NPOESS Conical Microwave Imager/Sounder: issues and progress

The Integrated Program Office (IPO) of the National Polar-orbiting Operational Satellite System (NPOESS) is currently engaged in developing the next-generation microwave radiometer known as Conical Microwave Imager/Sounder (CMIS). CMIS will replace the current Special Sensor Microwave/Imager (SSM/I) and it s follow-on, the Special Sensor Microwave Imager Sounder (SSMIS). The first CMIS launch is currently scheduled for early 2009. The major design features of CMIS payload have been finalized. The baseline CMIS design has ´window´ channels at 6, 10, 19, 37, 89 and 166 GHz and ´sounding´ channels at 50-60, 23 and 183 GHz. It employs a dual-reflector system having a 2.2 m dish for 6.6 to 89 GHz and a smaller dish for high frequency channels. Both reflectors are oriented 180 degrees apart about the sensor spin axis. In addition, CMIS will have polarimetric capability at 10, 18, and 37 GHz, and will employ a suite of 40 Fast Fourier Transform (FFT) channels centered at 60.4347 GHz. CMIS will have a data rate of ∼500 kb/s, mass of ∼373 kg and will require ∼350 W of power.