In-flight Measurements Research Articles

Oral Health of Astronauts in Short- and Long-Term Missions in Space

INTRODUCTION: Space exploration presents unique challenges to human health due to space radiation, reduced gravity, and prolonged isolation. Astronauts should be prepared to manage medical and dental emergencies. This scoping review maps the evidence on oral health alterations and dental emergencies faced by astronauts during short- and long-term space missions. METHODS: A “Topical Team” assembled by the European Space Agency performed the review described herein. An electronic search was conducted on scientific databases, reference lists of relevant papers, specific textbooks, and space agencies’ databases. Inclusion criteria encompassed studies related to dental medicine in microgravity or outer orbital space conditions. Results are presented through narrative format. RESULTS: Out of 23,686 studies identified, 467 were considered eligible and 80 (54 reviews and 26 human-based studies) were included. The latter were classified into three broad topics: microbiology, space physiology and medicine, and space dentistry. Among the studies involving human subjects, 17 involved individuals who had spent time in space. There are only a few studies about oral health modifications and issues during spaceflight and those have limited evidence. Dental emergencies in space are relatively rare events that tend to increase with mission duration. DISCUSSION: The impact of microgravity on oral health requires further investigation. Preflight and in-flight measures should focus on prevention and treatment protocols for various dental issues to ensure crew safety and mission success. Understanding and addressing factors affecting oral health in microgravity will enhance the well-being of astronauts and the success of human exploration missions in space. Del Fabbro M, Khijmatgar S, Vandenberghe B, Kijak E, Kulesa-Mrowiecka M, Singhal I, Lorusso F, Xavier BB, Sampson V, Marfia G, Neefs D, Tartaglia GM. Oral health of astronauts in short- and long-term missions in space. Aerosp Med Hum Perform. 2025; 96(2):168–179.

Ground Calibration with Orthogonality Correction for Tri-Axis Fluxgate Magnetometer for CAS500-3

This paper presents ground calibration and orthogonality correction methods for the tri-axis fluxgate magnetometer (FGM), named as adaptive in-phase magnetometer (AIMAG), aboard the CAS500-3 satellite. The orthogonality errors of the FGM among the axes can lead to significant inaccuracies in magnetic field measurements. In this study, we employed Helmholtz coils and an autocollimator to apply controlled magnetic fields and adjust the magnetometer’s alignment. By deriving the correction matrix, we could transfer the sensor axes to the ideal orthogonal coordinate system. We validated the correction method by analyzing the sensor’s output under various magnetic field conditions. This correction method is expected to enhance the in-flight magnetic field measurements of the CAS500-3 satellite.

Determination of optimal solar-viewing geometry for in-flight polarization calibration using sun glint over ocean

The sun glint has been proven to be a valuable natural polarization calibration target because it is strongly polarized, and its polarization characteristics can be accurately simulated with models. It is convenient to calibrate the satellite’s in-flight polarimetry by comparing the polarization simulations with actual measurements. Meanwhile, the accuracy of polarization simulation at the top of the atmosphere (TOA) over sun glint is affected by several atmospheric and oceanic surface factors and depends on the specific solar-viewing geometry. In this paper, the sensitivity of the degree of linear polarization (DOLP) at the TOA to the uncertainties of the aerosol optical depth, aerosol model, absorption gas content (CWV, O3), sea surface instantaneous wind speed (WS), and chlorophyll concentration (Chl) under different solar-viewing geometries is analyzed via radiative transfer simulation. The error budgets indicate that aerosols and WS are the main error factors for polarization calibration, while the uncertainties of Chl and absorbing gases can be disregarded. The total DOLP error increases with the solar zenith angle and viewing zenith angle (i.e., the increase of atmospheric optical path) and the sun glint angle (SGA, the angle between the viewing and the specular directions of the sun) (i.e., the decrease of sun glint brightness). The dependence of the total DOLP error on SGA decreases with the WS (i.e., the increase of sun glint spot area and the decrease of the sun glint intensity) and increases with the wavelength (i.e., the decrease of atmospheric scattering contribution). Based on the error budgets, an optimized solar-viewing geometry screening strategy is proposed to ensure that the simulated DOLP error is limited to 0.02. The in-flight DOLP calibration result of POLDER/PARASOL shows that the proposed screening strategy obtained more calibration samples and covered a wider range of DOLP, especially for the samples with DOLP of less than 0.2, compared with the screening strategies of Toubbe et al. [IEEE Trans. Geosci. Remote Sens. 37, 513 (1999)IGRSD20196-289210.1109/36.739104]and Hagolle et al. [IEEE Trans. Geosci. Remote Sens. 42, 1472 (2004)IGRSD20196-289210.1109/TGRS.2004.826805] in previous work. The smaller standard error (SE) of the samples indicates more stable calibration results obtained for the optimized strategy. This research presents an optimized strategy for screening the solar-viewing geometry of the samples to calibrate satellite in-flight polarization measurements using the sun glint.

