| 摘要 |
PURPOSE:To reduce an outside dimension, a weight and a power consumption, and also to always execute an observation on a track, by using a multi-channel comparing noise source in common to each channel, and supposing a calibrating straight line in a low temperature area by a high temperature noise source. CONSTITUTION:When the connection of a switch 7 is switched from the side (2) to the side (3), a noise temperature T1 from a multi-channel high temperature noise source 13, and an noise temperature T2 of a standard noise source 5 are led to a receiver 10, when a switch 9 is at the side (a), and when said switch is at the side (3), respectively, and voltages V1, V2 being proportional to a temperature difference against comparing noise source 11, respectively are generated in the receiver 10. In this case, a temperature sensor is attached to the multi-channel high temperature noise source 13 and the standard noise source 5, and by monitoring it, input temperatures T1, T2 in the receiver 10 can be known. Also, when the switch 7 is connected to the side (2), a received antenna temperature can be derived by using the input temperatures T1, T2 and the voltages V1, V2 from an output voltage V which is generated in the receiver 10. |
