Parallelization of a new embedded application for automatic meteor detection

This article presents the methods used to parallelize a new computer vision application. The system is able to automatically detect meteor from non-stabilized cameras and noisy video sequences. The application is designed to be embedded in weather balloons or for airborne observation campaigns. Thus, the final target is a low power system-on-chip (< 10 Watts) while the software needs to compute a stream of frames in real-time (> 25 frames per second). For this, first the application is split in a tasks graph, then different parallelization techniques are applied. Experiment results demonstrate the efficiency of the parallelization methods. For instance, on the Raspberry Pi 4 and on a HD video sequence, the processing chain reaches 42 frames per second while it only consumes 6 Watts.Comment: in French language, COMPAS 2023 - Conf{\'e}rence francophone d'informatique en Parall{\'e}lisme, Architecture et Syst{\`e}me, Jul 2023, Annecy (France), Franc

Une nouvelle application de détection de météores robuste aux mouvements de caméra

International audienceThis article presents a new tool for the automatic detection of meteors. Fast Meteor Detection Toolbox (FMDT) is able to detect meteor sightings by analyzing videos acquired by cameras onboard weather balloons or within airplane with stabilization. The challenge consists in designing a processing chain composed of simple algorithms, that are robust to the high fluctuation of the videos and that satisfy the constraints on power consumption (10 W) and real-time processing (25 frames per second).Cet article présente un nouvel outil pour la détection automatique des météores nommé Fast Meteor Detection Toolbox (FMDT) qui est capable de détecter des météores entrant dans l'atmosphère terrestre en analysant des vidéos acquises avec des caméras embarquées à bord d'un ballon-sonde ou stabilisées dans un avion. Le défi est de concevoir une chaîne de traitement composée d'algorithmes simples tout en étant robustes à une grande variabilité de vidéos et en respectant des contraintes de consommation (10 W) et de temps réel (25 images par seconde)

A 2022 τ-Herculid meteor cluster from an airborne experiment: automated detection, characterization, and consequences for meteoroids

International audienceContext. The existence of meteor clusters has long since been a subject of speculation and so far only seven events have been reported, among which two involve less than five meteors, and three were seen during the Leonid storms.Aims. The 1995 outburst of Comet 73P/Schwassmann-Wachmann was predicted to result in a meteor shower in May 2022. We detected the shower, proved this to be the result of this outburst, and detected another meteor cluster during the same observation mission.Methods. The τ-Herculids meteor shower outburst on 31 May 2022 was continuously monitored for 4 hours during an airborne campaign. The video data were analyzed using a recently developed computer-vision processing chain for meteor real-time detection. Results. We report and characterize the detection of a meteor cluster involving 38 fragments, detected at 06:48 UT for a total duration of 11.3 s. The derived cumulative size frequency distribution index is relatively shallow: s = 3.1. Our open-source computer-vision processing chain (named FMDT) detects 100% of the meteors that a human eye is able to detect in the video. Classical automated motion detection assuming a static camera was not suitable for the stabilized camera setup because of residual motion.Conclusions. From all reported meteor clusters, we crudely estimate their occurrence to be less than one per million observed meteors. Low heliocentric distance enhances the probability of such meteoroid self-disruption in the interplanetary space

A 2022 τ-Herculids meteor cluster

International audienceAirborne observation (see J. Toth’s talk)Mobile cameras from the MoMet device (see Da Fonseca’s talk, IMC2021)2 stabilized cameras + RBpi + RMS software2 unstabilized cameras + continuous recording on MacBasler acA1920-155um + 6mm f/1.4 or 12mm f/1.6 lens ; 20 fp

A 2022 τ-Herculids meteor cluster

International audienceAirborne observation (see J. Toth’s talk)Mobile cameras from the MoMet device (see Da Fonseca’s talk, IMC2021)2 stabilized cameras + RBpi + RMS software2 unstabilized cameras + continuous recording on MacBasler acA1920-155um + 6mm f/1.4 or 12mm f/1.6 lens ; 20 fp

Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19

BackgroundWe previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in similar to 80% of cases.MethodsWe report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.ResultsNo gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P=1.1x10(-4)) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70[95%CI 1.3-8.2], P=2.1x10(-4)). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR=19.65[95%CI 2.1-2635.4], P=3.4x10(-3)), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR=4.40[9%CI 2.3-8.4], P=7.7x10(-8)). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10(-5)).ConclusionsRare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old