Field Of Regard Research Articles

High-precision and large-range deflection of light beams with fast steering mirrors.

Fast steering mirrors (FSMs) offer a potential alternative for large-range deflection of light beams. However, for a large-stroke FSM, its pointing precision is unacceptably deteriorated due to the actuator non-uniformity, mechanical axis coupling, and the coupling of line-of-sight (LOS) kinematics. This Letter proposes a comprehensive beam-pointing algorithm by decoupling the LOS kinematic model and establishing a two-dimensional correction mapping to compensate for the non-uniformity and mechanical coupling. Moreover, the incident angle is calibrated by a non-contact method to construct the LOS kinematic model accurately. The experimental results proved that the beam-pointing accuracy can achieve a sub-milliradian level within the square field of regard (FOR) of ±25° horizontally and ±14° vertically. A pointing error of 0.87 mrad can be guaranteed within the horizontal range of -30° to 36° and the vertical range of ±24°. Therefore, the proposed method can achieve high-precision beam pointing in a large FOR and contributes to the miniaturization of optical systems.

The Evaluation of FY-3E Hyperspectral Infrared Atmospheric Sounder-II Long-Wave Temperature Sounding Channels

Prior to assimilating hyperspectral infrared data on the FengYun (FY) satellite in the numerical weather prediction (NWP) system, it is necessary to identify the quality and bias characteristics of these data, especially as China’s first early-morning-orbit satellite data. Using the numerical model CMA-GFS (China Meteorological Administration Global Forecast System) and the observation of FY-3E HIRAS-II (Hyperspectral Infrared Atmospheric Sounder-II), the differences between observed and simulated brightness temperatures (O-Bs) are comprehensively analyzed, with a focus on evaluating the long-wave (LW) temperature sounding channels of HIRAS-II observation in the clear sky. The results show that the O-Bs in the LW channels are between ±1.0 K, except for the CO2 absorption line peak at 667 cm−1. Only a tiny variation in O-Bs, with relative consistency, could be observed during the day, the line of dawn and dusk, and night. The difference in the standard deviations of O-Bs in the three cases is less than 0.1 K. The O-Bs of two typical channels (channels 14 and 47) in the stratosphere have disturbances at individual times, whereas the O-Bs are much more stable in time series in the tropospheric channels. The O-Bs in different channels show the characteristics of changing with the latitude, but the bias and standard deviations of O-Bs during the ascending and descending stages are not much different, except for the bias of channel 47 in low latitude. The optimal ranking of Fields of View (FOVs) in assimilation is derived from a priori analysis of O-Bs. The results demonstrate that FOV4 and FOV5 are the best in a Field of Regard (FOR) compared to all LW channels of HIRAS-II in constructions of their O-Bs and magnitude of O-B standard deviations, and they can be used as the preferred FOVs for assimilation. While the O-Bs in FOV1 and FOV2 are slightly larger, the O-Bs’ characteristics also meet the assimilation requirements and can be used as assimilation FOVs in HIRAS-II LW channels after FOV4 and FOV5 lose their efficacy.

Diversity in the United Kingdom: Quantification for higher education in comparison to the general population

AbstractDiversity in the United Kingdom is regularly quantified through Census data. The latest figures (2021) for England and Wales indicate that 82% of the population identifies as white, 51% are females, 17.7%–22.3% are disabled, 18.2% hold no qualifications and 51.7% of households are deprived in at least one dimension. Furthermore, the median age in England and Wales is 40. All of these figures vary significantly across local geographical areas. Diversity in Higher Education (HE) is also monitored yearly by the Office for Students. The latest figures (2020/2021) indicate that 68.4% of entrants are under 21 years old, 56.5% are females, 14.8% report a disability and 21.8% are categorized as severely deprived. Some differences were observed between these figures and those from previous years. The current study aims to highlight how diversity in HE has evolved since 2010 and how the current landscape can illustrate significant differences between courses. Furthermore, comparisons with the general population are also measured in an attempt to describe potential bias in HE, together with new avenues that should be explored to level the HE field in regard to diversity. Our results indicate that access to HE needs to be improved for males, while strong discrepancies were observed between disciplines. Ethnic diversity remains high throughout the HE sector, although subject‐specific biases were noted. An increase in students from the most deprived areas has been found, although it was not the case for all subjects within the sector. Finally, reported disabilities are on the rise, especially regarding mental health, warranting additional support for affected students. These findings are discussed and put into context. To conclude, HE providers might need to collegially address subject‐specific discrepancies.

