  This paper presents a new algorithm, TRIMOR, to analyse multi-order spectra
of triple systems. The algorithm is an extension of TRICOR, the
three-dimensional correlation technique that derives the radial velocities of
triple stellar systems from single-order spectra. The combined correlation
derived from many orders enables the detection and the measurement of radial
velocities of faint tertiary companions. The paper applied TRIMOR to the
already available spectra of HD188753, a well known triple system, yielding the
radial velocities of the faintest star in the system. This rendered the close
pair of the triple system a double-lined spectroscopic binary, which led to a
precise mass-ratio and an estimate of its inclination. The close-pair
inclination is very close to the inclination of the wide orbit, consistent with
the assertion that this triple system has a close to coplanar configuration.
