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31.
Riassunto Il presente lavoro si prefigge lo scopo di esporre il problema del sistema di riferimento per le misure di gravità relativa e di mostrare che il valore base «convenzionale» di Potsdam (981.274), considerato fino a pochi anni addietro come uno dei risultati di maggiore precisione, si presenta invece affetto molto probabilmente da un notevole errore. Ciò viene dimostrato principalmente dalla nuova misura assoluta al Nat. Bureau of Standards di Washington, e sembra essere confermato anche dalla misura assoluta di Leaingrado, di cui non ci sono ancora noti i risultati definitive. — Si propone perciò l'adozione di un nuovo sistema di riferimento «internazionale», basato cioè non più sul risultato di una sola misura assoluta della gravità, ma sulle più importanti finora eseguite. Le differenze relative fra di esse risultano da una nuova compensazione della rete internazionale delle stazioni di riferimento eseguita dall'A. — Saremo molto grati a tutti quei Geodeti che vorranno cortesemente iniziare la discussione su questo problema.
Summary It is shown that the «conventional» base-value of gravity at Potsdam (981, 274), considered until few years ago as one of the more precisious results, is instead affected very probably by a big error. This is demonstred first by the new absolute measure at Washington, and seems to be confirmed by the absolute measure at Leningrad too, for which definitive results are not yet known. — A new «international» reference system is therefore proposed, based no more on only one absolute measure of gravity, but on the most important ones until now executed. The relative differences between them result from a new compensation of the international net of the reference-stations excuted from the Author. — We shall be very thankfull to all those Geodesists who will kindly begun the discussion on this problem for its definitive solution.

Zusammenfassung Es wird gezeigt, dass der grundlegende konventionelle Referenzwert für relative Schweremessungen (Potsdam –981,274), der bis vor einigen Jahren als einer der genauesten Resultate bezeichnet wurde, von einem bemerkenden Fehler wahrscheinlich behaftet wird. Das wird vor allem durch die neue absolute Schweremessung von Washington gezeigt und scheint auch durch die absolute Schweremessung von Leningrad bestätigt zu werden, von der uns noch die endgültigen Resultaten fehlen. — Es wird daher die Verwendung eines neuen «internationalen» Referenz-Systems vorgeschlagen, das sich nicht mehr allein auf einer einzigen absoluten Schweremessung stützt, sondern auf den Wichtigsten die bisher ausgeführt wurden Die relativen Unterschiede entstammen aus einer neuen Ausgleichung des internationalen Netzes alle Hauptstationen, die von dem Verfasser ausgeführt wurde. — Wir werden alle Geodäten bedanken, welche die Diskussion dieser Frage freundlich beginnen möchten zur Erlangung seiner endgültigen Lösung.

Resumé Ce travail a le but d'exposer le plus clairement possible le problème du système de référence pour les mesures de gravité rélative et de montrer que la valeur fondamentale «conventionnelle» de Potsdam (981,274), considerée il y a quelques années comme un des résultats de la plus grande précision, se présent au contraire frappée très probablement d'une faute considérable. Tout cela est démontré surtout par la nouvelle mesure absolue faite à Washington et il semble être confirmé même par la mesure absolue de Leningrad, dont nous ne connaissons pas encore les résultats définitifs. — C'est pour cela que nous proposons l'adoption d'un nouveau système de référence international, qui soit fondé non plus sur le résultat d'une seule mesure absolue de la gravité, mais sur les plus importantes effectuées jusqu'ici. Les différences rélatives entr'elles resultent d'une nouvelle compensation du reseau international des stations de référence executée par l'Auteur. — Nous serons bien grès à tous ces Géodésiens qui voudront bien commencer la discussion sur ce problème, pur sa résolution définitive.
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Riassunto Con i procedimenti del Malkin, verificati sperimentalmente dal Ramsayer, viene intrapreso lo studio dell'influsso sulla declinazione in quota di alcune anomalie magnetiche in Italia, per cui esistono rilievi di dettaglio nella componente verticale (Colli Euganei, Stromboli). Per le zone anomale, capaci di influenzare il mantenimento della rotta nella navigazione aerea con la bussola, vengono proposte carte speciali con l'andamento delle isogone a varie quote fondamentali, di cui si presenta un saggio per l'isola di Stromboli. Attraverso un esame delle anomalie magnetiche in Italia, si indicano le zone di probabile e quelle di sicuro pericolo per la navigazione aerea con la bussola finchè non si potrà costruire per esse carte del tipo proposto. Per il rimanente spazio aereo italiano si prospetta l'opportunità che le isogone per i piloti siano costruite sulla base del campo normale.
Summary Applying the proceedings of Malkin verified by experiments of Ramsayer is studied the influence on the declination in upper levels of some magnetic anomalies in Italy, for which exist detailed reliefs in the vertical component (Colli Euganei, Stromboli). For the anomalous zones capable to influence the maintaining of the route in compass-airnavigation special maps are proposed containing the position of the isogons at various fondamental heights, an instance of which is presented for the isle of Stromboli. An examination of the magnetic anomalies in Italy shows the zones of probable and those of secure danger for compass-airnavigation as long as it will not be possible to prepare maps in the proposed type. For the rest of the Italian air-space the opportunity is prospected to construct the isogons for the pilots on the basis of the normal field.