The use of a 4.7 mg deslorelin slow release implant in male dogs in the field.

Slow-release GnRH agonist implants (SRI) are used for reversible medical downregulation of testicular function in male dogs as an alternative to surgery. The 4.7 mg deslorelin SRI should reduce testosterone after 6-8 weeks and induce castration-like effects for 6 months (mon). However, some individual variation is described in the field in regard to onset and duration of effect. For this reason, we aimed to study the effects of the 4.7 mg deslorelin SRI in a larger cohort. In total 50 intact, healthy male dogs (12-48 months, mon; 9-40 kg) were treated with a 4.7 mg deslorelin SRI into the umbilical area (TG, n=45) or served as untreated controls (CG, n=5). CG dogs were surgically castrated after measurement of testicular dimensions and blood sampling for testosterone. In TG, SRIs remained for 5 mon in place and subsequently 3-7 male dogs were surgically castrated at removal (week, W 0) or 1, 2, 3, 4, 5, 6, 7, 8 or 10 weeks later. Examination parameters were testicular dimensions (before treatment, at 4, 8, 12 W, 5 mon, weekly until castration), testosterone (before treatment, at 8 W, 5 mon, castration) and testicular histology (castration). Whereas examination parameters did not differ between CG and TG before treatment, testicular volume and testosterone was significantly reduced at all time points during treatment. In all but 3 (8 W) and 2 male dogs (5 mon) testosterone was basal during treatment before removal, whereas the parameters were significantly reduced compared to pre-treatment in the respective dogs. After implant removal, testosterone and testicular volumes increased. However, different to earlier studies, the "restart" was more variable with individual basal testosterone until W7, but also physiological testosterone concentrations in W2. Similarly, histological testicular findings at castration were quite variable: besides an arrest on spermatogonia and spermatocytes, elongated spermatids with normal spermatogenesis were found in individual dogs. Our study confirms the efficacy of the deslorelin SRI, but also individual variation especially regarding reversibility of effects on endocrine and germinative testicular function. Deslorelin SRIs offer a suitable alternative to surgical castration with individual variation to be considered when used in clinical practice.

Feasibility of hemispatial neglect rehabilitation with virtual reality-based visual exploration therapy among patients with stroke: randomised controlled trial.

Hemispatial neglect (HSN) was diagnosed using a virtual reality-based test (FOPR test) that explores the field of perception (FOP) and field of regard (FOR). Here, we developed virtual reality-visual exploration therapy (VR-VET) combining elements from the FOPR test and visual exploration therapy (VET) and examined its efficacy for HSN rehabilitation following stroke. Eleven participants were randomly assigned to different groups, training with VR-VET first then waiting without VR-VET training (TW), or vice versa (WT). The TW group completed 20 sessions of a VR-VET program using a head-mounted display followed by 4 weeks of waiting, while the WT group completed the opposite regimen. Clinical HSN measurements [line bisection test (LBT), star cancellation test (SCT), Catherine Bergego Scale (CBS), CBS perceptual-attentional (CBS-PA), and CBS motor-explanatory (CBS-ME)] and FOPR tests [response time (RT), success rate (SR), and head movement (HM) for both FOP and FOR] were assessed by blinded face-to-face assessments. Five and six participants were allocated to the TW and WT groups, respectively, and no dropout occurred throughout the study. VR-VET considerably improved LBT scores, FOR variables (FOR-RT, FOR-SR), FOP-LEFT variables (FOP-LEFT-RT, FOP-LEFT-SR), and FOR-LEFT variables (FOR-LEFT-RT, FOR-LEFT-SR) compared to waiting without VR-VET. Additionally, VR-VET extensively improved FOP-SR, CBS, and CBS-PA, where waiting failed to make a significant change. The VR-VET made more improvements in the left hemispace than in the right hemispace in FOP-RT, FOP-SR, FOR-RT, and FOR-SR. The observed improvements in clinical assessments and FOPR tests represent the translatability of these improvements to real-world function and the multi-dimensional effects of VR-VET training. https://clinicaltrials.gov/ct2/show/NCT03463122, identifier NCT03463122.

