Ground‐Penetrating Radar Velocity Determination and Precision Estimates Using Common‐Midpoint (CMP) Collection with Hand‐Picking,Semblance Analysis and Cross‐Correlation Analysis: A Case Study and Tutorial for Archaeologists

The most crucial parameter to be determined in an archaeological ground‐penetrating radar (GPR) survey is the velocity of the subsurface material. Precision velocity estimates comprise the basis for depth estimation, topographic correction and migration, and can therefore be the difference between spurious interpretations and/or efficient GPR‐guided excavation with sound archaeological interpretation of the GPR results. Here, we examine the options available for determining the GPR velocity and for assessing the precision of velocity estimates from GPR data, using data collected at a small‐scale iron‐working site in Rhode Island, United States. In the case study, the initial velocity analysis of common‐offset GPR profile data, using the popular method of hyperbola fitting, produced some unexpectedly high subsurface signal velocity estimates, while analysis of common midpoint (CMP) GPR data yielded a more reasonable subsurface signal velocity estimate. Several reflection analysis procedures for CMP data, including hand and automated signal picking using cross‐correlation and semblance analysis, are used and discussed here in terms of efficiency of processing and yielded results. The case study demonstrates that CMP data may offer more accurate and precise velocity estimates than hyperbola fitting under certain field conditions, and that semblance analysis, though faster than hand‐picking or cross‐correlation, offers less precision.     

Isolde Hausser (7. 12. 1889-5. 10. 1951), Technische Physikerin und Wissenschaftlerin am Kaiser-Wilhelm-/Max-Planck-Institut für Medizinische Forschung,Heidelberg

Historical sociobiographic accounts on members of the scientific and technical professions in the years of the Weimar Republic and after, are as yet scarce. This applies notably to women in the scientific community. Having formally been admitted to academic studies at German Universities only in 1908, their claims of wanting to apply their newly gained knowledge and to pursue academic careers were still not unquestioned by society. The social and cognitive integration of “the female” in male dominated science organisation, especially in the natural sciences and their kin fields in industry, remains problematic to-day. Isolde Hausser, daughter of the ambitious but little succesful inventor-entrepreneur Hermann Ganswindt, took her doctoral degree in physics at Berlin University in 1914, then worked as head of a group at a “Telefunken” laboratory for vacuum tubes till 1929, before she became research scientist at the Kaiser Wilhelm Institute for Medical Research, Heidelberg. There she worked on photoerythemaes and the formation of pigment and discovered the specific action of longwave ultraviolet. She contributed important results to our knowledge on the constitution and the behaviour of organic compounds by modern physical methods. She died of cancer on 5th October, 1951.     

The Measurement by Airborne Synthetic Aperture Radar (SAR) of Disturbance Within the Nasca World Heritage Site

In this paper we report on our use of Synthetic Aperture Radar (SAR) as a means of monitoring the Lines and Geoglyphs of Nasca and Pampas de Jumana World Heritage Site in Peru, where the colossal ground drawings, popularly known as the Nasca Lines, are found. Our research to date indicates that the environment in which the Nasca geoglyphs are found, and the nature of the geoglyphs themselves, are suited perfectly for investigation by SAR. SAR also provides a new and valuable tool for understanding the human activities and natural processes that have damaged the geoglyphs and which, unchecked, will continue to do so in the future. Further, SAR can be used to categorize geoglyphs according to structural differences and similarities in ways that have heretofore not been possible, thereby serving as a basis for a geoglyph catalogue.     

Integrating radar and laser-based remote sensing techniques for monitoring structural deformation of archaeological monuments

Ground-Based Synthetic Aperture Radar Interferometry (GBInSAR) and Terrestrial Laser Scanning (TLS) were purposely integrated to obtain 3D interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments. The paper describes the procedure to implement this integrated approach in the real-world situations of surveillance of archaeological and built heritage. Targeted tests were carried out on the case study of the Domus Tiberiana sited along the northern side of the Palatino Hill in the central archaeological area of Rome, Italy, and displacements of the monument were monitored over almost one year of acquisition. The GBInSAR – TLS integration provided updated information about the condition of the archaeological structures in relation to their history of instability mechanisms, and did not highlighted a general worsening for the stability of the entire monument. Point-wise and prompt detection of displacement anomalies and/or sudden changes in displacement trends proved the suitability of the method to support early warning procedures, also to evaluate effects on the masonry due to human activities.     

GPR and inductive electromagnetic surveys applied in three coastal sambaqui (shell mounds) archaeological sites in Santa Catarina state, South Brazil

In this article, GPR – Ground Penetrating Radar and inductive electromagnetic (EM38 equipment) results are presented for three archaeological sites of shell mounds located between Laguna and Jaguaruna cities, mid-southern coast of Santa Catarina state, Brazil. The Jabuticabeira II, Santa Marta IV, and Encantada III sites were studied. These sites consist of carbonate shell mounds built by societies that inhabited this region during the pre-colonial period (7.5–1.3 ky BP). Geophysical responses obtained in these archaeological sites had allowed the identification of anomalous regions related to archaeological point targets as well as continuous targets, correlated to the shell mound's structure and buried geologic features. GPR numerical modelling studies were done in order to evaluate the performance of the GPR method in relation to materials found in that environment, besides helping interpretations of real results. The synthetic GPR model was a good match with real data obtained in the field. So, the real and synthetic results serve as a reference guide to direct excavation activities in these archaeological and geological structures. In the Jabuticabeira II shell mound, lithic materials and burials were found amidst archaeological layers characterized by sediment rich in organic material, ferruginous concretions, and loose shells. In the Santa Marta IV archaeological site, a concentration of ceramic materials, burials and fireplaces were found. In the Encantada III site, a strong anomaly characterized by a hyperbolic reflection was related to the presence of a silicified tree root; a great example of ambiguity in shallow geophysics interpretation in archaeological applications. Results functioned as a guide to archaeological excavations, allowing cost and time reduction as well as contributing to improve the knowledge of these archaeological sites situated in southern Brazil.     