Measurement report: In-flight and ground-based measurements of nitrogen oxide emissions from latest-generation jet engines and 100 % sustainable aviation fuel

Abstract. Nitrogen oxides, emitted from air traffic, are of concern due to their impact on climate by changing atmospheric ozone and methane levels. Using the DLR research aircraft Falcon, total reactive nitrogen (NOy) in-flight measurements were carried out at high altitudes to characterize emissions in the fresh aircraft exhaust from the latest-generation Rolls-Royce Trent XWB-84 engine aboard the long-range Airbus A350-941 aircraft during the ECLIF3 (Emission and CLimate Impact of alternative Fuels 3) experiment. The impact of different engine thrust settings, monitored in terms of combustor inlet temperature, pressure and engine fuel flow, was tested for two different fuel types: Jet A-1 and, for the first time, a 100 % sustainable aviation fuel (SAF) under similar atmospheric conditions. In addition, a range of combustor temperatures and an additional blended SAF were tested during ground-based emission measurements. For the data measured during ECLIF3, we confirm that the NOx emission index increases with increasing combustion temperature, pressure and fuel flow. We find that as expected, the fuel type has no measurable effect on the NOx emission index. These measurements are used to compare to cruise NOx emission index estimates from three engine emission prediction methods. Our measurements thus help to understand the ground to cruise correlation of current engine emission prediction methods while serving as input for climate modelling and extending the extremely sparse data set on in-flight aircraft nitrogen oxide emissions to newer engine generations.

Senswing: A Force Sensing Wing for Intelligent Flapping-Wing Aerial Vehicles—Wing Design and Comprehensive Evaluation of Force Sensing Capabilities

This paper proposes a force-sensing wing, Senswing, to enhance the intelligence of flapping-wing aerial vehicles (FWAVs). Force perception is a crucial capability for robots to interact safely and effectively in unknown environments. However, FWAVs perform flapping motions with significant acceleration and deceleration, which can cause the flexure element inside force sensors to deteriorate due to repeated loading or even fail due to impulsive forces. To address this, we constructed a force measurement system by attaching 16 strain gauges directly to the wing root while maintaining high rigidity. We confirmed that the external force measurement capability closely matched the values obtained by a six-axis force sensor, with almost no error. Additionally, when measuring aerodynamic forces during wing flapping, the sensor could detect differences in wind speed even during flapping. With this sensor, FWAVs can achieve in-flight measurement of thrust and lift through a force-sensing system.

Advancements on the use of Filtered Rayleigh Scattering (FRS) with Machine learning methods for flow distortion in Aero-Engine intakes

