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tokens: i and inclination do not affect the derived ephemeris in this paper. 4. PROSPECTS FOR GWS DETECTABILITY 4.1. Precision Estimates Throughout Advanced LIGO (aLIGO)/VIRGO (AdV) Observations Observing runs for GW searches are planned to commence in 2015, and will run through to 2022+. Estimated run duration for 2015, 2016–17 and 2017–18, are 3, 6, and 9 months, respectively. Starting from 2019, more extended runs are expected take place with aLIGO and AdV per every year. In addition, LIGO India is also expected be included in the observing schedule from 2022 onwards (LIGO Scientific Collaboration et al. 2013 ). The inferior conjunction value for the future GW searches ( T n ) will depend on the uncertainties on both T 0 and P orb when aLIGO/VIRGO observations commence. We consider here how the error on T 0 may be projected in time to any given epoch. Given the epoch for inferior conjunction, T n = nP orb + T 0 , following Galloway et al. ( 2014 ), we derive the projected uncertainty for T n aswhere and are the uncertainties in the P orb and T 0 , respectively, and is the cross-term of the covariance matrix. Substituting the values from Table 2 , we express the error on T n as follows: Here, is the uncertainty in the epoch of inferior conjunction at the time of t in days since T 0 . The evolution of is shown as a function of time in Figure 3 . In the absence of additional epochs of observations, term will grow linearly due to the factor, 4.1× day. The effective uncertainty will grow approximately as a function of time, 2× in 2018 and 3× or greater in/after 2022 compared the current error level. Figure 3. Projected uncertainty throughout the aLIGO observing period (shaded regions) is plotted as a function of time. The solid line denotes the approximately linear growth of the effective error throughout the aLIGO observing period (from 2015 onwards) in the absence of the additional epochs of optical data. The open squares describe the approximate effect on the additional observing epochs and the T 0 uncertainty is represented by the dotted curves. The estimated orbital period uncertainty ( σP orb ) is denoted by a dashed line. The above estimated values show that additional epochs of RV measurements will be needed to further refine the system parameters in order to improve the future GW searches. Based on the following assumptions, we also carried out simulations to estimate the effect of additional epochs of RV measurements. First, that the uncertainty on T 0 decreases as the total number of observations increases. Second, that the uncertainty on P orb decreases as the total span of the observations increases. We generated 6 epochs of 100 simulated radial velocity measurements in total. We considered each observing epoch to consist of 15 random observations of LT between 2015 and 2025. We have estimated the parameter uncertainties by combining all existing data with the simulated 100 RV measurements. Simulations allow us to improve the uncertainty