Nanozonation in Dense Cities: Testing a Combined Methodology in Barcelona City (Spain)

Microzonation is widely used in seismic risk evaluations to define the predominant period values, which are usually associated with extended areas of a few hundred meters. However, the representative values corresponding to these areas are obtained from few measurements in each area. Thereby, results are accurate only in the case of depth-dependent soils. However, not detected narrow and sharp lateral changes in soil are potentially the cause of imprecision and could be a source of specific errors. This article aims to present several tests conducted in order to emphasise the importance of accurate selection of points, to underscore the necessity of more precise and detailed evaluations, and to suggest a possible methodology to select the most appropriate data acquisition points. Results highlight the need to divide microzonation areas into smaller zones for a precise evaluation in locations where sudden changes in soil characteristics exist. Therefore, in such sites the requirement of nanozonation appears; defining zones with the same soil response. Distance between vibration measurements could be the main problem for nanozonation; data acquisition in areas with irregular geology can be time consuming when a precise analysis is required. In the most complicated environments or in dense cities, it could even be unfeasible. Consequently, it is necessary to establish a functional methodology to adequately distribute the measurement points throughout the area. On this occasion, three sites in Barcelona city were studied. This city is surrounded by mountains at NW, W, and S, and by the Mediterranean Sea at N and E. As a consequence, the shallow geology is characterized by many paleochannels and streams that are currently buried. These geological structures most likely affect the soil response. Several tests were carried out to determine this dependence. The tests were based on Ground Penetrating Radar (GPR) surveys to define the paleochannels position and on vibration measurements in order to define properly the soil response. The results from both methods were compared to the known geology to accurately define the effect of the shallow geological structures in the predominant period and in the GPR images. Areas with the same geological unit but different materials were identified in the GPR images, allowing the selection of the most appropriate distance between vibration measurements in each place. As a final result, predominant periods that were measured over the same geological unit but over different material showed changes higher than the 40% in short distances. This procedure could improve the soil response maps, including nanozonation.     

Biophysikalisches Doppelleben, 1939–1946. Oder: Räume der Lange‐weile. Zur (Nicht‐)Zäsur des ‘Informationsdiskurses’

Biophysical Double‐lives, 1939–1946. Or: Spaces of Boredom. On ‘Information Discourse’ and (Dis)continuities in the Life Sciences. Arguably, few things have shaped the historiography of the mid‐twentieth century psy‐sciences (and indeed, of the life sciences and science/technology/intellectual life quite generally) more profoundly than the story of cybernetics. This essay aims to undermine this technofuturistic picture of epistemological upheavals, of cyborg regimes of knowing, and of the incipient post‐human, by reinserting back into the story the rather dull and unspectacular lives (and occupations) of the great majority of British, ‘diverted’ biologists during World War II. Instead of Ratio Clubbers or Macy‐Conference frequenters, this essay is concerned with a much larger population of would‐be biologists and their most pedestrian appropriations of, and exposures to, electronics. What I argue is that the prevalence and systematicity of such exposures in the course of the personnel‐hungry radio‐war points to a very different – low‐key – picture of the war/technology‐induced deflections of biological science at mid‐century. As an example of how deeply at odds narrations of cybernetic's ascent tend to sit with developments on ground level, special attention will be devoted to the physiologists‐turned‐radar‐scientists Alan Hodgkin and Andrew Huxley, and their war‐time, or more properly, spare‐time investigations into the biophysics of nerve. The latter – technical, difficult, and utterly unphilosophical – while absent from the cyber‐theme‐focused historiography, provided the basis for the tremendous impact Hodkgin and Huxley would in fact have on the mainstream, disciplinarily conservative physiological sciences; the larger aim however is to weave these far from peculiar biographical trajectories into a somewhat bigger picture of the intersections between radar electronics and biological science: a picture which does not centre on sensational discourses but on mundane electronic practices; and thus, on the generational experience of those who were known at the time as “ex radar folk with biological leanings”.     

Ground penetrating radar survey of a prehistoric site in southern Italy

In this paper, we present and discuss the results of a ground penetrating radar (GPR) study carried out in an area of southern Italy where a karst cave with prehistoric remains was found. The aim of the study involved the imaging of the subsurface stratigraphy, both inside and outside the cave, in order to assist archaeologists in an excavation programme.The survey grid comprised 18 intersecting GPR profiles. Problems associated with the use of the GPR within a cave environment are highlighted and the data processing sequence designed to extract useful geo-archaeological signatures is described. Interpretation of the radar sections was controlled by the excavation of two trenches (inside and outside the cave), allowing detailed outlining the complex stratigraphy and the reconstruction of Palaeolithic and Neolithic subsurface horizons.