Characterization of the East—West Spatial Uniformity for GOES-16/17 ABI Bands Using the Moon

The Advanced Baseline Imager (ABI) is the primary instrument onboard the NOAA Geostationary Operational Environmental Satellite-R Series (GOES-R) satellites, providing continuous weather imagery over the vast area in the Western Hemisphere. It is imperative to ensure consistent calibration accuracy within the instrument’s field of regard (FOR). This paper characterized the spatial uniformity in the east–west (EW) direction for the six ABI visible and near-infrared (VNIR) bands of the first two GOES-R satellites, GOES-16 (G16) and GOES-17 (G17), using a special collection of lunar chasing images during their post-launch testing and post-launch product testing (PLT/PLPT) periods. The EW response versus scan-angle (RVS) is examined with the normalized lunar irradiance ratios at varying scan angles combined from multiple lunar-chasing events. The impacts of straylight from the Earth were found in some of the B01–B03 lunar images. The straylight, including those scattered into the spacelook scenes near the polar regions and those leaked into space near the Moon, can cause RVS variation up to 1% for B01 and to a lesser magnitude for the other two bands. Straylight correction algorithms are applied for the accurate ABI lunar image irradiance calculation. After the corrections, the RVS variation is reduced to less than 0.3% for all the VNIR bands of both G16/17 in full-disk (FD) images. Results of this study also confirm that the Global Space-based Inter-Calibration System (GSICS) Implementation of the ROLO (GIRO) model has high relative accuracy for the ABI VNIR bands when the lunar images are collected within a relatively short time. The method described in this paper can be applied to validate the EW spatial uniformity for imagers on other geostationary satellites, including the recently launched GOES-18 and the future GOES-U satellites.

Space-Based Sensor Tasking Using Deep Reinforcement Learning

To maintain a robust catalog of resident space objects (RSOs), space situational awareness (SSA) mission operators depend on ground- and space-based sensors to repeatedly detect, characterize, and track objects in orbit. Although some space sensors are capable of monitoring large swaths of the sky with wide fields of view (FOVs), others—such as maneuverable optical telescopes, narrow-band imaging radars, or satellite laser-ranging systems—are restricted to relatively narrow FOVs and must slew at a finite rate from object to object during observation. Since there are many objects that a narrow FOV sensor could choose to observe within its field of regard (FOR), it must schedule its pointing direction and duration using some algorithm. This combinatorial optimization problem is known as the sensor-tasking problem. In this paper, we developed a deep reinforcement learning agent to task a space-based narrow-FOV sensor in low Earth orbit (LEO) using the proximal policy optimization algorithm. The sensor’s performance—both as a singular sensor acting alone, but also as a complement to a network of taskable, narrow-FOV ground-based sensors—is compared to the greedy scheduler across several figures of merit, including the cumulative number of RSOs observed and the mean trace of the covariance matrix of all of the observable objects in the scenario. The results of several simulations are presented and discussed. Additionally, the results from an LEO SSA sensor in different orbits are evaluated and discussed, as well as various combinations of space-based sensors.