Zusammenfassung Nach dem Malkinschen Verfahren wird der Einfluss einiger magnetischer Störgebiete (Colli Euganei, Stromboli) auf die Flugnavigation berechnet. Es wird vorgeschlagen, wo nötig, spezielle Deklinationskarten mit den Isogonen zu verschiedenen Haupthöhen vorzubereiten; ein Beispiel hiefür wird für die Insel Stromboli gegeben. Die Störgebiete, welche eine Gefahr für die Flugnavigation mit dem Magnetkompass bilden können, werden für Italien begrenzt. In dem übrigen Raum in Italien wird als das beste Verfahren für die Flugnavigation vorgeschlagen, die Isogonen nach dem vom Verf. berechneten Normalfeld darzustellen.
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A fast and efficient subsurface radar imaging procedure, based on a multi-channel cart system, has been developed and tested within the framework of a large-scale archaeological investigation project in northern Italy.The tested cart comprises 14 closely-spaced dipoles, rotated by 45° with respect to the dragging direction, and allows unidirectional scanning operations. Using this approach, an area of approximately 75 000m2 was surveyed daytime via recording of a dense grid of about 490km of radar profiles. Geo-referencing of the scanning trajectories was achieved operating a separate on-board differential Global Positioning System in real-time kinematic mode. In this configuration the final positioning error of the radar sweeps was less than 0.05m.The large amount of collected data, of the order of tens of GBytes, was processed, using an open-source software package, on a workstation-based environment. A set of specific codes was developed to fully automate the data processing and the image generation procedure. Critical steps during code development were the integration of positioning and radar data, the referencing of the single radar sweeps and the correction for changes in the spectral amplitude of the different channels.The processed data volume displays high signal coherency and reveals several well-defined reflectors, clearly visible both on vertical profiles and horizontal time slices. The plan of the Roman settlement could be revealed in detail proving the potential of the tested approach for assisting high-resolution archaeological investigations of large areas.  相似文献   
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The 1976 Friuli seismic sequence is known for itscomplexity, with several unusually large aftershocksoccurring in the epicentral area. The source region, where the northeastern part of the Alpine chain meetsthe northern Dinaric chain, is characterized by a complexcompressional tectonic regime. Previous studies have not clearly identified which of the two main tectonic systems was activated, in part due to the limited precision of derived earthquake parameters, such as hypocentral coordinates and focal mechanisms. We review the locations for the 10 largest events of the sequence, including theSeptember 16, 1977 and April 18, 1979 earthquakes andwe compute their centroid moment tensors. Source parameters are calculated using intermediate period surfacewaves and the modification of the Harvard centroid-moment tensoralgorithm proposed by Arvidsson and Ekström (1998). A summary of all available geological, geodetic and seismological data show that most of the earthquakes may be associated with the Periadriatic overthrust and other related thrust faults. Based on their locations and focal mechanisms only two ofthe early aftershocks (May 7, 1976 and May 9, 1976) appear instead to have occurred on Dinaric structures.  相似文献   
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Riassunto Si riferisce sul contributo portato dall'Istituto Geografico Militare alla conoscenza del campo magnetico terrestre in Italia ed altre regioni (Libia, Albania, Etiopia). Si forniscono particolari sulle carte magnetiche d'Italia e sulle carte delle isogone per la Libia, Albania, Dalmazia, Mediterraneo, Austria, Svizzera costruite dall'I.G.M. Per lo studio della geologia profonda in Italia sono state preparate anche le carte delle anomalie magnetiche (declinazione e componente orizzontale) e gravimetriche (secondo Faye e secondo Bouguer).
Zusammenfassung Der Verfasser behandelt den Beitrag des ital. Geogr. Mil. Instituts zur Erkenntniss des erdmagnetischen Feldes in Italien und anderen Gegenden. Einzelheiten werden über die magnetischen Karten von Italien gegeben und die Deklinationskarten für Libien, Albanien, Dalmatien, Mittelmeer, Schweiz und Ostmark, usw. erwähnt. Für Italien sind auch die Karten der magnetischen (D und H) und gravimetrischen (Faye und Bouguer) Isanomalen konstruiert worden.


Dott.Carlo Morelli, Capo della Sezione Geomagnetica dell'Istituto Geografico Militare.  相似文献   
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