Sounder (passive)
"An instrument that measures vertical distributions of atmospheric parameters such as temperature, pressure, and composition from multispectral information." (National Aeronautics and Space Administration, 2018)
Sources
"Remote Sensors". Earthdata, National Aeronautics and Space Administration. Last modified December 11, 2018.
https://earthdata.nasa.gov/user-resources/remote-sensors.
Accessed February 13, 2019.