The NASA TEMPO Mission: Revolutionary Satellite Observations for Community-Scale Air Quality Monitoring and Improved Health Studies

In December 2022, NASA plans to launch the Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument, a geostationary ultraviolet/visible grating spectrometer, which will observe trace gases and aerosols, including nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (HCHO), ozone (O3), and aerosol optical depth (AOD), at high spatial resolution (~2 x 4.75 km2) every daylight hour over a Field of Regard (FoR) covering greater North America. An O3 profile product from TEMPO will provide information on O3 in the 0-2 km layer where people live and breathe. TEMPO will also enable observations at even higher frequency (e.g., <= 10 minutes) over smaller regions during special non-standard scan operations. During the pre-launch era of the TEMPO mission, a large diversity of stakeholders and end-users have participated in workshops, data tutorials, and focus sessions hosted by the TEMPO Early Adopters Program, supported by the NASA Applied Sciences Program (ASP), which aims to maximize the societal benefit of the mission data after launch. These user engagement activities have led to a comprehensive understanding of the unprecedented air quality and health applications that can be achieved through use of the highly anticipated data products. In particular, the TEMPO mission will provide multi-pollutant data at high spatiotemporal resolution for enabling more robust and accurate health studies and exposure assessments. This presentation will provide details on the current status of the TEMPO mission, Early Adopter Program activities, and science applications and demonstrations relevant to the epidemiology community. Keywords: air quality, health, satellites

Optical design of the Orbiting Astronomical Satellite for Investigating Stellar Systems

The Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS) is a proposed space telescope with a 14-m inflatable primary reflector that will perform high spectral resolution observations at terahertz frequencies with heterodyne receivers. The telescope consists of an inflatable metallized polymer membrane that serves as the primary antenna, followed by aberration correction optics, and a scanner that enables a 0.1-deg field of regards while achieving diffraction-limited performance over wavelength range from 63 to 660 μm. Here, the parametric solution space of the OASIS inflatable telescope design is systematically investigated by establishing analytical relations among figure of merits including first-order geometrical photon collection area and the size of correction optics. The first-order solution was further optimized by ray-trace code by incorporating numerically calculated mirror shape with preformed membrane gores. Design study shows that a space-based telescope with an effective photon collection area of over 90 m2 can be achieved by utilizing a 14-m inflatable aperture.

Numerical analysis for characterizing hydrogen embrittlement behaviors induced in STS316L stainless steel using an in-situ small-punch test

In-situ small-punch (SP) tests have recently been used to characterize the susceptibility to hydrogen embrittlement (HE) of various steels. Most techniques for HE evaluation have been based on the use of initially hydrogen pre-charged specimens. However, in internal hydrogen conditions, consistent results are not obtained for the embrittlement and fracture behavior in comparison to those under external hydrogen conditions. In this study, an in-situ SP test was used to evaluate the HE susceptibility in 316L austenitic stainless steel. The test was carried out in 10-MPa gas environments at room temperature (RT) and below with different punch velocities. The results showed that at 10-MPa H2 gas, STS316L steel exhibited good resistance to HE at RT and −10 °C. However, the susceptibility to HE depended on the test temperature and punch velocity. A numerical simulation of the SP test was used to systematically compensate for the insufficient explanation of the crack formation that occurred during in-situ SP testing and to investigate the interaction of the punch velocity and the stress field in regard to the HE effect. The numerical analysis results support the experimental findings and provide a detailed explanation of factors such as the friction coefficient, strain rate, and stress state which lead to crack formation through their interaction in hydrogen-embrittled steel.

Are we ready for PD prevention studies?

Over the last two decades a substantial progress has been made in understanding of Parkinson's disease biology and natural history. Most relevantly, the syndrome of premotor (prodromal) manifestations (hyposmia, REM behavior disorder, sleep, autonomic dysfunction among the others) and genetic risk factors have been well defined. On the other hand, not a single disease modifying trial had a positive effect on disease progression despite multiple trials. One of the potential explanations of the recent failures is late timing of intervention as newly diagnosed PD is already associated with significant loss of dopaminergic and other neurons. Constellation of recent failures and better understanding of the scope and natural course of prodromal phase of the disease pave the way to disease prevention studies. Such studies will target prodromal population and test efficacy of intervention to prevent pphenoconversion to clinically defined alpha- synucleinopathy. In order to plan such studies, we need to define the population (WHO), intervention (WHAT) and finally how to measure success (HOW). While a number of observational studies have provided substantial data on the risk of pheconversion in prodromal cohorts to clinically defined a-synucleinopathy, still the challenges remain. An essential aspect of readiness for disease prevention studies is a number of ethical and feasibility considerations of testing interventions in prodromal at-risk participants who do not have disability or clinically defined disease. This presentation will review the state of the field in regard to readiness for PD prevention studies and outline future directions.