In-flight measurements of aerodynamic quantities are a requirement to ensure the correct scaling of Reynolds and Mach number and for the airworthiness certification of an aircraft. The ability to obtain such measurement is subject to several challenges such as instrument installation, environment, type of measurand, and spatial and temporal resolution. Given expected, more frequent use of embedded propulsion systems in the near future, the measurement technology needs to adapt for the characterization of multi-type flow distortion in complex flow, to assess the operability of air-breathing propulsion systems. To meet this increasing demand for high-fidelity experimental data, the Filtered Rayleigh Scattering (FRS) method is identified as a promising technology, as it can provide measurements of pressure, temperature and 3D velocities simultaneously, across a full Aerodynamic Interface Plane (AIP). Τhis work demonstrates the application of a novel FRS instrument, to assess the flow distortion in an S-duct diffuser, in a ground testing facility. A comparison of FRS results with Stereo-Particle Image Velocimetry (S-PIV) measurements reveals good agreement of the out of plane velocities, within 3.3% at the AIP. Furthermore, the introduction of machine learning methods significantly accelerates the processing of the FRS data by up to 200 times, offering a substantial prospect towards real time data analysis. This study demonstrates the further development of the FRS technique, with the ultimate goal of inlet flow distortion measurements for in-flight environments.

Fault Detection on Short-Haul or Highly Dynamic Flights Using Transient Flight Segments

Abstract A machine learning-based approach is presented, which allows to detect persistent engine faults after a single flight. It utilizes transient in-flight measurements and a transient engine model. The time series of the residuals between the measured data and the data resulting from performance synthesis is evaluated using moving windows containing at least one transient segment. A continuous wavelet transformation and a pretrained convolutional neural network are utilized on the residuals for feature extraction. The fault detection is carried out via a one-class support vector machine, trained exclusively on nominal engine operation data. Therefore, the approach requires no a-priory knowledge of the effects of engine faults on the in-flight measurements. Under the assumption of persistent faults, all windows of a single flight, which contain at least one transient segment, are considered in order to improve the reliability of the fault detection. This approach is validated using measured data of a small helicopter engine that replicates the dynamic flight of the corresponding model helicopter on a ground test bed. Consequently, step changes as well as complex variations of the shaft power output are considered. Four standard gas path sensors are considered. The one-class support vector machine is used successfully to detect two types of total pressure sensor anomalies. Assuming a typical number of transient segments for an average short haul flight, it turns out that persistent faults can be detected within one flight with a probability of above 90%.

Reliability of Continuous Noninvasive Hemoglobin Monitoring in Healthy Participants During En Route Care Training.

Current standards for hemoglobin monitoring during air transports of U.S. combat wounded are invasive and intermittent. Fielded pulse co-oximeters can noninvasively measure total hemoglobin, but this parameter is not currently utilized. The primary objective of this study was to assess the percentage of vital sign measurements with successful capture of total noninvasive hemoglobin measurement using spectrophotometry-based technology for Hb (SpHb) measurements in healthy participants during training flights. Secondary objectives were to assess the feasibility of a novel electronic data capture mechanism from usual patient movement items and perform a pilot analysis of SpHb changes in healthy participants during transitions from ground to air transport. We conducted a feasibility study enrolling healthy participants who had hemodynamic monitoring during usual U.S. Air Force Critical Care Air Transport (CCAT) flight training exercises from 2022 to 2023. Usual CCAT monitoring equipment and currently used Masimo Rainbow® pulse co-oximeters had the capability to measure SpHb. After each training exercise, the study team wirelessly downloaded case files from patient monitors utilizing the Battlefield Assisted Trauma Distributed Observation Kit (BATDOKTM) Case Downloader application. We then calculated point and precision estimates for the percentage of time for successful SpHb capture during the exercise and compared this to pulse oximetry (SpO2) capture. An a priori precision analysis for percentage of flight-time with successful SpHb data capture and descriptive statistics were performed. This study received Exempt Determination by the 59th Medical Wing IRB. We analyzed 26 records with mean monitoring durations of 94.5 [59.3-119.9] minutes during ground phases and 78.0 [59.9-106.5] minutes during flight phases. SpHb measures were successfully captured for 97.7% (n = 4,620) of possible ground measurements and 97.2% (n = 3,973) of possible in-flight measurements compared to 99.5% ground and 98.2% in-flight capture for SpO2. Mean intervals of missing SpHb data were 2 ± 5 minutes on the ground and 4 ± 6 minutes in-flight. Mean SpHb increased by 0.93 ± 0.96 g/dL during the ground phase, but had minimal changes during ascent, cruising altitude or descent. The BATDOKTM Case downloader completed transfer for all files. Masimo Rainbow® SpHb pulse co-oximeters reliably captured continuous, noninvasive hemoglobin measurements using usual CCAT patient movement items in healthy participants during both ground and flight training. The BATDOKTM Case Downloader successfully imported case files from CCAT patient monitors. Mean SpHb measures had a small increase during the ground phase of monitoring followed by minimal changes when transitioning to flight altitude.

