Solutions for Exterior Orientation in Photogrammetry: A Review

The determination of the attitude, the position and the intrinsic geometric characteristics of the camera is recognised as the fundamental photogrammetric problem. It can be summarised as the determination of camera interior and exterior orientation parameters, as well as the determination of 3D coordinates of object points. The term "exterior orientation"of an image refers to its position and orientation related to an exterior (object space) coordinate system. Several methods can be applied to determine the parameters of the orientation of one, two or more photos. The orientation can be processed in steps (as relative and absolute orientation) but simultaneous methods (such as bundle adjustments) are now available in many software packages. Several methods have also been developed for the orientation of single images. They are based in general on geometric and topological characteristics of imaged objects.
This paper presents a survey of classical and modern methods for the determination of the exterior parameters in photogrammetry, some of which are available as software packages (with practical examples) on the Internet. The methods presented are classified in three principal groups. In the first, a selection of approximate methods for applications that do not require great accuracy is presented. Such methods are also used to calculate values required for iterative processes. In the second group, standard point–based methods derived from collinearity, coplanarity or coangularity conditions are briefly reviewed, followed by line–based approaches. The third group represents orientation methods based on constraints and on concepts of projective geometry, which are becoming of increasing interest for photogrammetrists. In the last section, the paper gives a summary of existing strategies for automatic exterior orientation in aerial photogrammetry.     

Compartmentalisation of fluid migration pathways in the sub-Andean Zone, Bolivia

Numerous observations indicate that faults play a major role on the migration pathways of fluids in the Bolivian sub-Andean Zone. Most oil seeps in the foothills are located on faults, but oil fields in the foredeep are closed by faults. In the foothills, analysis of cements in fractures inside and around fault zones indicates that the faults act as barriers for transversal migration but can be preferential lateral migration pathways for both hydrocarbons and water. A detailed study of these apparent contradictions suggests that the hydraulic behaviour of faults changes with depth in relation with sandstone diagenesis, but it is strain-independent. From microstructural analyses of fault zones, we suggest that the main controlling factor is temperature, which facilitates or inhibits quartz precipitation. This result implies that the same fault is a barrier for lateral and transversal migration at depths >3 km, due to sealing of fractures by authigenic quartz at T>80 °C, and is a lateral drain in its shallower parts. As a result, the various thrust sheets are isolated from a hydraulic point of view, whereas migration in the foreland may take place over long distances (>100 km).     

Narrative warm/cold variations in continental western Europe, AD 708 -1426

An extended narrative dataset of the Medieval time AD 708-1426 in continental western Europe was set up. Some 30-year-moving mean seasonal temperature deviation series were reconstructed. A- warming trend occurred around AD 1200. During the warm stage, seasonal cycle might be weak due to frequent cool summers. Significant warm summer conditions did not occur until the late 14th century, when the annual temperature level began decreasing. The mean warm season temperature level during the late 14th to the early 15th century might be about 0.3°C higher than the present. It was suggested to cautiously comment on historical climates for different seasons.     

Automated trend reinforcement of aeromagnetic data

Aeromagnetic maps poorly represent lineaments that are at acute angles to the flight-line direction. Commonly used gridding algorithms cannot cope with local trends, magnetic anomalies at an angle with the main trend of the map, and tend to generate closed contours around the flight lines. By introducing some a priori information, it is possible to add extra data between the flight lines, i.e. trend lines, to reinforce local trends. The proposed automated technique is based on a nearest neighbour search of the maxima and minima in the aeromagnetic map. The resulting map is more realistic and derived maps, such as vertical gradients and analytical signal maps, are greatly improved. Moreover, this automated procedure is user independent and easy to implement. The technique is demonstrated on aeromagnetic data from the Kirkland Lake region, in north-eastern Ontario, Canada.     

Small valley bottom deposits in the sandy districts of the Sarthe basin (France): climatic and/or human origin?

The study of the small valley bottom deposits in a sandy district where several recent erosional events have occurred makes it possible to distinguish deposits, which are caused by climatic oscillations from those induced by both climate and human activities. The coarse alluvium with flints, which reached the main valleys prior to the Subboreal, was transported by greater flows than those which resulted from later human-induced flood discharges, where flints were not evacuated from the small valleys. Radiocarbon dates of peat set those deposits in the Iron Age, in the transition from Antiquity to the Medieval period, at the end of the “optimum climatique de l'an Mil” and during the Little Ice Age. At the present time, human-induced flood discharges reach again the main valleys.     

