Local Catalog Research Articles

Bayesian earthquake forecasting approach based on the epidemic type aftershock sequence model

The epidemic type aftershock sequence (ETAS) model is used as a baseline model both for earthquake clustering and earthquake prediction. In most forecast experiments, the ETAS parameters are estimated based on a short and local catalog, therefore the model parameter optimization carried out by means of a maximum likelihood estimation may be not as robust as expected. We use Bayesian forecast techniques to solve this problem, where non-informative flat prior distributions of the parameters is adopted to perform forecast experiments on 3 mainshocks occurred in Southern California. A Metropolis–Hastings algorithm is employed to sample the model parameters and earthquake events. We also show, through forecast experiments, how the Bayesian inference allows to obtain a probabilistic forecast, differently from one obtained via MLE.Graphical

Offshore Fault Geometry Revealed from Earthquake Locations Using New State-of-Art Techniques: The Case of the 2022 Adriatic Sea Earthquake Sequence

Abstract Precise hypocenter locations are critical for properly interpreting earthquake occurrence processes. However, when the coverage with seismic stations is unfavorable or sparse, locating precisely earthquake hypocenters, in particular their depth, is challenging. Here we apply a newly developed approach, which uses only two land stations, to the recently occurred 2022 Adriatic Sea offshore earthquake sequence (mainshock of magnitude Mw 5.5) and achieve location results that are comparable to the catalog locations obtained using dozens of stations. First, six events with magnitudes M ≥3.0 were relocated using a travel-time stacking method. Next, using these six earthquakes as reference events, we applied a two-station differential travel-time method to reconstruct the earthquake cluster geometry and locate the remaining events, including the mainshock. The obtained earthquake distribution shows a dipping direction that varies from south to southwest, depending on the choice of the input parameters. Our preferred result shows a cluster dipping at an angle of ∼30° toward the south-southwest. This solution was chosen because the depth of the mainshock hypocenter obtained using the differential-time procedure agrees well with the depth constrained using depth phases. Moreover, the relatively sharp earthquake cluster geometry is in general consistent with the thrust fault structures revealed by a local seismic reflection survey and focal mechanism solutions.

Wasatch Fault Structure from Machine Learning Arrival Times and High-Precision Earthquake Locations

Abstract On 18 March 2020, a magnitude 5.7 earthquake hit the Salt Lake valley in the state of Utah, United States. Using a dense geophone deployment and machine learning (ML), an additional several thousand events were detected and located. Currently, both the mainshock and the majority of the aftershocks are suspected to have occurred on or near a deeper portion of the Salt Lake segment of the Wasatch fault—part of a large range-bounding fault system thought to be capable of generating an Mw 7.2 earthquake. However, a small subset of aftershocks may have occurred on a portion of the more steeply, eastward dipping, and poorly understood West Valley fault. Unfortunately, the catalog locations and lack of focal mechanisms for this subset of aftershocks provide only a crude constraint on the true fault structure. To better illuminate fault structure, we relocate the ML-generated catalog with a range of magnitudes from −2 to 4.6, using: (1) NonLinLoc, a nonlinear location algorithm, (2) source-specific station terms, and (3) waveform coherence. We further compute first-motion focal mechanisms for 68 events. Results of the relocation suggest a simpler, minimally listric Wasatch fault geometry, contrary to what has been previously proposed. We also find that analysis of the focal mechanisms and waveform similarity indicates minimal event similarity throughout the Magna sequence, suggesting a highly complex and heterogeneous rupture zone, as opposed to rupture on a single plane. These findings suggest an increased seismic hazard due to the overall shallowness of the earthquake sequence and highly varied rupture mechanisms.

Analysis of the Use of E-Purchasing with Local Catalogs on the Performance of the Central Maluku Regency Government

E-purchasing is a method of procurement of goods and services whose process resembles the online shopping system that is rife today such as lazada.com, bukalapak.com, elevenia.com, and others. E-purchasing complements the method of procurement of government goods and services which previously consisted of general auction/selection, limited auction/selection, simple auction, direct appointment, direct procurement, contest and contest. This study aims to determine the effect of efficiency, effectiveness and transparency on the performance of procurement of goods through local catalogs. The population of this study are Procurement Officials, Commitment Making Officials in the Central Maluku Kabuapten Government, and local catalog users in Central Maluku Regency, as well as Goods/Services Providers involved in local catalogs. The sample was determined by purposive sampling technique, as many as 110 respondents. The analysis method used is the Structural Equation Model (SEM). The research variables are 4 latent variables consisting of 3 independent variables each efficiency, effectiveness and transparency and 1 (one) dependent variable namely performance. The results showed that efficiency, effectiveness and transparency had a positive and significant effect on the performance of procurement of goods through local catalogs.