The different types of reports produced in digital forensic investigations

The importance of ensuring the results of any digital forensic (DF) examination are effectively communicated cannot be understated. In most cases, this communication will be done via written report, yet despite this there is arguably limited best practice guidance available which is specific for this field in regards to report construction. Poor reporting practices in DF are likely to undermine the reliability of evidence provided across this field, where there is a need for formalised guidance regarding the requirements for effective DF report construction; this should not be a task left solely to each individual practitioner to determine without instruction. For this, the field of DF should look to the wider forensic community and the existing work in this area for support. In line with many other ‘traditional’ forensic science types, a DF practitioner can be commissioned to report in one of three ways - ‘technical’, ‘investigative’ or ‘evaluative’, where each reporting type maintains a specific purpose and interpretative-context, determined by the examination workflow undertaken by a practitioner following client instruction. This work draws upon guidance set out in fundamental forensic science reporting literature in order to describe each reporting type in turn, outlining their scope, content and construction requirements in an attempt to provide support for the DF field.

Judicial practices of the Eastern Christian saints in the beginning of the IV – middle of the V centuries

This article is dedicated to the study of activity of the saints in the area of justice during the Late Antiquity, and is structured upon the examination of theirs hagiographical works. The period of Late Antiquity, with its peculiar attitude towards the questions of crime and punishment and their social meaning is virtually out of the field of regards of modern historians. This article places emphasis no so much on the legal issues as on the social aspects of the practice of saints. The object of this research is the phenomenon of the saint, which emerged on the East of the Late Roman in the early IV century with the advent of the Christian monasticism and asceticism. The subject of this research is the practical activity of the saints associated with dispute settlement, conflict resolution, and crime prevention. The conclusion is made that the judicial activity of the saint reflects the perspective on justice that differs from the traditional systems. The saint uses an informal mechanism of mediation for reconcilement of adversaries and bringing them to a compromise. It is based on the need for a new outlook upon the problem of aggression that existed in society of the Late Antiquity, as key source of criminality. The actions of the saint are aimed at alleviation of human aggressiveness and rejection of violence and policy of frightening that were typical at that time, thereby preventing the offender from committing an offence. The main instrument in activity of the saint is the ability to accomplish a miracle, which reflects the power of the saint to overcome the traditional principles of justice.

HEALTH COACHING SUCCESS TIPS : A LITERATURE REVIEW

Health coaching is a way of expanding the scope of health services through health promotion and disease prevention efforts by giving information in order to improve preventive behaviour in the community. The success of health coaching is determined by health workers’ understanding of the influencing factors. However, not many researches have been done in this area. Outlining evidence-based information within nursing field in regard to factors that determine the success of health coaching. This study is a non-systematic literature review analysing 10 related journals. The success of health coaching is determined by several factors including, agreement between both parties, good trainer (confidence, responsible, thorough, and appreciative), supportive trainer, motivated patients, collaboration between trainer and patients, good communication skills, frequency and duration of interaction between them. Several studies conducting telephone-based health coaching showed a significant success in converting patients’ behaviour into preventive behaviour.
 
 Keywords: Health Coaching; Health Promotion; Disease Prevention; Literature Review

FOPR test: a virtual reality-based technique to assess field of perception and field of regard in hemispatial neglect

