and
examples. Successful installation produces a set of facilities using standardised
FITS I/O interfaces
(http://heasarc.gsfc.nasa.gov/docs/software/fitsio)
as well as two Fortran90
libraries which users can link to their own applications.
Among the tasks performed by the components of the
HEALPix package are the
following:
Simulation of the full sky CMB temperature and polarisation maps
as realisations of random Gaussian fields, with an option to constrain
the realisation by prior information.
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Analysis of the full sky CMB temperature and polarisation maps
resulting in power spectra and/or spherical harmonic
coefficients. Relevant conventions are given in Appendix A.
Note that the convention used for polarization has been changed !.
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Global smoothing of whole sky maps with a Gaussian kernel.
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Degradation and upgrade of the resolution of discrete maps.
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Global searches on the maps for nearest-neighbours and
the maxima/minima of the discretised functions.
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Algebraic conversion of the maps between the RING and NESTED numbering
schemes, and mapping back and forth between positions on the sphere and
discrete pixel index space.
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Pixel queries for various geometrical shapes (discs, triangles, polygons ...)
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Visualisation of the HEALPix formatted sky maps in the
Mollweide, orthographic, cartesian cylindrical and gnomonic
projections of the whole sky or small areas of it.
The package includes documents which describe the installation
process, the Fortran 90
facilities, the IDL facilities and a large number of
subroutines contained in the library. It is
available to the scientific community at http://healpix.jpl.nasa.gov.
HEALPix is the format chosen by the WMAP
collaboration
to be used for the production
of sky maps (see
http://map.gsfc.nasa.gov/html/technical_info.html) from the mission data.
HEALPix software is widely used
for simulation work within both the LFI and HFI consortia of the Planck
collaboration (see
http://astro.estec.esa.nl/Planck/).
It is also being used to analyse the data provided by the balloon CMB missions
Boomerang
(see http://cmb.PHYS.cwru.edu/boomerang/
or
http://oberon.roma1.infn.it/boomerang/)
and Archeops (
http://archeops01.free.fr/main_archeops/index_english.html).
Eric Hivon
2010-06-18
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