  High harmonic spectroscopy has the potential to combine attosecond temporal
with sub-Angstrom spatial resolution of the early nuclear and multielectron
dynamics in molecules. It involves strong field ionization of the molecule by
the IR laser field followed by time-delayed recombination of the removed
electron with the molecular ion. The time-delay is controlled on the attosecond
time scale by the oscillation of the IR field and is mapped into the harmonic
number, providing a movie of molecular dynamics between ionization and
recombination. One of the challenges in the analysis of high harmonic signal
stems from the fact that the complex dynamics of both ionization and
recombination with their multiple observables are entangled in the harmonic
signal. Disentangling this information requires multidimensional approach,
capable of mapping ionization and recombination dynamics into different
independent parameters. We suggest multidimensional high harmonic spectroscopy
as a tool for characterizing of ionization and recombination processes
separately allowing for simultaneous detection of both the ionization delays
and sub-cycle ionization rates. Our method extends the capability of the two
dimensional (2D) set-up suggested recently by Shafir et al on reconstructing
ionization delays, while keeping the reconstruction procedure as simple as in
the original proposal. The scheme is based on the optimization of the high
harmonic signal in orthogonally polarized strong fundamental and relatively
weak multicolour control fields.
