MTS
Millimeter-Wave Temperature Sounder

The Millimeter-Wave Temperature Sounder (MTS) was an airborne microwave radiometer developed by the Massachusetts Institute of Technology (MIT). It consisted of two radiometers that measure brightness temperature for precipitation and atmospheric temperature profiling. One radiometer was an eight-channel scanning spectrometer centered on the 118.75 GHz oxygen line. It had a 7.5-degree beamwidth and an integration time of 224 ms per spot, resulting in a 0.5 K resolution. The second radiometer was a single-channel nadir-viewing system operating from 52 to 56 GHz with a 10-degree beamwidth. MTS was replaced by the NPOESS Aircraft Sounder Testbed Microwave Radiometer (NAST-M).