Artificial Horizon Research Articles

Seasickness and partial peripheral vision obstruction with versus without an artificial horizon

Motion sickness (MS) is common when subjects are exposed to unfamiliar motion and affect individuals during travel. This study examines the immediate effect of two visual devices, in the form of glasses, on MS symptoms and associated physiological effects. The hypothesis is that peripheral vision obstruction reduces MS and that an additional beneficial effect could be observed when it is combined with an artificial horizon. Fifteen subjects with moderate to severe susceptibility to MS were exposed to a boat simulator in three conditions. Symptoms were assessed immediately after exposure. Time spent in the simulator, heart rate, and temperature were also recorded. The intensity of symptoms at the end of the experience did not differ, but time spent in the simulator before the onset of symptoms was significantly longer with peripheral vision obstruction (+36 %) and with both techniques combined (+40 %) than in the control condition. No difference was observed between the combined condition and peripheral vision obstruction alone. The glasses device used in this study (with or without an artificial horizon) delays the onset of symptoms. Further research is needed to confirm the mechanism that explains the benefits and to evaluate these effects during prolonged exposure to MS-inducing stimuli or after a period of familiarization with the device.

Reflection and Transmission of Airy Pulse from Controllable Periodic Temporal Boundary

AbstractThe interaction between two Airy pulses propagating at different wavelengths is numerically investigated. The periodically varying peak intensity of the soliton that emerges from stronger Airy pulse (pump pulse) leads to the formation of periodic temporal boundary. The relatively weaker Airy pulse (probe pulse) on interaction with this boundary gets partially reflected as well as transmitted. As a result, the probe pulse spectrum splits into two parts‐ the reflected pulse spectrum undergoes redshift while transmitted pulse exhibits blueshift. The probe pulse witnesses maximum reflection when point of interaction lies on the intensity maxima of the emergent soliton from pump Airy pulse. On the other hand, maximum transmission occurs when probe Airy pulse interacts at the intensity minima of the soliton. The reflection and transmission processes can be manipulated by tuning the time delay between pump and probe Airy pulses. In the case of a sufficiently intense pump pulse, the temporal boundary mimics the artificial optical event horizon, and the weak probe Airy pulse is completely reflected. This phenomenon is equivalent to the temporal version of total internal reflection. The results of the study hold potential applications in optical manipulation and temporal waveguiding.

Synthetic Displays and Their Potential for Driver Assistance Systems

Advanced visual display technologies typically supplement the out-of-window view with separate displays (e.g., analog speedometer or artificial horizon) or with overlays (e.g., projected speedometer or map). Studies on head-up displays suggest that altering the out-of-window view itself is superior to supplemental displays, as sensor-based information not normally visible to the driver can be included. Such novel synthetic displays have been researched for cockpit implementation but less so for driving. We discuss such view-altering synthetic displays in general, and camera–monitor systems (CMS) designed to replace rear-view mirrors as a special instance of a novel synthetic display in the automotive domain. In a standard CMS, a camera feed is presented on a monitor, but could also be integrated into the windshield of the car. More importantly, the camera feed can undergo alterations, augmentations, or condensations before being displayed. The implications of these technologies are discussed, along with findings from an experiment examining the impact of information reduction on a time-to-contact (TTC) estimation task. In this experiment, observers judged the TTC of approaching cars based on the synthetic display of a futuristic CMS. Promisingly, TTC estimations were unaffected by information reduction. The study also emphasizes the significance of the visual reference frame.

Analysis of errors of the artificial horizon sensor based on vision system

The article discusses the features of the practical implementation of the artificial horizon sensor based on the onboard vision system. Proposed, developed on the basis of well-known applications, a variant of the algorithm for the operation of an unmanned aerial vehicle orientation video system. The problems of automatic detection and determination of the position of the horizon line on changing digital images that make up the video stream from the onboard digital camera are shown. The analysis of the factors influencing the accuracy of estimation of carrier orientation angles using the proposed system is carried out. The results of a practical study are presented, characterizing the degree of influence of the considered factors on the total error. A discrete stochastic mathematical model of an unmanned aerial vehicle orientation system based on an onboard vision system has been developed. The possibility of providing an acceptable level of accuracy of the orientation video system due to certain technical and algorithmic solutions is shown. The conclusion is made about the expediency of using this system in autonomous multisensor navigation systems for unmanned aerial vehicles.