BackgroundWe previously proposed a novel virtual reality-based method to assess human field of perception (FOP) and field of regard (FOR), termed the FOPR test. This study assessed the diagnostic validity of the FOPR test for hemispatial neglect (HSN).MethodsWe included 19 stroke patients with a lesion in the right hemisphere and with HSN (HSN+SS), 22 stroke patients with a lesion in the right hemisphere and without HSN (HSN−SS), and 22 healthy controls aged 19–65 years. The success rate (SR) and response time (RT) in the FOPR test for both FOP and FOR were assessed (FOP-SR, FOR-SR, FOP-RT, and FOR-RT, respectively). Using a Bland–Altman plot, agreements between the FOPR test and conventional tests were confirmed, and the FOPR test accuracy was verified using the support vector machine (SVM). Measured values were analysed using ANOVA and Kruskall–Wallis tests for group comparison.ResultsThe Bland–Altman plot showed good agreement between FOPR test and conventional tests; individuals within 95% agreement limits were within the range of 94.8–100.0%. The SVM classification accuracy, using FOP and FOR variables from the left hemispace, ranged from 83.3 to 100.0% in a binary classification (HSN vs non-HSN). The FOPR test demonstrated differences in SR and RT for both FOP and FOR across the groups.ConclusionThe FOPR test was valid for the HSN diagnosis and provided quantitative and intuitive information regarding visuospatial function. Furthermore, it might enhance our understanding of visuospatial function including HSN by applying the time relative component and concepts of perception and exploration, FOP and FOR.Trial registration: NCT03463122. Registered 13 March 2018, retrospectively registered.

Experiences with Fibre Ropes as Hoist Ropes in Crane Applications

High strength polymer fibres are opening new fields in regard on their strength to weight ratio. In 2009 Liebherr and Teufelberger started a development partnership to utilise these opportunities and rethink the basics of hoist ropes for cranes: (1) Introduction; (2) The high strength fibre rope soLITE; (3) Load bearing capacity of the rope; (4) Liebherr fibre crane series; (5) Discard criteria.

Effect of Playing Position, Match Half, and Match Day on the Trunk Inclination, G-Forces, and Locomotor Efficiency Experienced by Elite Soccer Players in Match Play.

The rapid growth of wearable sensors has allowed the analysis of trunk kinematics during the match, which is necessary for having a better understanding of the postural demands of soccer players. However, some contextual variables may have an impact on the physical demands of the players. This study aimed to analyze the effect of three contextual variables (playing position, match half, and match day) on the sagittal trunk inclination, G-forces, and locomotor efficiency experienced by soccer players in match play. Then, wearable sensors were used to collect the trunk kinematics during 13 matches. Firstly, positional differences were found on the trunk inclination (p = 0.01) and the G-forces experienced by the players (p < 0.001). For example, the greatest and lowest trunk inclination was found for FW (~34.01°) and FB (~28.85°) while the greatest and lowest G-forces were found for WMF (1.16 G) and CD (1.12 G), respectively. However, there were no positional differences in the locomotor efficiency (p = 0.10). Secondly, the match half had a significant effect on the trunk inclination (p = 0.01) and the G-forces experienced by the players (p < 0.001) with significantly lower values observed during the second half. No differences between halves were found on the locomotor efficiency for any playing position (p = 0.41). Finally, no significant effect of match day on any variable was observed. This investigation is one of the first steps towards enhancing the understanding of trunk kinematics from elite soccer players. The positional differences found on the trunk inclination and G-forces imply that the development of position-specific training drills considering the postural demands is necessary to prepare the players not only for the physical demands but also for successful performance in the field of regard. The resistance to fatigue needs to be trained given the differences between halves.

