Interferometric measurement of tropospheric phase fluctuations at 86 GHz on antenna spacings of 24 m to 288 m

Measurements with the IRAM interferometer of tropospheric phase fluctuations at 86 MHz, on baselines 24-288 m, are reported. The data are used to derive phase structure function vs. baseline length, Allan variance and one-dimensional temporal phase power spectra. On average, the phase variance has a (baseline) 1.42 dependence, with the power law index changing between day and night. The one-dimensional phase power spectra vary with temporal frequency f as f -2.1 . The Fourier transform of the phase time series on a single baseline gives the approximate phase behaviour on other baselines