Artificial Horizon. Blind Flight in the History of Virtual Reality

Histories of virtual reality (VR) usually place its origins in computing. But this can be pushed back even further by considering early experiments in flight, principally in the endeavour to fly by instrument, that took place in the late 1920s and throughout the 1930s. This essay positions blind flight in the history of virtual reality and other immersive media in order to understand what sensory deprivation has to do with proprioception. Deprived of visual and aural senses, pilots were taught to reorient their perception of space using the artificial horizon as their guide. This essay uses the metaphor of the artificial horizon to discuss the relationship between sensory deprivation and sensory overload, both of which disturb the internal process that makes proprioception possible. Applying the method of media archeology places this study among others that have sought to historicise contemporary immersive media in unique ways, often with unexpected outcomes.&nbsp

Artificial event horizons in Weyl semimetal heterostructures and their non-equilibrium signatures

We investigate transport in type-I/type-II Weyl semimetal heterostructures that realize effective black- or white-hole event horizons. We provide an exact solution to the scattering problem at normal incidence and low energies, both for a sharp and a slowly-varying Weyl cone tilt profile. In the latter case, we find two channels with transmission amplitudes analog to those of Hawking radiation. Whereas the Hawking-like signatures of these two channels cancel in equilibrium, we demonstrate that one can favor the contribution of either channel using a non-equilibrium state, either by irradiating the type-II region or by coupling it to a magnetic lead. This in turn gives rise to a peak in the two-terminal differential conductance which can serve as an experimental indicator of the artificial event horizon.

Golden Hat of Schifferstadt

Four conical golden hats of the Late Bronze Age were discovered in southern Germany and western France in the nineteenth and twentieth centuries. Their users were probably members of a caste of priests or priestesses performing ceremonies linked to astronomical/calendrical knowledge. Another find discovered in central Germany, the Nebra bronze-gold disk, predates the golden hats by two to six centuries and has also been interpreted as an astronomical/calendrical ceremonial tool. From the burial location of the Nebra disk the Sun sets on the highest mountain of the Harz range, the Brocken, on the summer solstice. Here we investigate whether the burial location of the Schifferstadt golden hat also had an astronomical meaning. Our results make it possible to hypothesise that the Schifferstadt location was a natural astronomical/calendrical viewing place with the same function as several prehistoric circular enclosures, but where the natural hilly horizon of the Odenwald and the Palatinate Forest replaced the artificial horizon of the enclosures.

The geoecological analysis performed for the geochemical composition of ash and slag waste obtained at Zmiiv thermal power plant


 
 
