Modeling sky emission, through the interpretation of observational data and the development of software to simulate or predict sky emission, has been a significant fraction of my research since 2005.
Multicomponent Sky Models are designed as an answer to a number of needs:
A model of sky emission such as the Planck Sky Model is strongly connected to a compilation of observational data (maps, catalogues), which are interpreted in a coherent way, i.e. the model is 'data driven' preferably to 'physics driven', although the long term objective is to reconciliate the two in the best possible way. However, the PSM is not simply a collection of templates maps and catalogues of objects. Each sky emission is represented using a parametric model, using either physical parameters relevant to the various emission processes (e.g. cosmological parameters), but also empirical parameters used in phenomenological descriptions of the emissions.
The construction of a multi-component sky model is strongly connected to component separation and to the scientific interpretation of multifrequency observations, as illustrated below.
I am coordinating the development of the Planck Sky Model (PSM), a model based on observational data available prior to the launch of the Planck mission (data from IRAS, DIRBE, WMAP, etc.). This model can be used for simulating or predicting in a flexible way sky emission at frequencies ranging from a few GHz to a few THz, i.e. in the frequency range relevant for observations of the sky with the Planck mission.
Access the PSM website
Angelica de Oliveira-Costa's Global Sky Model
The CAMB software
CLASS, the Cosmic Linear Anisotropy Solving System