To date, about 17 hot Jupiters have been directly detected by photometric and/or spectroscopic observations.
Only 2 of them, however, are non-transiting hot Jupiters and the rest are all transiting ones. Since non-transiting
hot Jupiter systems are analogs of high contrast binaries, optical/infrared long baseline interferometers can resolve
them and detect the planets if highly stable and precise closure phase measurements are obtained. Thus, this is
a good opportunity for optical/infrared interferometers to contribute to the field of exoplanet characterization.
To reach this goal, detailed calibration studies are essential. In this paper, we report the first results of our
closure phase calibration studies. Specifically, we find strong closure phase drifts that are highly correlated with
target positions, i.e., altitude and azimuth angle. The correlation is stronger with altitude. Our experiments
indicate that the major cause of the drifts is probably longitudinal dispersion. We are able to find a strategy with
multiple approaches to reduce this effect, and are able to model the closure phase drift with a quadratic function
of both altitude and azimuth. We then use this model to calibrate the drifts, and test this new calibration scheme
with the high contrast binary ε Per. Although we can find a better orbital solution with this new method, we
have also found difficulties to interpret the orbit of ε Per, which may stem from possible mis-calibrations or the
influence of the third component in the system. More investigations are definitely necessary to address this issue
and to further confirm our calibration strategy.