Ground Position Research Articles

PHOTOGRAMMETRIC ACCURACY AND MODELING OF ROLLING SHUTTER CAMERAS

Abstract. Global climate change is one of the major challenges that all nations are commonly facing. Long-term observations of the Antarctic ice sheet have been playing a critical role in quantitatively estimating and predicting effects resulting from the global changes. The film-based ARGON reconnaissance imagery provides a remarkable data source for studying the Antarctic ice-sheet in 1960s, thus greatly extending the time period of Antarctica surface observations. To deal with the low-quality images and the unavailability of camera poses, a systematic photogrammetric approach is proposed to reconstruct the interior and exterior orientation information for further glacial mapping applications, including ice flow velocity mapping and mass balance estimation. Some noteworthy details while performing geometric modelling using the ARGON images were introduced, including methods and results for handling specific effects of film deformation, damaged or missing fiducial marks and calibration report, automatic fiducial mark detection, control point selection through Antarctic shadow and ice surface terrain analysis, and others. Several sites in East Antarctica were tested. As an example, four images in the Byrd glacier region were used to assess the accuracy of the geometric modelling. A digital elevation model (DEM) and an orthophoto map of Byrd glacier were generated. The accuracy of the ground positions estimated by using independent check points is within one nominal pixel of 140 m of ARGON imagery. Furthermore, a number of significant features, such as ice flow velocity and regional change patterns, will be extracted and analysed.

PHOTOGRAMMETRIC ACCURACY AND MODELING OF ROLLING SHUTTER CAMERAS

Global climate change is one of the major challenges that all nations are commonly facing. Long-term observations of the Antarctic ice sheet have been playing a critical role in quantitatively estimating and predicting effects resulting from the global changes. The film-based ARGON reconnaissance imagery provides a remarkable data source for studying the Antarctic ice-sheet in 1960s, thus greatly extending the time period of Antarctica surface observations. To deal with the low-quality images and the unavailability of camera poses, a systematic photogrammetric approach is proposed to reconstruct the interior and exterior orientation information for further glacial mapping applications, including ice flow velocity mapping and mass balance estimation. Some noteworthy details while performing geometric modelling using the ARGON images were introduced, including methods and results for handling specific effects of film deformation, damaged or missing fiducial marks and calibration report, automatic fiducial mark detection, control point selection through Antarctic shadow and ice surface terrain analysis, and others. Several sites in East Antarctica were tested. As an example, four images in the Byrd glacier region were used to assess the accuracy of the geometric modelling. A digital elevation model (DEM) and an orthophoto map of Byrd glacier were generated. The accuracy of the ground positions estimated by using independent check points is within one nominal pixel of 140 m of ARGON imagery. Furthermore, a number of significant features, such as ice flow velocity and regional change patterns, will be extracted and analysed.

Response to Commentaries on "Misidentified Flying Objects?"

Article responding to commentaries on the paper, "Misidentified Flying Objects?" elaborating a middle ground position regarding the question of what is "really real."

Intravehicular, Short- and Long-Range Communication Information Fusion for Providing Safe Speed Warnings.

Inappropriate speed is a relevant concurrent factor in many traffic accidents. Moreover, in recent years, traffic accidents numbers in Spain have fallen sharply, but this reduction has not been so significant on single carriageway roads. These infrastructures have less equipment than high-capacity roads, therefore measures to reduce accidents on them should be implemented in vehicles. This article describes the development and analysis of the impact on the driver of a warning system for the safe speed on each road section in terms of geometry, the presence of traffic jams, weather conditions, type of vehicle and actual driving conditions. This system is based on an application for smartphones and includes knowledge of the vehicle position via Ground Positioning System (GPS), access to intravehicular information from onboard sensors through the Controller Area Network (CAN) bus, vehicle data entry by the driver, access to roadside information (short-range communications) and access to a centralized server with information about the road in the current and following sections of the route (long-range communications). Using this information, the system calculates the safe speed, recommends the appropriate speed in advance in the following sections and provides warnings to the driver. Finally, data are sent from vehicles to a server to generate new information to disseminate to other users or to supervise drivers’ behaviour. Tests in a driving simulator have been used to define the system warnings and Human Machine Interface (HMI) and final tests have been performed on real roads in order to analyze the effect of the system on driver behavior.

