  Pulsars are promising targets for the first detection of continuous
gravitational waves (CWs) by the LIGO-Virgo-KAGRA (LVK) Collaboration. Targeted
searches leverage critical information derived from continued monitoring of
pulsars related to the spin evolution, astrometry, and binary orbit. This
information maximizes the probability to detect CW signals using full coherent
methods. The 5-vector method is one of the three pipelines used by the LVK
Collaboration for the targeted search of CWs from known pulsars. In this
letter, we describe the first implementation and test of an heterodyne method
to correct the orbital Doppler effect for pulsars in binary systems for the
5-vector targeted search.
