DISR

The Descent Imager/Spectral Radiometer (DISR) will make a range of imaging and spectral observations using several sensors and fields of view. By measuring the upward and downward flow of radiation, the radiation balance (or imbalance) of the thick Titan atmosphere will be measured. Solar sensors will measure the light intensity around the Sun due to scattering by aerosols in the atmosphere. This will permit the calculation of the size and number density of the suspended particles. Two imagers (one visible, one infrared) will observe the surface during the latter stages of the descent and, as the probe slowly spins, build up a mosaic of pictures around the landing site. There will also be a side-view visible imager to get a horizontal view of the horizon and the underside of the cloud deck. For spectral measurements of the surface, a lamp that will switch on shortly before landing will augment the weak sunlight.