Rotation measures of compact sources in the Canadian Galactic Plane Survey

The Canadian Galactic Plane Survey is providing new rotation measures (RMs) for compact extragalactic sources in the Galactic plane at a solid-angle density of roughly 1 source per square degree. To date, we have derived reliable RM values for 380 sources along lines of sight through the disk of the Galaxy in the first and second quadrants. The purpose is to provide a data set useful for studies of the magneto-ionic component of the Galactic interstellar medium ( ISM). We present the method used to obtain the measurements and the resulting RMs.