NSSDCA ID: 1972-097A-08
Mission Name: Nimbus 5The Nimbus 5 Temperature-Humidity Infrared Radiometer (THIR) was designed to detect emitted thermal radiation in both the 10.5- to 12.5-micrometer region (IR window) and the 6.5- to 7.0-micrometer region (water vapor). The window channel measured cloudtop temperatures during both day and night. The other channel operated primarily at night to map the water vapor distribution in the upper troposphere and stratosphere. Sensor data from these two channels were primarily used to support the other more sophisticated meteorological experiments on board Nimbus 5. The instrument consisted of a 12.7-cm Cassegrain system, a scanning mirror common to both channels, a beam splitter, filters, and two germanium-immersed thermistor bolometers. In contrast to TV, no image was formed within the radiometer. Incoming radiant energy was collected by a flat scanning mirror inclined at 45 deg to the optical axis. The mirror rotated at 48 rpm and scanned in a plane perpendicular to the spacecraft velocity. The energy was focused on a dichromatic beam splitter, which divided the energy spectrally and spatially into the two channels. Both channels of the THIR sensor transformed the received radiation into electric outputs (voltages), which were recorded on magnetic tape for subsequent playback to a ground acquisition station. For more detailed information, see Section 2 in "The Nimbus 5 User's Guide" (TRF B14758). The THIR world montages were presented in "The Nimbus 5 Data Catalog" (TRF B17697). Both documents are available from NSSDC. A similar experiment was flown on Nimbus 4, 6, and 7.
Mass: 7.6 kg
Power (avg): 6 W
Bit rate (avg): 2 kbps
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Mr. Andrew W. McCulloch | Principal Investigator | NASA Goddard Space Flight Center |