Non-ionic surfactants adsorption: structure and thermodynamicsAdsorption des tensioactifs non ioniques : structure et thermodynamique

Adsorption of non-ionic surfactants from aqueous solutions has been studied for years because of its industrial relevance. These surfactants, made of an aliphatic part attached to a hydrophilic and polar chain, play an important role in diverse applications. Modelling of the adsorption mechanisms of surfactants has traditionally been based on the interpretation of adsorption isotherms. However, this first level of investigation is not sufficient for a complete understanding. Direct inspection of the adsorbed layer of non-ionic surfactant molecules at the solid–liquid interface is needed. This is an active field of research for almost 15 years, even if the subject is not completely settled down. The aim of this paper is to present a short review of this topic. I will restrict this paper to the case of non-ionic adsorption onto hydrophilic or polar solid interfaces. In the first part, I comment some experimental studies of non-ionic adsorption layer, including fluorescence spectroscopy, neutron scattering and atomic force microscopy. In the second part, a theoretical discussion about thermodynamics of adsorption is presented. A model involving an aggregative adsorption process is proposed. This last part will permit to raise some interesting questions concerning the role of the so-called ‘normal interaction’ (surfactant/solid interaction) to select the optimal surface aggregate curvature. To cite this article: P.E. Levitz, C. R. Geoscience 334 (2002) 665–673.     

Origine et évolution du soufre au sein de l'aquifère des Sables infra-molassiques du Bassin aquitainOrigin and evolution of sulphur in the Infra-Molassic Sands Aquifer from the Aquitaine Basin

New data on isotopic composition of sulphur and oxygen in dissolved sulphates are used to determine the origin of sulphate ions (SO₄^2?) in the water of the Infra-Molassic Sands Eocene aquifer. Two very distinct origins appear: one is the gypsum dissolution, from the molasse, and the second is the pyrite oxidation, present at the bottom of and within the aquifer. These isotopic analyses helped, in agreement with hydrogeology, to identify geochemical basins whose properties modify the chemical water composition. They also highlight the existence of bioreduction areas. To cite this article: L. André et al., C. R. Geoscience 334 (2002) 749–756.     

Kriging and Semivariogram Deconvolution in the Presence of Irregular Geographical Units

This paper presents a methodology to conduct geostatistical variography and interpolation on areal data measured over geographical units (or blocks) with different sizes and shapes, while accounting for heterogeneous weight or kernel functions within those units. The deconvolution method is iterative and seeks the point-support model that minimizes the difference between the theoretically regularized semivariogram model and the model fitted to areal data. This model is then used in area-to-point (ATP) kriging to map the spatial distribution of the attribute of interest within each geographical unit. The coherence constraint ensures that the weighted average of kriged estimates equals the areal datum.This approach is illustrated using health data (cancer rates aggregated at the county level) and population density surface as a kernel function. Simulations are conducted over two regions with contrasting county geographies: the state of Indiana and four states in the Western United States. In both regions, the deconvolution approach yields a point support semivariogram model that is reasonably close to the semivariogram of simulated point values. The use of this model in ATP kriging yields a more accurate prediction than a naïve point kriging of areal data that simply collapses each county into its geographic centroid. ATP kriging reduces the smoothing effect and is robust with respect to small differences in the point support semivariogram model. Important features of the point-support semivariogram, such as the nugget effect, can never be fully validated from areal data. The user may want to narrow down the set of solutions based on his knowledge of the phenomenon (e.g., set the nugget effect to zero). The approach presented avoids the visual bias associated with the interpretation of choropleth maps and should facilitate the analysis of relationships between variables measured over different spatial supports.     

Global acceleration of lake sediment accumulation rates associated with recent human population growth and land-use changes

Journal of Paleolimnology - Sediment Accumulation Rate (SAR; measured as mm yr?1) and Mass Accumulation Rate (MAR; measured as g cm?2 yr?1) data were collected from...     

Slope‐to‐basin stratigraphic evolution of the northwestern Great Bahama Bank (Bahamas) during the Neogene to Quaternary: interactions between downslope and bottom currents deposits

Multichannel high‐resolution seismic data along the northwestern margin of the Great Bahama Bank (GBB), Bahamas, detail the internal geometry and depositional history of a Neogene‐Quaternary carbonate slope‐to‐basin area. The stratigraphic architecture through this period evolves from (i) a mud‐dominated slope apron during the Miocene, (ii) a debris‐dominated base‐of‐slope apron during the Late Pliocene and then (iii) return to a slope apron with very short prograding clinoformal aprons during the Pleistocene. This geometric evolution was broadly constrained by the development of the Santaren Drift by bottom current since the Langhian. The drift expands along the northwestern GBB slope, forming a continuous correlative massive feature that shows successive phases of growth and retreat and influenced the downslope sediments distribution. Indeed, Late Pliocene deposits are confined into the moat, forming a strike‐continuous coarse debrites belt along the mid‐slope, preventing their free expansion into the basin. The occurrence of basinal drift that operated since 15 Ma showed a significant upslope growth around 3.6 Ma and is interpreted as resulting from the closure of the Central American Seaway which also coincides with a global oceanographic re‐organization and climate changes in the Northern Hemisphere.