The datasets contain the reflector height measurements at Alert (2012-2017), Resolute Bay (2003-2014), Repulse Bay (2014-2017), Baker Lake (2010-2017), and Iqaluit (2010-2017) in northern Canada. Reflector height refers to the vertical distance between GPS antenna and reflecting surface, which is measured by GPS Interferometric Reflectometry. Each file, or dataset, is named by the site name, and it contains the variables 'year', 'day of year', 'reflector height', and 'uncertainty'. The units of reflector height and uncertainty are meters.