GNSS AND PHOTOGRAMMETRY BY THE SAME TOOL: A FIRST EVALUATION OF THE LEICA GS18I RECEIVER

Leica Geosystems recently introduced a multi-constellation GNSS sensor named GS18i. It is capable to perform tilt compensation and has an integrated photogrammetric camera, allowing the users to measure inaccessible features: this is called visual positioning. The Laboratory of Geomatics, at the University of Pavia – Italy, performed a first evaluation of the rover. Five accessible points were measured repeatedly with the pole having different tilt angles; measurements’ total number was 2077. After moderate blunder detection, RMSE values are 12, 10 and 18 mm, for the East, North and height components.Measurement quality is substantially independent from the pole’s tilt angle. Moreover, ten points belonging to a building’s façade were repeatedly measured by photogrammetry, through the integrated camera, from distances in the range between 4 and 12 meters. In total, 1436 measurements were acquired. After blunder detection, RMSE values are 45, 25 and 66 mm, for the x, y and z components of a local cartesian system. Measurement quality mildly depend on the object-camera distance. Despite a good overall accuracy, results show some surprising aspects: the high ratio between the planimetric component x and y, the counterintuitive behaviour of the y dispersion, which decreases when the distance increases. While the present paper aims at simply being a first evaluation of the rover, next activities will deal with rigorous and controlled photogrammetric processing of the images and will also include simulations, in order to ascertain the role played by the various error sources involved.

Analitical definition of the law of change in the traction resistance of the plowshare and justification of its model

An analytical definition of the law of change in the traction resistance of the plowshare is proposed, and its mathematical model is justified. To confirm these theoretical studies, experiments were conducted in the soil channel of the North-Caucasus Research Institute of Horticulture and Viticulture. According to a specially developed program, solutions in numerical form were carried out on a PC. To solve this problem, we used the Fourier, Sturm-Liouville equations, transformed from the polar system to the Cartesian system. The results obtained for the first eight harmonics were processed by the spline-approximation program, and then a regression analysis was performed. The pair correlation coefficient was calculated. Based on the obtained values, a graph of the dependence of the soil layer’s movement in the transverse plane on the forward movement was constructed.

Introduction

Starting in the 1660s, a number of philosophers argued for occasionalism, a doctrine that was first developed in medieval Islamic thought. The seventeenth-century thinkers who revived occasionalism—including Arnold Geulincx, Louis de la Forge, Gerauld de Cordemoy, and, most famously, Nicolas Malebranche—were deeply influenced by the philosophy of Descartes. This book will consider the relationship between Cartesianism and occasionalism, and examine the arguments that led Descartes’ followers to endorse occasionalism. It argues that the Cartesian occasionalists chose to adopt occasionalism as a way to defend and develop the Cartesian system—and that these theoretical motivations are crucial to understanding the force of their arguments for occasionalism. In order to understand the goals or motives of a historical figure such as Descartes or Malebranche, we can compare that figure to his or her historical counterparts. This Introduction explains the concept of a counterpart, following David Lewis.

The Eigenproblem Translated for Alignment of Molecules

Molecular conformation as a subproblem of the geometrical shaping of the molecules is essential for the expression of biological activity. It is well known that from the series of all possible sugars, those that are most naturally occurring and usable by living organisms as a source of energy—because they can be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway—are D-sugars (from the Latin dextro). Furthermore, the most naturally occurring amino acids in living cells are L-sugars (from the Latin laevo). However, a problem arises in dealing with the comparison of their conformers. One alternative way to compare sugars is via their molecular alignment. Here, a solution to the eigenproblem of molecular alignment is communicated. The Cartesian system is rotated, and eventually translated and reflected until the molecule arrives in a position characterized by the highest absolute values of the eigenvalues observed on the Cartesian coordinates. The rotation alone can provide eight alternate positions relative to the reflexes of each coordinate.

Some studies on Lorentz transformation matrix in non-cartesian co-ordinate system

The Lorentz matrices for transformation of co-ordinates in Cartesian system are presented for the cases when the relative velocity between two reference frames is along X , Y and Z axes. The general form of the matrix for transformation of co-ordinates from unprimed to primed frame has been deduced in case of Cartesian co-ordinate system with the help of the above matrices. This matrix has not been transformed to the cases of cylindrical and spherical polar co-ordinates due to the fact that the calculations are cumbersome and lengthy. Hence, considering the relative velocity between two frames along a co-ordinate axis the transformation matrix has been found out for cylindrical and spherical co-ordinates.

What is Cartesianism?