A Stochastic Analysis of the Transient Current Induced along the Thin Wire Scatterer Buried in a Lossy Medium

The paper deals with the stochastic collocation analysis of a time domain response of a straight thin wire scatterer buried in a lossy half-space. The wire is excited either by a plane wave transmitted through the air-ground interface or by an equivalent current source representing direct lightning strike pulse. Transient current induced at the center of the wire, governed by corresponding Pocklington integrodifferential equation, is determined analytically. This antenna configuration suffers from uncertainties in various parameters, such as ground properties, wire dimensions, and position. The statistical processing of the results yields additional information, thus enabling more accurate and efficient analysis of buried wire configurations.

Filtering algorithm and direction identification in relative position estimation based on induction loop-cable

A filtering algorithm and direction identification method are presented for the positioning system of the mid-speed maglev train. Considering the special structure of the mid-speed maglev train, the ground position estimation method is adopted for its traction system. As the train is running, the induction loop-cable receives the signal sent by the on-board antenna to detect the position and direction of the train. But the height of the on-board antenna relative to the loop-cable is highly vulnerable to the change of the suspension height and the magnetic field produced by the traction during traveling, which may lead to amplitude fluctuation of the received signal. Consequently, the position estimation may be inaccurate. Therefore, a discrete second-order nonlinear trackdifferentiator is proposed based on the boundary characteristic curves, and the new differentiator could also extract the running direction of the train for the traction system. The experimental results show that the tracking differentiator can effectively filter out the signal interference and can provide accurate direction signal.

ATrunk—An ALS-Based Trunk Detection Algorithm

This paper presents a rapid multi-return ALS-based (Airborne Laser Scanning) tree trunk detection approach. The multi-core Divide & Conquer algorithm uses a CBH (Crown Base Height) estimation and 3D-clustering approach to isolate points associated with single trunks. For each trunk, a principal-component-based linear model is fitted, while a deterministic modification of LO-RANSAC is used to identify an optimal model. The algorithm returns a vector-based model for each identified trunk while parameters like the ground position, zenith orientation, azimuth orientation and length of the trunk are provided. The algorithm performed well for a study area of 109 trees (about 2/3 Norway Spruce and 1/3 European Beech), with a point density of 7.6 points per m2, while a detection rate of about 75% and an overall accuracy of 84% were reached. Compared to crown-based tree detection methods, the aTrunk approach has the advantages of a high reliability (5% commission error) and its high tree positioning accuracy (0.59m average difference and 0.78m RMSE). The usage of overlapping segments with parametrizable size allows a seamless detection of the tree trunks.

An integrated optimisation approach to airport ground operations to foster sustainability in the aviation sector

With increasing air traffic, rising fuel costs and tighter environmental targets, efficient airport ground operations are one of the key aspects towards sustainable air transportation. This complex system includes elements such as ground movement, runway scheduling and ground services. Previously, these problems were treated in isolation since information, such as landing time, pushback time and aircraft ground position, are held by different stakeholders with sometimes conflicting interests and, normally, are not shared. However, as these problems are interconnected, solutions as a result of isolated optimisation may achieve the objective of one problem but fail in the objective of the other one, missing the global optimum eventually. Potentially more energy and economic costs are thus required. In order to apply a more systematic and holistic view, this paper introduces a multi-objective integrated optimisation problem incorporating the newly proposed Active Routing concept. Built with systematic perspectives, this new model combines several elements: scheduling and routing of aircraft, 4-Dimensional Trajectory (4DT) optimisation, runway scheduling and airport bus scheduling. A holistic economic optimisation framework is also included to support the decision maker to select the economically optimal solution from a Pareto front of technically optimal solutions. To solve this problem, a multi-objective genetic algorithm is adopted and tested on real data from an international hub airport. Preliminary results show that the proposed approach is able to provide a systematic framework so that airport efficiency, environmental assessment and economic analysis could all be explicitly optimised.

