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Turbulence data for the International Turbulence Comparison Experiment (ITCE) held at Conargo, N.S.W. (35" 18' S.-145"lO' E.) during October, 1976 are analysed.The standard deviation (s/2)1/2 and covariance w's' measured by a number of instruments and instrument arrays have been compared& assess their field performance and calibration accuracy. Satisfactory agreement, i.e. typically 5% for (s")~/' (except in humidity) and of the order of 20% for n, was achieved, but only after consideration of:(1) Instrumental response at high frequencies.(2) Flow distortion induced by instruments and supporting structures.(3) Spatial separation of instruments used for covariance measurements.(4) Statistical errors associated with single point measurements over a finite averaging time, and with lateral separation of two sensor arrays being compared.

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In the fall of 1968 an International Intercomparison Experiment was conducted to compare, among other things, acoustic anemometers designed for measurements of atmospheric turbulence. Excellent agreement was obtained in measurements of the vertical component, but an important discrepancy was revealed in measurements of the downwind velocity. The discrepancy proved far more significant in the cospectra than in the spectra themselves. It is evident that great care must be taken in the design of such instruments. An acoustic instrument was shown to have insufficient signal-to-noise ratio to serve as a thermometer under the near-neutral conditions often encountered over water.Comparison of the data-handling and data-analysis techniques showed that although the methods differed widely, the results were essentially identical.

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