Although Bernard le Bovier de Fontenelle has often been treated as merely a “popularizer” of Descartes’s philosophy, it is shown here that Fontenelle’s Cartesianism is a peculiar one. Cartesianism is mainly treated by Fontenelle as an exemplary modern “way of reasoning”, and absolutely not as a coherent “system” that one should adhere to. This has two consequences: first, this way of reasoning, the “geometrical spirit”, can be applied to domains that the Cartesian system would have forbidden (poetic, politics, etc.); and second, this way of reasoning, supposedly relying on higher norms of clarity, is used by Fontenelle to oppose the Newtonian system of attraction at a time when all his contemporaries are adopting it.

Remaining gaps in open source software for Big Spatial Data

The volume and coverage of spatial data has increased dramatically in recent years, with Earth observation programmes producing dozens of GB of data on a daily basis. The term Big Spatial Data is now applied to data sets that impose real challenges to researchers and practitioners alike. As rule, these data are provided in highly irregular geodesic grids, defined along equal intervals of latitude and longitude, a vastly inefficient and burdensome topology. Compounding the problem, users of such data end up taking geodesic coordinates in these grids as a Cartesian system, implicitly applying Marinus of Tyre's projection. A first approach towards the compactness of global geo-spatial data is to work in a Cartesian system produced by an equal-area projection. There are a good number to choose from, but those supported by common GIS software invariably relate to the sinusoidal or pseudo-cylindrical families, that impose important distortions of shape and distance. The land masses of Antarctica, Alaska, Canada, Greenland and Russia are particularly distorted with such projections. A more effective approach is to store and work with data in modern cartographic projections, in particular those defined with the Platonic and Archimedean solids. In spite of various attempts at open source software supporting these projections, in practice they remain today largely out of reach to GIS practitioners. This communication reviews persisting difficulties in working with global big spatial data, current strategies to address such difficulties, the compromises they impose and the remaining gaps in open source software.

Remaining gaps in open source software for Big Spatial Data

The volume and coverage of spatial data has increased dramatically in recent years, with Earth observation programmes producing dozens of GB of data on a daily basis. The term Big Spatial Data is now applied to data sets that impose real challenges to researchers and practitioners alike. As rule, these data are provided in highly irregular geodesic grids, defined along equal intervals of latitude and longitude, a vastly inefficient and burdensome topology. Compounding the problem, users of such data end up taking geodesic coordinates in these grids as a Cartesian system, implicitly applying Marinus of Tyre's projection. A first approach towards the compactness of global geo-spatial data is to work in a Cartesian system produced by an equal-area projection. There are a good number to choose from, but those supported by common GIS software invariably relate to the sinusoidal or pseudo-cylindrical families, that impose important distortions of shape and distance. The land masses of Antarctica, Alaska, Canada, Greenland and Russia are particularly distorted with such projections. A more effective approach is to store and work with data in modern cartographic projections, in particular those defined with the Platonic and Archimedean solids. In spite of various attempts at open source software supporting these projections, in practice they remain today largely out of reach to GIS practitioners. This communication reviews persisting difficulties in working with global big spatial data, current strategies to address such difficulties, the compromises they impose and the remaining gaps in open source software.

Remaining gaps in open source software for Big Spatial Data

The volume and coverage of spatial data has increased dramatically in recent years, with Earth observation programmes producing dozens of GB of data on a daily basis. The term Big Spatial Data is now applied to data sets that impose real challenges to researchers and practitioners alike. The difficulties are partly related to a lack of tools supporting appropriate Coordinate Reference Systems (CRS). As rule, these data are provided in highly irregular geodesic grids, defined along equal intervals of latitude and longitude. Compounding the problem, users of such data end up taking geodesic coordinates in these grids as a Cartesian system, implicitly applying Marinus of Tyre's projection. A first approach towards the compactness of global geo-spatial data is to work in a Cartesian system produced by an equal-area projection. There are a good number to choose from, but those commonly supported by GIS software invariably relate to the sinusoidal or pseudo-cylindrical families, that impose important distortions of shape and distance. The land masses of Antarctica, Alaska, Canada, Greenland and Russia are particularly distorted with such projections. A more effective approach is to store and work with data in modern cartographic projections, in particular those defined with the Platonic and Archimedean solids. In spite of various attempts at open source software supporting these projections, in practice they remain today largely out of reach to GIS practitioners. This communication reviews persisting difficulties in working with worldwide big spatial data, current strategies to address such difficulties, the compromises they impose and the remaining gaps in open source software.