2016ApJ...825..117B

We develop new techniques for estimating the fractional uncertainty ( { \mathcal F } ) in the projected planetary mass (m sin i) resulting from Keplerian fits to radial-velocity (RV) data sets of known Jupiter-class exoplanets. The techniques include (1) estimating the distribution of m sin i using projection, (2) detecting and mitigating chimeras, a source of systematic error, and (3) estimating the reduction in the uncertainty in m sin i if hypothetical observations were made in the future. We demonstrate the techniques on a representative set of RV exoplanets, known as the Sample of 27, which are candidates for detection and characterization by a future astrometric direct imaging mission. We estimate the improvements (reductions) in { \mathcal F } due to additional, hypothetical RV measurements obtained in the future. We encounter and address a source of systematic error, "chimeras," which can appear when multiple types of Keplerian solutions are compatible with a single data set.