In most research fields, notwithstanding some outstanding results, polarimetry is still too often overlooked. The action will aim at promoting polarization as an invaluable tool to obtain a wealth of information about astrophysical bodies in our Solar System and beyond. With the benefit of the COST legitimacy, the Actionwill recommend to the European Space Agency, the European Southern Observatory, national space agencies, European industry and policy makers the development and addition of polarimeters in future ground-based observatories and space missions.

The current state of European polarization research faces a lack of interaction between communities working on different objects and/or in different wavelength domains. Under the COST umbrella, the Action will set up the first network of polarization experts in many disciplines and over a wide range of the electromagnetic spectrum, foster multi-wavelength and cross-disciplinary collaborations, and make Europe the world leader in all fields of polarimetric science.