| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a radiometer by which a low temperature and a high temperature can be calibrated without using an independent reflector, for low-temperature calibration, and a high-temperature calibration source by a method wherein a primary radiator and a reflector are cooled by a refrigerator or heated by a heater and a low- temperature calibration signal or the high-temperature calibration signal is obtained. SOLUTION: In an observation operation, noise radio waves radiated from the earth 12 are guided to a primary radiator 5 by using a reflector 2 for observation, they are complified, detected and integrated by a receiver 6 which is cooled inside a heat-insulating container 10, an they are sent out to the ground as an observation signal via a signal processor 7. When a low temperature is calibrated, the thermal noise of the primary radiator 5 and that of a reflector 14a are made equivalent to the physical temperature of the primary radiator and the reflector which are cooled by a refrigerator 9, and radio waves at, e.g. about 4K are input to the primary radiator 5 as a low-temperature calibration signal so as to be sent out to the ground. In addition, when a high temperature is calibrated, the temperature of a reflector 14b is controlled by a heater, and radio waves corresponding to a physical temperature at about 300K are input to the primary radiator 5 as a high-temperature calibration signal so as to be sent out to the ground.</p> |
