Ideally the antenna should be mounted so that it is positioned in front of the pan tilt device – this mounting configuration minimizes torque.
Geo-pointing (GPM) functionality is built in to the E-series pan tilts, including the E46, D48E, D100E, and D300E models. However, geo-pointing and inertial stabilization (ISM) are not designed to work together at the same time. Geo-pointing is for fixed installations. A calibration is required to determine the position and heading of the pan tilt. Once the unit is moved to a new location, the calibration needs to be re-done. ISM is designed for use on moving platforms such as boats and vehicles, so GPM calibration would be lost if you tried to use both at the same time. GPM could be used when ISM is not active.
ISM units have reduced payload capacity due to the higher accelerations and speeds needed for stabilization.
For the (legacy) D46, as well as the D47 and D300 RF PTUs, a separate Geo-Pointing Module (GPM) is available.