 The objective of the study was the composition of ash and slag waste from the Zmiiv TPP (thermal power plant) and the peculiarities of migration of heavy metals (HM) from the place of storage of ash and slag waste into the ecosystem. To achieve this goal, the following tasks were solved: chemical analysis of ash and slag waste of the Zmiiv TPP; identification of the probability of HM migration into the soil environment in the places of ash and slag waste storage. Ash and slag of the Zmiiv TPP contain Cu, Cr, As, Cd, Ni, Pb in quantities several times higher than the threshold limit value (TLV). For ash and slag wastes, the total pollution rate was Zc = 43, which corresponds to a high level. That is, this artificial horizon is dangerous. HMs migrate to groundwater and soils near the ash stockpiles as a result of infiltration of precipitation waters, leaks from water-bearing communications, water filtration through the base of the ash stockpiles of the Zmiiv TPP. To determine soil contamination near the ash stockpiles, we analyzed soil at the distances of 0, 5, 10, 50 and 100 meters. The contents of the HM decreased further away from the stockpiles. At the distance of up to 100 meters from the dump, there were excesses of the threshold limit values for Ni, Cu, As, Cr in the soil. The concentration factor exceeded one for Cr, As, Cu, Cd, Ni. Only at the distance of 100 meters did the contents of Pb and Zn reached the background values. The calculation of the total rate of soil contamination allowed us to classify these soils as moderately dangerous and acceptable. However, the Zn indicator has several significant disadvantages, particularly it does not take into account the differences in the potential hazards of the elements, as well as, most importantly, the synergistic effects of polymetallic pollution. The coefficient of synergistic effect of heavy metals was 26.64 (in the soil of the ash stockpiles), then decreased, but even at the distance of 100 meters it equaled 11.23, i.e. at the distance of 0... 100 m from the ash stockpiles, the overall actions exceed the norm. The study revealed that Cu, Ni, Zn and Cr had low mobility in the soil near the ash stockpiles and therefore accumulated near the stockpiles, which may be explained by neutral and slightly alkaline soil pH values. The ratio of mineral phases and glass varied, but we should note the predominance of aluminosilicates, calcium silicates and glass in the ash and slag wastes. Heavy metal compounds are confined mainly to amorphized clay aggregates and soot-coal ash formation, to a lesser extent to slag glass and even less to grains of quartz sand. Since ash contains such fractions that can be easily carried by the wind, it should be assumed that ingress of HM into the ecosystem occurs by air, which also contributes to air pollution. The solution to the problem of ash and slag waste disposal can be found in their utilization in the production of construction materials, in road construction, but it is necessary to study the composition of ash and slag and the probability of migration of HM depending on the conditions of use.
 
 

Method for determining the transmission of a garret window from a direct sun component

Based on the experimental studies using the method of physical modeling under an artificial horizon NIISPh Moscow and the method of mathematical planning of the experiment, an analytical dependence of the light transmission coefficient on the direct component of sunlight, which characterizes the relationship between the height of the sun, geometric and lighting parameters of point skylights, was obtained.

Leans Illusion in Hexapod Simulator Facilitates Erroneous Responses to Artificial Horizon in Airline Pilots.

ObjectiveWe tested whether a procedure in a hexapod simulator can cause incorrect assumptions of the bank angle (i.e., the “leans”) in airline pilots as well as incorrect interpretations of the attitude indicator (AI).BackgroundThe effect of the leans on interpretation errors has previously been demonstrated in nonpilots. In-flight, incorrect assumptions can arise due to misleading roll cues (spatial disorientation).MethodPilots (n = 18) performed 36 runs, in which they were asked to roll to wings level using only the AI. They received roll cues before the AI was shown, which matched with the AI bank angle direction in most runs, but which were toward the opposite direction in a leans-opposite condition (four runs). In a baseline condition (four runs), they received no roll cues. To test whether pilots responded to the AI, the AI sometimes showed wings level following roll cues in a leans-level condition (four runs).ResultsOverall, pilots made significantly more errors in the leans-opposite (19.4%) compared to the baseline (6.9%) or leans-level condition (0.0%). There was a pronounced learning effect in the leans-opposite condition, as 38.9% of pilots made an error in the first exposure to this condition. Experience (i.e., flight hours) had no significant effects.ConclusionThe leans procedure was effective in inducing AI misinterpretations and control input errors in pilots.ApplicationThe procedure can be used in spatial disorientation demonstrations. The results underline the importance of unambiguous displays that should be able to quickly correct incorrect assumptions due to spatial disorientation.

