There are several synonyms for the term "SSMIMAGER SOUNDER" in the field of remote sensing. One such synonym is "spaceborne synthetic aperture radar" (SAR), which refers to a type of imaging radar system mounted on satellites. SAR provides high-resolution images of the Earth's surface, and is widely used for various applications including land mapping and monitoring. Another synonym for SSMIMAGER SOUNDER is "passive microwave radiometer". These instruments measure the natural radiation emitted by the Earth's surface and atmosphere at microwave frequencies. They are particularly useful for studying atmospheric phenomena such as rainfall, cloud cover, and sea surface temperatures.