Does The Trunk Affect The Knee Abduction Moment During A Run To Cut Task?

When an athlete cuts to change direction, greater ipsilateral lean of the trunk and pelvis over the planted leg are thought to contribute to elevated knee abduction moments. Greater knee abduction moments are linked to the risk for Anterior Cruciate Ligament tears. However, there have been few investigations to date that have formally assessed the relationship of trunk and pelvis ipsilateral lean to the knee abduction moment during cutting. PURPOSE: The aim of this study was to assess the relationships between peak ipsilateral frontal plane trunk and pelvis angles to the knee abduction moment during a run to cut task. METHODS: As part of an ongoing study, a cutting task at a self selected speed was performed on ten healthy subjects (5 male, 5 female, age of 23 ± 2.8 years) who had no previous injuries. Participants performed a cutting task by planting on their right leg and cutting toward the left direction at 45 degrees. Kinematic variables of interest included peak frontal plane trunk angle, pelvis angle, and knee abduction moment. Means, standard deviation, and Pearson Correlation were calculated to determine the association between the variables. Due to the preliminary nature of the data, a one tailed test of significance was used. RESULTS: Mean values for trunk angle, pelvis angle, and knee abduction moment were 0.5 ± 4.9°, -8.0 ± 3.0°, -0.7 ± 0.3 Nm/kg, respectively. There was a moderate but not significant correlation between trunk angle and knee abduction moment (r= 0.465, p=0.088) and between pelvis angle and knee abduction moment (r=0.474, p=0.083). CONCLUSION: Greater trunk and pelvis angles were found to be moderately related to greater knee abduction moment during a run to cut task. Although the correlations were not statistically significant, with additional participants we expect the power will increase resulting in significant relationships. These relationships between trunk positioning and the knee abduction moment indicate that greater lateral trunk lean and pelvic tilt over the stance leg can increase frontal plane knee load and perhaps injury risk. However, these relationships were moderate suggesting other factors such as magnitude of the ground reaction force and position of the center of pressure may play a role in greater knee abduction moments as well.

Efficient Photocatalytic H2 Evolution: Controlled Dewetting-Dealloying to Fabricate Site-Selective High-Activity Nanoporous Au Particles on Highly Ordered TiO2 Nanotube Arrays.

Anodic self-organized TiO2 nanostumps are formed and exploited for self-ordering dewetting of Au-Ag sputtered films. This forms ordered particle configurations at the tube top (crown position) or bottom (ground position). By dealloying from a minimal amount of noble metal, porous Au nanoparticles are then formed, which, when in the crown position, allow for a drastically improved photocatalytic H2 production compared with nanoparticles produced by conventional dewetting processes.

Accurate direct georeferencing of aerial imagery in national coordinates

In aerial photogrammetry, data products are commonly needed in national coordinates, and, in practice, the georeferencing is often performed in the required national map projection frame directly. However, as a map projection frame is not Cartesian, some additional corrections are necessary in the georeferencing process to take account of various map projection distortions. This paper presents a new map projection correction method for the direct georeferencing of aerial images in national coordinates, which comprises of three consecutive steps: (1) a rough intersection to predict ground point coordinates in the Cartesian space; (2) calculating map projection corrections; and (3) a fine intersection. Benefiting from the explicit estimation of ground positions in the Cartesian space, our new method can directly adopt the accurate map projection distortion model that was previously developed for the direct georeferencing of airborne LiDAR data in national coordinates. Simulations show that the correction residuals of our new method are smaller by one order of magnitude than those of the previous best approach while their computational costs are at the same level, and even in an extreme scenario of 8000m flight height above ground, the maximum error of our method is only several centimeters, which can be safely neglected in practical applications.

