def get_ls(omega_list):
    """Return the array of the Solar longitude of each OMEGA/MEx observation in omega_list.

    Parameters
    ==========
    omega_list : array of OMEGAdata
        The input array of OMEGA observations.
    
    Returns
    =======
    ls : ndarray
        The array of the omega_list Ls.
    """
    ls = []
    for omega in omega_list:
        ls.append(omega.ls)
    return ls