Firmamento: A Multimessenger Astronomy Tool for Citizen and Professional Scientists

Firmamento (https://firmamento.hosting.nyu.edu) is a new-concept, web-based, and mobile-friendly data analysis tool dedicated to multifrequency/multimessenger emitters, as exemplified by blazars. Although initially intended to support a citizen researcher project at New York University–Abu Dhabi, Firmamento has evolved to be a valuable tool for professional researchers due to its broad accessibility to classical and contemporary multifrequency open data sets. From this perspective Firmamento facilitates the identification of new blazars and other multifrequency emitters in the localization uncertainty regions of sources detected by current and planned observatories such as Fermi-LAT, Swift, eROSITA, CTA, ASTRI Mini-Array, LHAASO, IceCube, KM3Net, SWGO, etc. The multiepoch and multiwavelength data that Firmamento retrieves from over 90 remote and local catalogs and databases can be used to characterize the spectral energy distribution and the variability properties of cosmic sources as well as to constrain physical models. Firmamento distinguishes itself from other online platforms due to its high specialization, the use of machine learning and other methodologies to characterize the data, and for its commitment to inclusivity. From this particular perspective, its objective is to assist both researchers and citizens interested in science, strengthening a trend that is bound to gain momentum in the coming years as data retrieval facilities improve in power and machine-learning/artificial-intelligence tools become more widely available.

SMatStack to Enhance Noisy Teleseismic Seismic Phases: Validation and Application to Resolving Depths of Oceanic Transform Earthquakes

AbstractThe depths of most moderate‐sized oceanic earthquakes are poorly constrained because of the lack of local recording stations and noisy teleseismic recordings. This hampers our understanding of slip behaviors along oceanic faults and the mechanical properties of the oceanic lithosphere. In this study, we develop a new method to enhance the weak body‐wave signals, particularly the depth phases, associated with earthquakes on oceanic transform faults using large‐aperture arrays in the teleseismic range. We simulate the enhanced teleseismic signals to refine the centroid depths of moderate‐sized earthquakes. We validate the new approach using synthetic waveforms and show it outperforms conventional methods when dealing with noisy signals. We obtain the depth estimates for three moderate‐sized earthquakes on the Chain transform fault in the equatorial Atlantic Ocean and find two of them are consistent with a local catalog derived using oceanic bottom seismometers. Application of the new method to the past decades of teleseismic recordings of moderate‐sized earthquakes on the large and slow‐slipping transform faults will provide significantly improved constraints on the width of the seismogenic zone, thus advancing our understanding of the rheology of oceanic lithosphere and earthquake processes in oceanic settings and, by comparison, their more dangerous continental counterparts. The new method is not limited to oceanic transform earthquakes, but can be easily adapted to other seismological studies in which noisy but coherent signals could be revisited for better usage.

A new seismicity catalogue of the eastern Alps using the temporary Swath-D network

Abstract. We present a new, consistently processed seismicity catalogue for the eastern and southern Alps based on the temporary dense Swath-D monitoring network. The final catalogue contains 6053 earthquakes for the time period 2017–2019 and has a magnitude of completeness of −1.0 ML. The smallest detected and located events have a magnitude of −1.7 ML. Aimed at the low to moderate seismicity in the study region, we have developed a multi-stage, mostly automatic workflow that combines a priori information from local catalogues and waveform-based event detection, subsequent efficient GPU-based (GPU: graphics processing unit) event search by template matching, P and S arrival time pick refinement, and location in a regional 3-D velocity model. The resulting seismicity distribution generally confirms the previously identified main seismically active domains but provides increased resolution of the fault activity at depth. In particular, the high number of small events additionally detected by the template search contributes to a denser catalogue and provides an important basis for future geological and tectonic studies in this complex part of the Alpine orogen.