Classical and quantal aspects of Minkowski's four-momentum in analog gravity

The electrodynamic theory of continuous media is probably the most convenient platform when trying to construct analog gravity theories. Quite naturally, this topic has gained considerable interest. One peculiar but not so very known feature in this context is the unconventional behavior of radiation energy and momentum in cases where superluminal fluid velocities are encountered, what, as known, is a major ingredient in analog gravity theories. These peculiar features are intimately connected with the spacelike character of Minkowski's four-momentum in electrodynamics. Here, we first consider an artificial model in which a Kerr-induced superluminal region is created in the right-hand region ($z>0$) in a left-moving, originally subluminal, fluid. We analyze the behavior of energy density, Poynting vector, and momentum density, and calculate the force on the artificial black hole horizon. Also, we delve into quantal aspects, looking for eventual production of particles associated with the sudden creation of the horizon, finding, however, that no particles are predicted to occur. The present paper continues a previous investigation by the author on the same topic, in Phys. Rev. A {\bf 100}, 032109 (2019). The subject as such is closely related to the famous Abraham-Minkowski problem.

Astronomical Observations of the 1869 Powell Expedition Through the Grand Canyon

During his 1869 expedition down the Green River and through the Grand Canyon, Major John Powell made astronomical observations using a sextant and artificial horizon to fix the locations of key points along the rivers that were only poorly known at the time. Latitude was obtained from the altitude of Polaris or meridian transits of stars or Saturn. Local mean time was determined from equal altitude observations of the Sun. The swamping of one of the expedition's small boats ruined the chronometers, meaning that they could not be used to keep Greenwich mean time and hence find longitude. As a substitute a series of lunar distance observations were undertaken. In this paper observations recorded in Powell's journal are reduced and analysed.

Brightness of the Night Sky Affects Loggerhead (Caretta caretta) Sea Turtle Hatchling Misorientation but Not Nest Site Selection

Sea turtles in the Gulf of Mexico, which are listed as either threatened or endangered under the US Endangered Species Act, face numerous threats but are particularly susceptible to the negative effects of light pollution on nesting beaches. Light pollution affects the distribution, density, and placement of nests on beaches, and disrupts seafinding in hatchlings emerging from nests; often leading to their death. Rapid urban growth near Gulf Islands National Seashore (GUIS), Florida, USA, over the last century has contributed to increased light pollution on its beaches. There is concern that light pollution is causing females to lay nests in at-risk locations subject to erosion and flooding, and is causing the observed high rates of hatchling misorientation. From 2015-2016, we measured brightness of the night sky, horizon profile, and lunar variables at GUIS at loggerhead (Caretta caretta) nests to assess the effects of brightness on laying of at-risk nests and hatchling misorientation. In addition, we quantified the effects of relocating at-risk nests on nest success. We found that contrast in brightness between the landward and seaward directions at GUIS was partially responsible for high rates of hatchling misorientation, and there was a strong moderating influence of lunar fraction and lunar altitude on hatchling misorientation: larger lunar fractions and lower lunar altitudes reduced misorientation. We did not document an effect of artificial light, horizon profile, or lunar fraction on the propensity of loggerheads to lay nests in at-risk locations, and found no evidence that relocating nests at GUIS reduced loggerhead nest success. Rather, we found nest success was improved and hatchling misorientation rates were reduced for relocated loggerhead nests.

Robust Object Tracking with Continuous Data Association based on Artificial Potential Moving Horizon Estimation

Abstract In this paper, a novel object tracking method based on moving horizon estimation (MHE) is introduced that integrates data association into numerical optimization on Bayesian state estimation. Object tracking is a classical problem that often appears in radar and vision systems for which either deterministic or probabilistic approach has been applied. While the former often encounter a failure of association, the latter avoids it by computing the expectation concerning the observations, but it requires the prior knowledge of the probabilistic distribution and may suffer from outliers. In this paper, a partially deterministic approach is built on MHE to resolve these concerns. Data association is realized by a potential function comprising the superposition of Gaussian distributions centered at each observed feature. The potential function is embedded into the stage cost of MHE; the optimal data association is conducted using the sequence of observations within the horizon. Thus robust object tracking is achieved utilizing multi-sampling data and integration of both dynamics and explicit constraints reflecting physical limitations. The advantage of the proposed method is verified through object tracking experiments on the crowded environment, where occlusion and misrecognition frequently occur.