Лексикализация семантических полей ‘бросание’ и ‘падение’ в тамильском языке

The paper examines the lexicalization of contiguous semantic fields — FALLING and THROWING — in Tamil. The data obtained from native speakers as well as from dictionaries and written sources is considered. Lexical units of FALLING semantic field are investigated with the help of a questionnaire developed within the project and used for all the papers of this volume. The THROWING semantic field is less described. Our research is based on the questionnaire worked out in [Ivtushok 2015] which is adapted to Tamil data. Related with quasi-causative bond, these fields demonstrate different semantic strategies of their lexification. The FALLING field is organized as a strongly dominant zone, while the THROWING field is covered by three main verbs and several more peripheral ones. The main lexeme describing the semantics of FALLING in Tamil (the dominant verb of the field) is viẓu. It is supported by a number of verbs with considerably restricted meanings: pey (“rainfall” and other natural phenomena), utir (‘falling of leaves and similar objects’), koṭṭu (‘loss of teeth, hair’), citaṟu (‘falling with scattering in different directions’), cintu (‘uncontrolled downward movement of liquids, including liquid drops’), naẓuvu (‘falling with slipping’) and some others. In the THROWING semantic field the main verbs er̠i (‘to throw with an eff ort to the target’), vīcu (‘to throw with less effort as a wide sweeping movement’) and pōṭu (‘to throw from a short distance with accuracy’) are also accompanied by peripheral ones, like ey (‘to throw a light object’, ‘to launch, as an arrow’), ir̠ai (‘to scatter a multiple object to the sides, as to sow grain’). In addition to THROWING frames suggested in [Ivtushok 2015], such as “throwing at a target”, “throwing up”, “throwing down”, “multiple object throwing”, “throwing inside a container” etc., the paper proposes some new frames describing this semantic field in regards to Tamil data, such as ‘throwing at a target with resistance overcoming’ or ‘throwing with a wide, sweeping movement without overcoming resistance’.

High Spectral Infrared Atmospheric Sounder (HIRAS): System Overview and On-Orbit Performance Assessment

The High Spectral Infrared Atmospheric Sounder (HIRAS) is the first Chinese Fourier Transform Michelson interferometer onboard the FengYun 3D (FY-3D) polar-orbiting meteorological satellite launched on November 15, 2017. The FY-3D HIRAS provides infrared (IR) radiance spectra measurements in three spectral bands: the long-wave IR (LWIR) band from 650 to 1135 cm−1, middle-wave IR (MWIR) band from 1210 to 1750 cm−1, and short-wave IR (SWIR) band from 2155 to 2550 cm−1. The ground system processes the interferogram measurements into calibrated radiance spectra. In each cross-track scan, there are 29 observations, each with a field-of-regard (FOR) comprising an array of $2\times 2$ field of views. In a six-month intensive campaign period, the HIRAS system was tuned, characterized, and validated. For the operational Level 1 product, the radiance noise levels meet the specifications. The spectral frequency accuracy was improved by maximizing the spectral correlation between the measured and simulated spectra by tuning the instrument-line-shape parameters. The absolute spectral frequency biases are less than 3 part per million (ppm) for all the three bands, and spectral bias standard deviations are less than 3 ppm in the LWIR and MWIR bands, and are about 3–5 ppm in the SWIR band. The radiometric calibration uncertainties were assessed by the comparisons of the radiance spectra between HIRAS and other IR hyperspectral sensors on different satellites. The radiance differences of the cross-sensor comparisons are in general less than 0.3, 0.7, and 1.0 K in the LWIR, MWIR, and SWIR bands, respectively. The HIRAS spectra were also compared with the spectra simulated with a fast radiative transfer model. Some remaining issues for the FY-3D HIRAS are also discussed.

The rack orientation and curvature problem for retailers

The layout of a retail store directly affects the products to which shoppers are exposed, and ultimately their purchase. Optimizing a layout to increase product visibility can directly benefit both the retailer (via increased revenue) and the shopper (via increased satisfaction). We introduce the Rack Orientation and Curvature Problem, which determines the orientation and curvature of each rack in a layout to maximize the expected marginal impulse profit (after discounting for floor space cost). We account for the dynamic interaction between a walking shopper’s field of regard and a layout of racks filled with products. As several constraints in the optimization model cannot be expressed in a closed analytical form, we propose a particle swarm optimization-based solution approach and, subsequently, conduct a comprehensive experimental study using realistic data. Layouts with either high-acute and straight-to-medium-curved racks, or high-obtuse and high-curved racks, appear to dominate common rack layouts with orthogonal and straight racks; increases of over 23% can be realized depending on the location policy of products. Sensitivity of these solutions to shopper volume, cost of floor space, travel direction, and aspect ratio is also evaluated. Retailers can use our approach to quantitatively evaluate new rack designs or benchmark existing ones.