The effect of output-input isolation on the scaling and energy consumption of all-spin logic devices

All-spin logic (ASL) is a novel approach for digital logic applications wherein spin is used as the state variable instead of charge. One of the challenges in realizing a practical ASL system is the need to ensure non-reciprocity, meaning the information flows from input to output, not vice versa. One approach described previously, is to introduce an asymmetric ground contact, and while this approach was shown to be effective, it remains unclear as to the optimal approach for achieving non-reciprocity in ASL. In this study, we quantitatively analyze techniques to achieve non-reciprocity in ASL devices, and we specifically compare the effect of using asymmetric ground position and dipole-coupled output/input isolation. For this analysis, we simulate the switching dynamics of multiple-stage logic devices with FePt and FePd perpendicular magnetic anisotropy materials using a combination of a matrix-based spin circuit model coupled to the Landau–Lifshitz–Gilbert equation. The dipole field is included in this model and can act as both a desirable means of coupling magnets and a source of noise. The dynamic energy consumption has been calculated for these schemes, as a function of input/output magnet separation, and the results show that using a scheme that electrically isolates logic stages produces superior non-reciprocity, thus allowing both improved scaling and reduced energy consumption.

Wuhan Ionospheric Oblique-Incidence Sounding System and Its New Application in Localization of Ionospheric Irregularities

In this paper, a novel oblique-incidence ionosonde (Wuhan Ionospheric Oblique-Incidence Sounding System) and its new application in the localization of the ionospheric irregularities are presented. Due to the usage of the binary-phase-coded waveform, a large signal processing gain, a high Doppler and range resolution, and a large unambiguous detection range can be achieved in this ionosonde. This ionosonde also adopts the peripheral component interconnect extensions for instruments (PXI) bus technology and is designed as a small-sized PXI-based system. Furthermore, a high-performance oven-controlled crystal oscillator that is disciplined by the Global Positioning System is used to achieve a good time and frequency synchronization. With multichannel digital receiver and multiple receiving sites, this ionosonde can be applied in the localization of the ionospheric irregularities. The details of the system configuration, the ambiguity function of the sounding waveforms, the signal processing algorithm, and the time and frequency synchronization method are described. The experimental results show that the virtual height along with the ground position of the ionospheric field-aligned irregularities can be preliminarily localized with this ionosonde.

Analysis of judo match for seniors

Background (Introduction): To bring training process closer to the competition conditions it is necessary to conduct judo fight analyzes at all competition levels. That is why the main objective of this work is to analyze the structure of judo fight on the Grand Prix level in the context of the new rules. Material and methods: The paper analyses technical solutions in 125 fights of men’s part of competition, and 68 fights of women’s competition. All analyzed fights were part of elimination rounds of Grand Prix Tournament Rijeka (2013). Results: Statistically significant number of fights ends in stand up position before the end of regular time in both, men and women, categories. Nage waza remain the most important techniques in judo fight and the most used techniques in ground position are hold down techniques. Nevertheless, one can find a great deal of specificities through each weight category. Conclusions: According to the results of performed analysis one can conclude that judo fight requires a high level of technical efficiency and the physical ability. The differences in the analyzed variables, which occur between weight categories in the men's and women's competition, require an individualized approach in training process.

New Pose Estimation Methodology for Target Tracking and Identification

Ground Moving Target Indicator (GMTI) and High Resolution Radar (HRR) can track position and velocity of ground moving target. Pose, angle between position and velocity, can be derived from kinematics estimates of position and velocity and it is often used to reduce the search space of a target identification (ID) and Automatic Target Recognition (ATR) algorithms. Due to low resolution in some radar systems, the GMTI estimated pose may exhibit large errors contributing to a faulty identification of potential targets. Our goal is to define new methodology to improve pose estimate. Besides applications in target tracking, there are numerous commercial applications in machine learning, augmented reality and body tracking.

Genotoxicity analysis of Fromilid and Methotrexate using Allium test

Ground Moving Target Indicator (GMTI) and High Resolution Radar (HRR) can track position and velocity of ground moving target. Pose, angle between position and velocity, can be derived from kinematics estimates of position and velocity and it is often used to reduce the search space of a target identification (ID) and Automatic Target Recognition (ATR) algorithms. Due to low resolution in some radar systems, the GMTI estimated pose may exhibit large errors contributing to a faulty identification of potential targets. Our goal is to define new methodology to improve pose estimate. Besides applications in target tracking, there are numerous commercial applications in machine learning, augmented reality and body tracking.

