| Radio wave bending is caused by atmospheric refraction, which leads to the distance measured by radio navigation system different from the truth. Therefore, atmospheric refraction modification must be made in order to improve the accuracy of measurement.Atmospheric refraction profile can be retrieved from the atmospheric brightness temperature measured by dual-frequency millimeter wave radiometer and weather parameters measured by automatic weather station. In addition to the advantage of all-weather and real-time, radiometers can escape the influence of hypothesis of delamination, and accordingly the correction result has higher precision compared with traditional ways.The design of dual-frequency millimeter wave radiometer is discussed in detail in the dissertation. The experiment results are given also. The results indicate that the method of millimeter wave radiometer correction in the troposphere is feasible. And the correction precision depends on the accuracy of brightness temperature and the accuracy of correction model. Consequently, low side-band, high efficiency antenna and accurate correction models are preferred. |
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