Aviation Human Factors Related Industry News

Aviation Human Factors Related Industry News

Attitude Indicator Design in Primary Flight Display: Revisiting an Old Issue With Current Technology

ABSTRACTObjective: The experiments investigated the “old issue” of the attitude indicator’s moving-horizon versus moving-aircraft format with current primary flight display technology. Of interest was whether the effects found in earlier studies, favoring the moving-aircraft format, could be replicated with most recent technology including extended horizon displays, which depict the artificial horizon extended over the whole screen with overlaying speed and altitude scales (e.g., B787).Background: Although the moving-horizon format represents the standard approach in Western aviation, human factors research from the 1950s to the 1970s with round electromechanical instruments favored the moving-aircraft format with respect to better support of flight-path tracking and unusual attitude recoveries. However, recent studies using laboratory displays more similar to modern primary flight displays provided inconsistent results. This led to the assumption that the display’s design is a moderating factor of those effects.Method: Thirty-two novices and 13 pilots flew several tracking and recovery tasks in a PC-based simulator equipped with moving-horizon and moving-aircraft formats in classic and extended horizon design.Results: The data show that the previous effects favoring a moving-aircraft format of displaying bank information can be replicated with current primary flight display designs. However, the extended horizon design seems to reduce this effect, at least for pilots.Conclusion: The results suggest reconsidering the format of the attitude indicator at least for new applications, such as control of remotely piloted aircraft.

Evaluation of Two Approaches to Defining Extinction Risk under the U.S. Endangered Species Act.

The predominant definition of extinction risk in conservation biology involves evaluating the cumulative distribution function (CDF) of extinction time at a particular point (the "time horizon"). Using the principles of decision theory, this article develops an alternative definition of extinction risk as the expected loss (EL) to society resulting from eventual extinction of a species. Distinct roles are identified for time preference and risk aversion. Ranges of tentative values for the parameters of the two approaches are proposed, and the performances of the two approaches are compared and contrasted for a small set of real-world species with published extinction time distributions and a large set of hypothetical extinction time distributions. Potential issues with each approach are evaluated, and the EL approach is recommended as the better of the two. The CDF approach suffers from the fact that extinctions that occur at any time before the specified time horizon are weighted equally, while extinctions that occur beyond the specified time horizon receive no weight at all. It also suffers from the fact that the time horizon does not correspond to any natural phenomenon, and so is impossible to specify nonarbitrarily; yet the results can depend critically on the specified value. In contrast, the EL approach has the advantage of weighting extinction time continuously, with no artificial time horizon, and the parameters of the approach (the rates of time preference and risk aversion) do correspond to natural phenomena, and so can be specified nonarbitrarily.

Giving A Hand To Pilots With Animated Alarms Based On Mirror System Functioning

Controlled Flight Into Terrain (CFIT) accidents are among the most frequent and deadly accidents in aviation (IATA, 2016). Pilots have sometimes only a few seconds to react to the ‘Pull-Up’ alarm that indicates an imminent collision with the ground. The auditory modality of the alarm can generate stress, which can disrupt cognitive processes (Porcelli et al., 2008) and negatively impact the ability to take timely and appropriate actions (Scholz et al., 2009). While in general humans are less sensitive to auditory stimuli than to visual stimuli (Mrugalska et al. 2016), the auditory component of the ‘Pull-Up’ alarm is loud and prominent whereas its visual component is more discreet (i.e., small text). Consequently, a first step to enhance the efficiency of this alarm would be to increase the conspicuity of its visual component by enlarging the ‘Pull-Up’ text size and to increase its salience by displacing it from the artificial horizon to the bottom of the Primary Flight Display (PFD). However, enlarging the inscription may not be sufficient to cope with the loss of cognitive performance due to stress (BEA, 2009). Previous researched found that watching an action activates premotor cortex and pre-initiates the gesture imitation through the mirror neuron system (Ocampo & Kritikos, 2011). Therefore, presenting a video of the gesture to perform (i.e., a hand pulling the sidestick), in case of imminent impact with the ground, should pre-activate the motor reaction to the alarm and then improve the pilots’ performance in terms of reaction time. The present experiment aimed at assessing whether these ‘Pull-Up’ video better performance than more conventional ‘Pull-Up’ alarms. Both behavioral and electroencephalographic (EEG) results were used to assess the best alarm design.

