Observation geometries for 1998 and 2011 observations. Red, dark blue, and sky blue disks represent Sun, Earth, and Uranus, respectively. Here, V_E1 and V_E2 represent the orbital velocity direction of Earth during 1998 and 2011 observations, respectively, and V_U1 and V_U2 represent the same for Uranus. Vector sizes do not represent their magnitudes, and the Sun and planet sizes are not to scale. LOS1 and LOS2 denote the lines of sight during 1998 and 2011 observations, respectively. IPH flow direction is considered to be constant during both the observation campaigns. Locations S and E in Uranus’ orbit represent southern summer solstice (1986) and northern spring equinox (2007), respectively, at Uranus.