A scatterometer is a specialized instrument used to measure the scattering properties of surfaces. It is commonly used in remote sensing applications to gather important information about the earth's surface. There are a number of synonyms that can be used to refer to a scatterometer, including radiometer, reflectometer, and backscatterometer. These terms all describe instruments that are designed to measure the amount of reflected radiation from a surface. Other synonyms for scatterometer include radar altimeter, microwave sensor, and SAR (Synthetic Aperture Radar). Each of these terms refers to specific applications of the technology, but all are related to the measurement of scattering properties of a surface in remote sensing applications.