Observing the green flash in the laboratory

The green flash is a well-known but elusive atmospheric phenomenon, in which the Sun is observed as it is setting behind a clear horizon. At the last moment before its disc disappears, a green flash is observed. The phenomenon is due to a vertical structure in the atmospheric refractive index which disperses the Sun’s light. We have simulated similar conditions in the laboratory, using a refractive index gradient in salt water in an aquarium. We photographed a white LED source simulating the Sun with an artificial horizon, and a blue flash was observed as the horizon obscured the image. Using the same system, we were also able to create a nonlinear refractive index profile and observe amplified mirage flashes, which are those normally observed in nature. We measured the refractive index gradient in the water with an Abbe refractometer.

Bull ants fine-tune ocelli to their lifestyle

Aeronautical engineers would love to know more about how flying insects control their manoeuvres. While human pilots are equipped with an artificial horizon for orientation, flying insects depend on three simple eyes (ocelli) set in the tops of their heads, which probably track the position of the horizon for stability. Intriguingly, some walking insects, such as members of the Myrmecia bull ant family, are also equipped with these unusual mini-eyes, even though they are probably of most use when members of a nest take to the wing to establish a new colony. Knowing that different members of the Myrmecia family, which often share the same territory, tend to be active at different times of day, Ajay Narendra wondered whether the insects have fine-tuned the specialised minute eyes to their different lifestyles.Armed with boots for protection from the ants’ fearsome stings, Narendra and Willi Ribi ventured out into the mountains and national parks in the vicinity of Canberra to collect workers of the walking day-active M. croslandi and dawn/day-active M. tarsata bull ants, while the dusk-active M. nigriceps and the nocturnal M. pyriformis ants had to be collected by infrared light at night, so that the pair could ‘spot them before they spotted us’. However, collecting flying members of each family was more challenging: ‘They fly out of the nest only once a year and were produced by only a few of the nests’, recalls Narendra, who eventually gathered night-flying M. nigriceps males and day-flying M. pyriformis males.Back in the lab, the pair took detailed images of the ants’ mini eye structures using light and electron microscopes. ‘The ocelli of the [walking] worker ants were surprisingly small compared to those of the flying ants’, says Narendra, who had to take great care handling the delicate structures. The day-active M. croslandi had the smallest ocelli lenses (76 μm), the species that were active in dim light and during the night had larger (129–201 μm) lenses, and the lenses of the flying ants were at least 10 times larger than those of the walking ants. The duo then compared the size of the light-sensitive portion of the eye, the rhabdom, across the four species of walking ants and found that the rhabdoms were widest in the ants that are active in dim-light conditions, probably to increase their light sensitivity, while the eyes of the flying ants were packed with 3 times as many rhabdoms as the eyes of the walking workers.Knowing that many insects are capable of sensing polarised skylight with their ocelli for navigation, Narendra and Ribi looked for structures in the ant ocelli that might detect light polarisation and were impressed to see that the two walking day-active species (M. croslandi and M. tarsata) had the structures, while the species that were active toward the dim end of the day lacked them. They also found that the ocelli of both species of flying ants were equipped with structures that may be sensitive to light polarisation, suggesting that the mini-eyes may be polarisation detectors, even though M. nigriceps flies at night.In addition, the two scientists was surprised when they discovered a reflective crystal structure in the ocelli of the flying night-active M. nigriceps males, toward the top of the rhabdom. Explaining that other animals use similar reflective eye coatings to enhance their sensitivity to light in dim conditions, Narendra suspects that the nocturnal fliers take advantage of the increased light sensitivity to make the most of what little light there is when they take to the wing.