The newer handsets have GPS tracking available in them. This is a good option if you do not want to purchase a standalone device but the tracking will not be as accurate or as robust, but does offer a cost effective way to track a user who is carrying a newer model of satellite phone.
This offers the best quality tracking information as this is primarily what these devices are designed for. With high grade GPS tracking modules ands streamlined transmission systems these units can obtain their fix more rapidly than a handset might be able to.
There standalone tracking units that can be used for vehicles or there are simple devices that run off batteries that can be preconfigured and just attached to a suitable location on the vehicle to provide a cost effective method for tracking vehicles outside of terrestrial coverage.