Analysis, optimization, and testing of a tilt-body aircraft

This paper proposes a new multidisciplinary design optimization framework for tilt-bodies to obtain the optimal combination of geometry and powertrain, achieving both long endurance and low transition power consumption at a 5 kg takeoff weight. A low-fidelity vortex lattice method is used to derive the aerodynamic coefficients. The tandem wings are trimmed using an optimization-based method, considering the effect of distributed propulsion on the trim solution through aero-propulsive interaction at low flight speed. Detailed powertrain parameters are fitted with fewer design variables to calculate power consumption. By analyzing the unique constraints of tilt-bodies, the optimization problem is established as a simultaneous analysis and design architecture, and solved with different numbers of rotors. The impact of the relative geometric relationship between the front and rear wings on aerodynamic performance and constraints is analyzed. Results demonstrate the full angle-of-attack flight capability of tilt-bodies. The optimal design can save nearly 1000 W in transition, with a pure cruise endurance of over 1 hour, which is competitive among other configurations. With an empty weight of only 2 kg, a portion of the battery can be allocated to a heavier payload. High-fidelity computational fluid dynamics corrects the errors of the vortex lattice method on non-lifting components, including the fuselage, nacelles, and landing gear. Finally, the feasibility of the optimal design and the accuracy of the framework are validated by wind tunnel tests and in-flight drag measurements on a test platform.

Flight Testing Of A Single Point Frequency Sweeping Filtered Rayleigh Scattering Probe

"We present a successful in-flight application of filtered Rayleigh scattering (FRS) for temperature measurement in close proximity to the air plane using a newly developed single point, frequency sweeping probe. The temperature measurement is of relevance in the quantification of the density required for the evaluation of velocity from Pitot-probe measurements to obtain the true air speed (TAS). Laser optical air data sensors have the potential for contactless measurements outside the aerodynamic boundary layer. They are capable of self-diagnosis of fault conditions (e.g. signal loss, increased measurement uncertainty or spectral distortion for FRS) thereby increasing the safety of the aircraft. Compared to classical probes, they are less susceptible potential icing and blockage issues. The FRS-results presented here, are the outcome of two separate flight campaigns, carried out in the Alpine region as well as in the North Sea area. Measurement data provided information on the functionality of the FRS-system under various flight and weather conditions. Furthermore, the implementation of the FRS measurement system in the aircraft is presented; application aspects and improvements are discussed. In particular, the measurement accuracy at the actually achievable measurement rate was analyzed. For straight ahead flights at constant height, temperature mean values were in good agreement with the flight data system of the DLR research aircraft Dassault Falcon 20 (D-CMET). Aiming at in-flight air data measurements, the optical FRS measurement system requires a real-time temperature sample rate of a few Hz. We demonstrate that 2 FRS spectra per second can be acquired by a newly developed method using frequency sweeps for temperature determination. The low signal intensity of cw-laser based FRS is countered using a combined transmitter/receiver optic that focusses the entire cw-laser power into one measuring point. The light backscattered from the probe volume is collected by the same optics, filtered and imaged in a confocal arrangement onto a photomultiplier. An improved and miniaturized version of the presented FRS system could be a part of a future optical air data system (OADS). However, the strength of FRS signal relative to bright ambient conditions (e.g. sunlight, cloud backscatter) must be further improved in order to be able to measure well above cloud cover. The potential for further development is foreseen even if the accuracy required for flight data systems (~0.5 K) has not yet been achieved at a temperature measurement rate of 2 Hz. "

