RADAR
The Radio Detection and Ranging Instrument (RADAR) will produce maps of Titan's surface and measures the height of surface objects (like mountains and canyons) by bouncing radio signals off Titan's surface and timing their return. This is similar to listening for the echo of your voice in a large room to tell how wide the room is. Radio waves can penetrate the thick veil of haze surrounding Titan. In addition to bouncing radio waves, RADAR will listen for radio waves that Saturn or its moons may be producing.
RADAR can operate in three ways: imaging, altimetry, and radiometry. Each mode allows for the collection of different types of data, from straightforward imaging to three-dimensional modelling to passive collection of information, such as simply recording the energy emanating from a planet's surface.
RADAR uses Cassini's High Gain Antenna to communicate with Earth.