Vertical force calibration of smart force platform using artificial neural networks

INTRODUCTION: The human body may interact with the structures and these interactions are developed through the application of contact forces, for instance due to walking movement. A structure may undergo changes in the dynamic behaviour when subjected to loads and human bodies. The aim of this paper is to propose a methodology using Artificial Neural Networks (ANN) to calibrate a force platform in order to reduce uncertainties in the vertical Ground Reaction Force measurements and positioning of the applied force for the human gait. METHODS: Force platforms have been used to evaluate the pattern of applied human forces and to fit models for the interaction between pedestrians and structures. The designed force platform consists in two force plates placed side by side in the direction of walking. The reference voltages applied to the Wheatstone bridge were used for calibration as the input data to the ANN, while the output data were the estimated values of the standard weights applied to the force platform. RESULTS: It was presented a framework to enhance traditional calibration methods for force platforms (vertical component) using an ANN. The use of ANN shows significant improvements for the measured variables, leading to better results with lower uncertain values that are smaller than those using a simple traditional calibration. CONCLUSION: The results suggest that the calibration with the ANN method may be useful in obtaining more accurate vertical Ground Reaction Forces and positioning measurements in a force platform for human gait analysis.

Compact optical duplicate system for satellite-ground laser communications: application of averaging effects

In recent years, there has been considerable interest in satellite-ground laser communication due to an increase in the quantity of data exchanged between satellites and the ground. However, improving the quality of this data communication is necessary as laser communication is vulnerable to air fluctuation. We first verify the spatial and temporal averaging effects using light beam intensity images acquired from middle-range transmission experiments between two ground positions and the superposition of these images using simulations. Based on these results, we propose a compact and lightweight optical duplicate system as a multi-beam generation device with which it is easy to apply the spatial averaging effect. Although an optical duplicate system is already used for optical correlation operations, we present optimum design solutions, design a compact optical duplicate system for satellite-ground laser communications, and demonstrate the efficacy of this system using simulations.

Problems and Solutions in the Design of Rainwater Pipe Networks

At present, there is more storm waterlogging in our urban, one of the main reasons is that there are many disadvantages in rainwater pipe network design, this paper in the pipe network design must be reasonable to determine the ground water runoff coefficient, The ground water time, reduction coefficient, catchment area and position and quantity of gully according to the measured data, and appropriately increasing the recurrence interval according to the actual in engineering, hydraulic calculation as much as possible to select data sets larger diameter, accurate calculation time of flow, to reduce the urban storm waterlogging fundamentally.

Induced Voltage of Overhead Ground Wires in 50 0-kV Single-Circuit Transmission Lines

General grounding method of overhead ground wires adopted in Chinese 500-kV transmission lines is usually optical fiber composite ground wire (OPGW) grounded at each tower while common ground wire (CGW) insulated with one point grounded. Energy loss of OPGW and high induced voltage of CGW is a problem to be concerned as to its values and control methods. Both field measurement and ATP-EMTP simulation of induced current and induced voltage of overhead ground wires in a 500-kV single-circuit transmission line are carried out in this paper. Quantitative data of induced current and energy loss show the urgent necessity to reduce the energy loss and change the grounding method of overhead ground wires. A no-loss method for ground wires is proposed by comparing advantages and disadvantages of three grounding methods of overhead ground wires, where both OPGW and CGW are insulated with one point grounded. Induced voltage is calculated in different transposition pitch and segment length of ground wires with grounding position at the end of the line or at the midpoint of transposition pitch and segment. It shows that induced voltage of ground wires grounded at the midpoint of transposition pitch and segment is half of which grounded at the end. Moreover, induced voltage of overhead ground wires can be reduced to 500 V or other limited values by choosing a reasonable transposition pitch and grounding position.