Near- and Far-Field Acoustic Characteristics and Sound Source Localization Performance of Low-Noise Propellers with Gapped Gurney Flap

With the rapid industrialization utilizing multi-rotor drones in recent years, an increase in urban flights is expected in the near future. This may potentially result in noise pollution due to the operation of drones. This study investigates the near- and far-field acoustic characteristics of low-noise propellers inspired by Gurney flaps. In addition, we examine the impact of these low-noise propellers on the sound source localization performance of drones equipped with a microphone array, which are expected to be used for rescuing people in disasters. Results from in-flight noise measurements indicate significant noise reduction mainly in frequency bands above 1 kHz in both the near- and far-field. An improvement in the success rate of sound source localization with low-noise propellers was also observed. However, the influence of the position of the microphone array with respect to the propellers is more pronounced than that of propeller shape manipulation, suggesting the importance of considering the positional relationships. Computational fluid dynamics analysis of the flow field around the propellers suggests potential mechanisms for noise reduction in the developed low-noise propellers. The results obtained in this study hold potential for contributing to the development of integrated drones aimed at reducing noise and improving sound source localization performance.

A method of reconstruction of anisotropic fluxes of geomagnetically trapped particles from in-flight measurements of high precision

High anisotropy of geomagnetically trapped particles’ fluxes requires utilization of a complex methodology for their reconstruction from in-flight measurements. For precise position-sensitive instruments operating in the event-by-event mode, a standard approach is the one originally developed for the SAMPEX/MAST experiment. It consists in calculation of the instrument’s effective areas averaged over gyro-phase angle as a function of pitch angle of detected particles for detector’s different orientations relative to the geomagnetic field vector. This orientation normally changes as the instrument moves in space. Moreover, some space vehicles bearing a measuring instrument may and do change their orientation during flight by rotation of the instrument or as a whole. Each possible orientation needs an independent calculation of effective areas for each possible pitch angle, which is usually done by means of Monte-Carlo simulation. Therefore, especially for sophisticated devices, the calculation of an accurate and representative response function (consisting of a set of effective areas) may involve a vast amount of computation.In this paper, we propose a simplified approach, which is based on the assumption that for an anisotropic flux, the angular sphere the particles come to the detector from can be split into solid angle domains, within which the flux can be treated as isotropic. This allows one to use much easier computed geometrical factor or acceptance of the instrument as the proportionality factor. This method suggests that it can be calculated with respect to registration of the particles from these domains (we call it partial acceptance). The main advantage of the presented method is that the whole set of partial acceptances for each instrument orientation relative to the geomagnetic field vector and for all available values of (equatorial) pitch-angle for this orientation can be obtained from one simulation sample (for the given energy) of isotropic flux.

LTI/LQE: A Physics-Based Approach for Online Estimation of Dynamic Loads in the Rotating Frame

Accurate and online load monitoring of vital components located in the rotor system is important for not only inferring usage and estimating fatigue in those components but also for developing load alleviation/limiting control schemes. In the literature, on-board models for online (i.e., real-time) estimation of rotor component loads using available in-flight aircraft fixed-frame measurements are developed using neural networks, a statistical-based approach, or a combination of both. These models are aircraft-specific, do not capture the higher harmonic dynamics of the rotor system vibratory loads, and their synthesis requires obtaining a lot of data. To remedy these issues, this paper introduces a purely physics-based approach to online estimation of rotor system loads. The proposed approach can be applied to any rotary-wing vehicle, does not rely on a large amount of data, and captures the higher harmonic dynamics of the rotor system vibratory loads. The developed model entitled LTI/LQE is synthesized using a linear time invariant (LTI) model of helicopter-coupled body-rotor-inflow dynamics and a linear quadratic estimator (LQE), that is designed to correct the LTI model state response using fixed system measurements. The estimation fidelity of the LTI/LQE model is evaluated in simulation using a high-fidelity nonlinear model of a generic helicopter for online prediction of rotor blade pitch link loads arising from vehicle maneuvers. Results obtained using the LTI/LQE model revealed an interesting finding. It was found that the N/rev (where N is the number of blades) fixed system load measurements have information that can be leveraged to make an inference about the N/rev dynamic loads in the rotating system.

