| 摘要 |
PURPOSE:To reduce the outer shape dimension, wt. and power consumption of a radiometer, by using a multichannel comparing noise source in the correction of the high temp. side of a multichannel microwave radiometer and making it possible to use said noise source in common to each channels. CONSTITUTION:When the switch SW8 of a channel chB is connected to a (3)-side, the noise temp. of a multichannel comparing noise source B is guided to a receiver 10 and voltage V0 is generated in the receiver 10. Next, the switch SW8 of the channel chB is changed over from the (3)-side to a (2)-side and, when the switch SW7 of a channel chA is in the (3)-side, correction temp. T1 is guided to the receiver from a dummy load 11 and, when in the (2)-side, the temp. TA of an antenna 1 is guided to the receiver 10 to respectively generate voltages V1, V. Temp. sensors are attached to the noise source 13 and the dummy load 11 to obtain respective input temp. T0 and T1 of the receiver 10. The temp. TA can be calculated from a predetermined formula by using temps. T0, T1 and voltages V0, V1, V. As mentioned above, the noise source 13 is used in a high temp. side correction source to reduce the standard noise source and correction source change-over switch of each channel and, because the noise source 13 is used in common to each channel, one comparing noise can be reduced.
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