Studies on object reconstruction from space using three-line scanner imagery

The paper investigates the capability of object reconstruction from space for two specific projects. Both of them are based on the use of three-line scanner systems allowing for simultaneous digital image recording from three different angles. An efficient model for combined point determination is proposed, considering the digital image data as well as orbit information, GPS and INS observations. The resulting accuracy is estimated from project oriented simulations. Finally, the possibilities for DTM generation, orthophoto production and stereo compilation from three-line scanner imagery are discussed.     

The Application of Telemetry to Large-Scale Horizontal Anisotropic Permeability Determinations by Surface Tiltmeter Survey

An advanced two-way radio link (transceiver units) and data logging system have provided a powerful means of real-time series data collection and analysis. The application of this telemetry system to surface tiltmeter surveys provides significant cost savings for testing and analysis of deep, large-scale horizontal anisotropic permeability and heterogeneity determinations.
The determination of horizontal anisotropic properties requires one pumping well and eight to 10 tiltmeter monitoring stations. The validity of the depth of the test may reach 4,000 feet below land surface. With the addition of one partially penetrating observation well, the entire three-dimensional anisotropic permeability can be determined. With the addition of a fully penetrating well, the storage coefficient can be determined as well as leakage property (including vertical permeability of the confining layers). An example test case was analyzed for horizontal anisotropic permeability with remarkable success despite relatively unfavorable detection conditions.
A thorough understanding of the geology overlying the aquifer system must be made in order to assess the applicability of the surface tiltmeter survey to large-scale horizontal anisotropic permeability determinations.     

Petrographische und Kalium-Argon-Untersuchungen an basischen tertiären Vulkaniten zwischen Westerwald und Vogelsberg

Between the upper tertiary volcanic areas of Westerwald and Vogelsberg (central Western Germany) occur more than 40 isolated tertiary volcanic dikes, eroded necks, plugs and domes. Twelve of these volcanic rocks have been investigated petrographically and chemically and classified by means of their modal and chemical composition. Additional modal analyses have been performed on seven other volcanics. On seventeen volcanic occurences K-Ar-whole rock age determinations have been made. The K-Ar age determinations yield- with the exception of an olivine-nephelinite — values between 27 and 15 Ma. Regarding the known intervals of volcanic activities of the Westerwald- and Voge1sberg-areas, most of the examined volcanics can be related genetically with one of the adjacent volcanic areas. There seems to be no geographical overlapping of volcanics showing Westerwaldages and Vogelsberg-ages. A possible influence of excess-Ar-bearing phases (e. g. mantle xenoliths) and an Ar-loss of constituent matter of the groundmass have been estimated by additional age determinations of enriched samples. These influences — partially compensating each other — may shift the K-Ar whole rock age to a maximum of 5 % and thus do not exceed the dimension of the standard deviations. A distinct NNE-SSW-striking fault in the region between Marburg and Gießen is situated parallel with the eastern border of the “Rheinisches Schiefergebirge”. Volcanics showing Westerwald-age and Vogelsberg-age respectively reach this fault, but obviously do not overlap it. Relations between rock-type an rock age, as it has been observed for the volcanics of the northern Hessian Depression (Kreuzer et al. 1973;Wedepohl 1982) cannot be proved certainly. On the other hand, similar to the basaltic rocks of the northern Hessian Depression, the youngest volcanic product is an olivine-nephelinite (9 Ma).     

A new calcium-aluminate from a refractory inclusion in the Leoville carbonaceous chondrite

The first meteoritic occurrence of CaAl₄O₇ is described from a Ca-Al-rich inclusion (CAI) in the Leoville carbonaceous chondrite. This CAI consists mainly of gehlenitic melilite, spinel, perovskite, and hibonite. CaAl₄O₇ is a minor component and occurs within melilite preferentially in portions rich in perovskite.The CAI is enveloped by a succession of three rims (from inside out): (a) hibonite+melilite+spinel+perovskite, (b) diopside, and (c) olivine.On the basis of mineral associations found and from the presence of moderately volatile elements (Fe and Cr) we conclude that the CaAl₄O₇-bearing CAI from Leoville is of residual nature. CaAl₄O₇ is apparently stable in the very Mg- and Si-poor environment of this CAI and is probably of igneous origin.The rims are interpreted as products of partial evaporation (rim (a)) and associated re-condensation (rims (b) and (c)).     

Rock Magnetic Investigation of Historical Lavas Used in Palaeointensity Studies

Five samples from historical lava flows on Mt. Etna, which had previously been used in a palaeointensity study, were examined using a combination of rock magnetic and microscopic techniques to elucidate the causes of failure of palaeointensity determination. The samples were characterised using a combination of low-temperature susceptibility (LT-), Bitter pattern imaging and scanning electron microscope (SEM). High-temperature susceptibility curves and hysteresis loops had been previously measured by Calvo et al. (2001). Of the five samples only one gave an accurate palaeointensity. This sample was deuterically oxidised and consisted of large exsolved ore grains. It was only possible to distinguish this sample either optically or magnetically from a similar sample by the LT- warming curves; the unsuccessful sample displayed alteration in the LT- warming curves, which was not readily observed in the high temperature susceptibility curves. It is proposed that the measurement of LT- curves before and after heating could be a more sensitive method of determining suitability for palaeointensity determination than previous rock magnetic pre-selection techniques.