Calibration of MAJIS (Moons And Jupiter Imaging Spectrometer). III. Spectral calibration.

The Moons And Jupiter Imaging Spectrometer (MAJIS) is the visible and near-infrared imaging spectrometer onboard the European Space Agency (ESA)'s Jupiter Icy Moons Explorer mission. Before its integration into the spacecraft, the instrument undergoes an extensive ground calibration to establish its baseline performances. This process prepares the imaging spectrometer for flight operations by characterizing the behavior of the instrument under various operative conditions and uncovering instrumental distortions that may depend on instrumental commands. Two steps of the on-ground calibration campaigns were held at the instrument level to produce the data. Additional in-flight measurements have recently been obtained after launch during the Near-Earth Commissioning Phase. In this article, we present the analyses of these datasets, focusing on the characterization of the spectral performances. First, we describe and analyze the spectral calibration datasets obtained using both monochromatic sources and polychromatic sources coupled with solid and gas samples. Then, we derive the spectral sampling and the spectral response function over the entire field of view. These spectral characteristics are quantified for various operational parameters of MAJIS, such as temperature and spectral binning. The derived on-ground performances are then compared with in-flight measurements obtained after launch and presented in the framework of the MAJIS performance requirements.

Revival of the Aviation Industry in the Post-COVID Era - With Special Reference to Passengers Satisfaction in Domestic Airlines of India

India is the ninth-largest global aviation market, handling 121 million domestic passengers and its contribution to national GDP is 5%(2). The aviation sector has been disrupted by the COVID-19 pandemic but since mid-2022, it started reviving as the severity of the pandemic gradually slowed down. Investors, Airlines, Government, and Regulators are extra cautious about the safety protocols, regulations and passengers satisfaction in the post-COVID era. So far, no research has studied the passengers satisfaction level with all the new initiatives taken by Indian domestic airlines. Our empirical study addresses this gap by adopting a mixed method based on a survey of 224 passengers and a content analysis of 300 online reviews on domestic airlines. Important crucial inflight measures impacting passenger satisfaction are assessed through the qualitative study based on passengers feedback using Importance-performance analysis. The study has also validated the impact of most crucial inflight experiences on satisfaction through an SEM model. The findings have shown that airline passengers are largely satisfied with the Relationship quality with crew members and Safety and in-flight services but are not comfortable and secure with the in-flight ambient factors.

Numerical Analysis and Measurement Techniques for Aircraft Cabin Noise Using JAXA's Jet-FTB "HISHO"

The reduction of aircraft cabin noise is one of the important issues not only to increase passenger comfort but also to strengthen international competitiveness in aircraft development. JAXA has been conducting research activities on numerical and experimental prediction techniques of aircraft cabin noise. This paper focuses on the development of our cabin noise prediction tool using the Finite-Difference Time-Domain method, and in-flight noise measurement in the JAXA's Jet-Flying Test Bed (Jet-FTB) "HISHO" with the aim of grasping the cabin noise characteristics. The measurement data include the noise level near interior walls using the near-field acoustic holography method, the wall impedance, and structural vibrations, acquired through some flight test / ground test campaigns. The authors also explain validation results of our numerical prediction tool using microphone data measured in the Jet-FTB.

Aeromedical Transportation in an Area Intensive Care Unit: Experimental Study of Aircraft Pilots Undergoing Non-Invasive in-Flight Intracranial Pressure Measurement

