Tourism Statistics and the Business Register in Italy： A Comparative Analysis and future Outlooks for Integration

After the proposal of a possible insertion of tourism statistics （supply side） （TS） into Framework Regulation Integrating Business Statistics （FR1BS） on which an interesting debate is in progress between Eurostat and NSls, Istat （Italian Institute of Statistics） has started a costs/benefits analysis of this integration. ASIA （Statistical Register of Active Enterprises）, built up by Istat, represents in Italy the official source about the structure and the economic performance of the enterprises. ASIA, whose statistical units are enterprises of industry and services, has been developed through the statistical integration of different administrative sources, other minor archives available （covering particular sectors） and structural business statistics currently produced by Istat. The supply side TS are produced by lstat through surveys via Intermediate Bodies （Local Authorities）： each Intermediate Body has its own local register of accommodation establishments based on Local Kind-of-activity unit （LKAU）. In this paper, the results of a comparative analysis between the statistical units as recorded in ASIA and as surveyed by TS are presented; from first outcomes, considerable issues about data quality appear both at level of coverage for the three Nace groups of the TS （also underlined in the Methodological Manual on Tourism Statistics where for Italy a difference of 70% is reported） and for loss information relating to the location of the activities （switching from LKAU to Enterprises） as well as for timeliness （ASIA has two years of delay）. Then, the administrative local tourism registers （LTR） are analysed to understand： how many they are, their dissemination in the Italian territories, their primary purpose and source, the variables contained, the frequency of updates. This preliminary analysis is needed to identify the operative activities that Istat, together with the Intermediate Bodies, should start to use administrative archives for statistical purposes and to develop a unique tourism satellite archive （TSA）, facing many difficulties related to the reception of several LTR as well as methodological issues for record linkage. On the other hand, a TSA would lead numerous advantages： a unique and official list of internal accommodation establishments; a step towards integration of TS into FRIBS; a starting point to begin to use also administrative data produced by the Italian Police （mandatory communications on guests in the interests of public safety）, having a comparison term to assess their coverage.

STATISTIC PROPERTIES OF NOISE FIELD OF MOVING SOURCE IN SHALLOW WATER AND ITS EFFECTS ON SIGNAL PROCESSING FOR THE NOISE RANGING SONAR

In this paper the properties of space- time correlation function of the noise field of moving source in layered statistic inhomogeneous medium are studied and the effects of random fluctuating boundary are considered as well.It has been shown, theoretically and experimentally, multi-path propergating effects cause the dispersion of the correlation function and fluctuations of the medium refraction index and the boundary cause the fluctuation of it.The effect of the movement of the noise source on the output of real- time correlator is equivalent to a low- pass filter added the drift of space- time correlation function.These properties of the correlation function cause grave degradation of the signal processing gain of noise ranging sonar system.The fluctuating and the distortion of conrrelation function made it difficult to realize the noise ranging.So in this paper, a method of space correlation ranging by a linear array of four points with short separation and long span and a technigue of dual- correlation signal processing are presented. By this, the influences of previously mentioned factors are greatly overcomed.Futhermore, for the long period and great delay fluctuation of the dual- correlation function output caused by internal wave, a method of limited memory Quasi- Kalman filtering is developed and the effective accurate ranging and tracing of noise ranging sonar are able to be tralized finally.