Faraday rotation measurement method and apparatus
Abstract
A method and device for measuring Faraday rotation of a received RF signal is described. A simultaneous orthogonal polarization receiver compensates for a 3 db loss due to splitting of a received signal into left circular and right circular polarization channels. The compensation is achieved by RF and modulation arraying utilizing a specific receiver array which also detects and measures Faraday rotation in the presence or absence of spin stabilization effects on a linear polarization vector. Either up-link or down-link measurement of Faraday rotation is possible. Specifically, the Faraday measurement apparatus utilized in conjunction with the specific receiver array provides a means for comparing the phase of a reference signal in the receiver array to the phase of a tracking loop signal related to the incoming signal, and comparing the phase of the reference signal to the phase of the tracking signal shifted in phase by 90 degrees. The averaged and unaveraged signals, are compared, the phase changes between the two signals being related to Faraday rotation.
- Publication:
-
National Aeronautics and Space Administration Report
- Pub Date:
- October 1981
- Bibcode:
- 1981nasa.reptV....B
- Keywords:
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- Antenna Components;
- Faraday Effect;
- Measuring Instruments;
- Modulation;
- Polarization (Waves);
- Signal Reception;
- Arrays;
- Optical Measurement;
- Patents;
- Radio Receivers;
- Spacecraft Instruments;
- Instrumentation and Photography