Introduction: In certain emergency situations, a patient admitted to a hospital with fewer resources needs to be transferred quickly to a unit better prepared to deal with them. This is when the aeromedical transport service is needed. For this, the aircraft must be staffed by specialized health professionals and have a variety of resources to provide the best care for the patient. Objectives: 1) The general objective of this article was to analyze changes in intracranial pressure (ICP) in Brazilian Air Force pilots undergoing a level straight flight. 2) To help collect data for the development of a non-invasive sensor for monitoring ICP in flight. 3). To verify whether the equipment for measuring non-invasive Intracranial Pressure can be used in air ICUs. Materials and Methods: The work evaluated the presence of morphological changes in non-invasive ICP during level straight flight lasting 30 min among 10 (ten) pilots who volunteered for the collection. Results: It was observed that the ICP pulse waveform did not change during straight level flight, when compared to normal resting situations of an individual in a collection in a terrestrial environment, demonstrating the reliability of the equipment and the research. Final considerations: This study has helped to understand not only the need for rapid diagnosis of non-invasive ICP, but also the possible suitability of this equipment in aircraft prepared for rapid diagnosis and tratament.

Ascent phase convective heat transfer of a stratospheric-balloon-borne payload

Stratospheric ballooning flights are becoming more relevant due to these platforms can place payloads to an altitude above almost 99% of the atmosphere, where the environmental conditions are very similar to the space ones. From a thermal point of view, during the ascent phase convection is very relevant and, despite what a priori may be thought, depending on the element considered, convection may not be negligible at the float phase. With this in mind, the Thermal Analysis Support and Environment Characterization Laboratory (TASEC-Lab) was born. It is an experiment based on COTS, which consists in a 3U CubeSat-like experiment, which was launched onboard a stratospheric balloon in León (Spain) on 16th, July 2021. The upper unit of the 3U box contains a heated plate, with the aim of quantifying the relevance of convection during the flight. In this paper, the relevance of convection during the ascent phase is described, the correlation of in-flight temperature measurements with those provided by the thermal mathematical model developed in ESATAN-TMS is performed, using the air mass flow inside the cavity as a fitting parameter with a fitting error lower than 5 °C during the ascent phase.

Monocular In-flight Measurement of Airfoil Deflections

The knowledge of the actual shape of an aeroplane’s wing in midair is crucial to perform realistic flow simulations. Based on these analyses, the shape of a wing can be optimized by constructive measures and by the selective emptying of the fuel tanks installed inside the wings. As a result, the fuel consumption is reduced and fewer emissions occur. Furthermore, monitoring wing deflections allows for conclusions about the mechanical load and thus the service limit of an airfoil. To determine the wing deflection, we present the concept of a deployed measuring system consisting of measuring marks attached to the wing’s surface and a single camera. A basic model for the bending of a wing is explained and utilized, which assumes the preservation of arc lengths on the wing’s upper surface during bending. The measuring system was successfully applied during several long-distance flights with wide-body aircraft. The design of the measurement system, its setup and calibration, as well as obtained results are presented and discussed.

Honey bee flights near hover under ethanol-exposure show changes in body and wing kinematics.

Flying social insects can provide model systems for in-flight interactions in computationally-constrained aerial robot swarms. The social interactions in flying insects may be chemically modulated and quantified via recent measurement advancements able to simultaneously make precise measurements of insect wing and body motions. This paper presents the first in-flight quantitative measurements of ethanol-exposed honey bee body and wing kinematics in archival literature. Four high-speed cameras (9000 frames/sec) were used to record the wing and body motions of flying insects (Apis mellifera) and automated analysis was used to extract 9000 frame/sec measurements of honey bees' wing and body motions through data association, hull reconstruction, and segmentation. The kinematic changes induced by exposure to incremental ethanol concentrations from 0% to 5% were studied using statistical analysis tools. Analysis considered trial-wise mean and maximum values and gross wingstroke parameters, and tested deviations for statistical significance using Welch's t-test and Cohen's d test. The results indicate a decrease in maximal heading and pitch rates of the body, and that roll rate is affected at high concentrations (5%). The wingstroke effects include a stroke frequency decrease and stroke amplitude increase for 2.5% or greater concentrations, gradual stroke inclination angle increase up to 2.5% concentration, and a more planar wingstroke with increasing concentration according to bulk wingstroke analysis. These ethanol-exposure effects provide a basis to separate ethanol exposure and neighbor effects in chemically mediated interaction studies.