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تسجيل مستخدم جديدRadar Absorption, Basal Reflection, Thickness, and Polarization Measurements from the Ross Ice Shelf
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Radio-glaciological parameters from Moores Bay, in the Ross Ice Shelf, have been measured. The thickness of the ice shelf in Moores Bay was measured from reflection times of radio-frequency pulses propagating vertically through the shelf and reflecting from the ocean, and is found to be $576pm8$ m. Introducing a baseline of 543$pm$7 m between radio transmitter and receiver allowed the computation of the basal reflection coefficient, $R$, separately from englacial loss. The depth-averaged attenuation length of the ice column, $<L >$ is shown to depend linearly on frequency. The best fit (95% confidence level) is $<L( u) >= (460pm20)-(180pm40) u$ m (20 dB/km), for the frequencies $ u=$[0.100-0.850] GHz, assuming no reflection loss. The mean electric-field reflection coefficient is $sqrt{R}=0.82pm0.07$ (-1.7 dB reflection loss) across [0.100-0.850] GHz, and is used to correct the attenuation length. Finally, the reflected power rotated into the orthogonal antenna polarization is less than 5% below 0.400 GHz, compatible with air propagation. The results imply that Moores Bay serves as an appropriate medium for the ARIANNA high energy neutrino detector.
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