| Paper: | TU-A2.2 |
| Session: | New Concepts in Radiometry II |
| Time: | Tuesday, March 27, 11:00 - 11:20 |
| Presentation: |
Oral
|
| Topic: |
Current and future satellite missions: |
| Title: |
TEMPEST-D Millimeter-wave Radiometers |
| Authors: |
Todd Gaier; NASA Jet Propulsion Laboratory | | |
| | Sharmila Padmanabhan; NASA Jet Propulsion Laboratory | | |
| | Boon H. Lim; NASA Jet Propulsion Laboratory | | |
| | Alan Tanner; NASA Jet Propulsion Laboratory | | |
| | Robert Stachnik; NASA Jet Propulsion Laboratory | | |
| | Richard Cofield; NASA Jet Propulsion Laboratory | | |
| | Robert Jarnot; NASA Jet Propulsion Laboratory | | |
| | Shannon Brown; NASA Jet Propulsion Laboratory | | |
| | Steven C. Reising; Colorado State University | | |
| | Venkatachalam Chandrasekar; Colorado State University | | |
| | Wesley Berg; Colorado State University | | |
| | Christian D. Kummerow; Colorado State University | | |
| Abstract: |
The TEMPEST-D instrument is a five-frequency millimeter-wave radiometer capable of observing thermal radiation from the Earth scene at 89, 165, 176, 180, and 182 GHz. The direct-detection architecture of the radiometer, employed for the first time at these frequencies, reduces the system power consumption and eliminates the need for a local oscillator, reducing complexity. The architecture relies upon InP monolithic microwave integrated circuits (MMIC) amplifiers developed in collaboration with Northrop-Grumman Corp. The instrument includes an ambient blackbody calibration target and a scanning reflector. The reflector scans in the cross-track direction so that the TEMPEST-D feedhorn and receiver view first the blackbody calibration target, then the Earth scene over a range of nadir angles from -45° to +45°, and finally cold space (CMB of 2.7 K), enabling precision end-to-end calibration of the millimeter-wave receivers every 2 second scan cycle.
Two TEMPEST-D instruments have been built and undergone environmental testing. The first flight unit has been delivered to Blue Canyon Technologies for integration into the 6U spacecraft, and is scheduled for launch in May 2018. Additional testing is performed at the spacecraft level. We will present the radiometer performance results through the battery of environmental and characterization tests. These data form the basis for the final TEMPEST-D pre-launch calibration. Data presented will include bandpass measurements (including those performed from antennna through detection), receiver linearity, receiver noise, antenna pattern tests, back-lobe contamination, spacecraft thermal vacuum and stability through vibration testing. From these data we will estimate on-orbit performance of noise equivalent temperature difference (NEDT) as well as simulated imagery. |
