The project objectives are the following:

• Completing the HIA in-flight absolute calibration The absolute calibration procedure assumes that energy and anode efficiency dependences are well described by the coefficients determined on ground, before launch. It is the standard in-flight calibration procedure, achieved by comparing the HIA data with the data provided by the WHISPER experiment on carefully selected magnetosheath intervals, for the HS section of the instrument, or solar wind intervals, for the LS sensitivity section. This objective will concentrate on HIA data after July 2009 and before November 2005 (HIA data between Nov. 2005 to Nov 2009 have already been calibrated at ISS before the start of CALYPSO).

• Statistical comparisons between HIA and WHISPER density data in various plasma environments Here all intervals, not just a selected subset, from certain time epoch(s) are considered for a statistical study. This objective provides important feed-back on the results obtained by the previous objective and documents the instrument performance in magnetospheric regimes not used for calibration.

• Anode and energy dependence of HIA in-flight efficiency This objective investigates the anode and energy dependence of HIA in-flight efficiency, aiming at improving the in-flight calibration task beyond the standard/absolute calibration procedure.

• In-flight calibration of He⁺⁺ measurements provided by HIA The goal of this objective is to calibrate in-flight the He⁺⁺ plasma moments provided by HIA when probing the solar-wind, a procedure that has not been performed so far.