Overview of Chinese medicinal materials industry in 2021 and development suggestions

This paper introduced the overview of the "eight trends" of Chinese medicinal materials(CMM) industry in 2021, analyzed the problems of CMM production, and put forward development suggestions. Specifically, "eight trends" could be summarized as follows.(1) The growing area of CMM tended to be stable, and some provinces began to release the local catalog of Dao-di herbs.(2) The protection process of new varieties accelerated, and a number of excellent varieties were bred.(3) The theory of ecological cultivation was further enriched, and the demonstration effect of ecological cultivation technology was prominent.(4) Some CMM realized complete mechanization and formed typical model cases.(5) The number of cultivation bases using the traceability platform increased, and provincial internet trading platforms were set up.(6) The construction of CMM industrial clusters accelerated, and the number of provincial-level regional brands increased rapidly.(7) Many new agricultural business entities were founded nationwide, and a variety of methods were used to drive the intensified development of CMM.(8) A number of local TCM laws were promulgated, and the management regulation of food and medicine homology substances catalogs was issued. On this basis, four suggestions for CMM production were proposed.(1) It is suggested to speed up the formulation of the national catalog of Dao-di herbs and carry out the certification of Dao-di herbs production bases.(2) Ecological planting of forest and grassland medicine should be further strengthened in terms of technical research and promotion based on the principle of ecological priority.(3) The basic work of disaster prevention should be paid more attention and technical measures for disaster mitigation should be developed.(4) The planted area of commonly used CMM should be incorporated into the national regular statistical system.

Seafloor Observations Eliminate a Landslide as the Source of the 1918 Puerto Rico Tsunami

ABSTRACT The 11 October 1918 devastating tsunami in northwest Puerto Rico had been used as an example for earthquake-induced landslide tsunami hazard. Three pieces of evidence pointed to a landslide as the origin of the tsunami: the discovery of a large submarine landslide scar from bathymetry data collected by shipboard high-resolution multibeam sonar, reported breaks of submarine cable within the scar, and the fit of tsunami models to flooding observations. Newly processed seafloor imagery collected by remotely operated vehicle (ROV) show, however, pervasive Fe–Mn crust (patina) on the landslide walls and floor, indicating that the landslide scar is at least several hundred years old. C14 dates of sediment covering the landslide floor verify this interpretation. Although we have not searched the region systematically for an alternative tsunami source, we propose a possible source—a two-segment normal-fault rupture along the eastern wall of Mona rift. The proposed fault location matches the published normal faults with steep bathymetry and is close to the International Seismological Center–Global Earthquake Model catalog locations of the 1918 mainshock and aftershocks. The ROV observations further show fresh vertical slickensides and rock exposure along the proposed fault trace. Hydrodynamic models from an Mw 7.2 earthquake rupture along the eastern wall of the rift faithfully reproduce the reported tsunami amplitudes, polarities, and arrival times. Our analysis emphasizes the value of close-up observations and physical samples to augment remote sensing data in natural hazard studies.

Revisiting the depth distribution of seismicity before and after the 2004–2008 eruption of Mount St. Helens

Hypocenter estimation at active volcanoes improves our understanding of their magmatic systems and indicates changing conditions at depth for continuously monitored volcanoes. The most active volcano in the Cascades Range, Mount St. Helens, has a multi-decadal earthquake catalog and it shows an apparent change in the depth distribution of seismicity before and after the 2004–2008 dome-building eruption and unrest sequence. We use two new resources to evaluate the accuracy of hypocenters and consequently the change in depth distribution of seismicity before and after the 2004–2008 eruption. First, we deployed a dense array of 136 three-component nodal seismographs for one month in 2017, including sub-arrays on the newly extruded dome and crater floor. Second, for events recorded during this month, we located their hypocenters using a three-dimensional (3D) wavefront-tracking location solver and a recently developed tomography model derived from active and passive source data. The relocated hypocenters are generally shallower and more concentrated beneath the crater compared to their catalog locations. The mean hypocenter movement from catalog locations is 2.86 km, with an averaged depth shift of 2.53 km upward. Comparison between 2017 hypocenters located using all of the available phase picks and those located using only the catalog picks from the permanent network suggests the improved hypocenters mostly resulted from the location solver and the 3D velocity model, with smaller changes due to the dense three-component array. Applying the same hypocenter estimation method to phase picks for all events from 1997 to 2004 and 2008–2021, we found a concentration of seismicity between sea level and ~ 1 km above it before and after the 2004–2008 eruption. The new results suggest that the seismogenic structure in the shallow magmatic system quickly re-equilibrated to its earlier state after the dome-building eruption.

Sharing datasets of the COVID-19 epidemic in the Czech Republic.

At the time of the COVID-19 pandemic, providing access to data (properly optimised regarding personal data protection) plays a crucial role in providing the general public and media with up-to-date information. Open datasets also represent one of the means for evaluation of the pandemic on a global level. The primary aim of this paper is to describe the methodological and technical framework for publishing datasets describing characteristics related to the COVID-19 epidemic in the Czech Republic (epidemiology, hospital-based care, vaccination), including the use of these datasets in practice. Practical aspects and experience with data sharing are discussed. As a reaction to the epidemic situation, a new portal COVID-19: Current Situation in the Czech Republic (https://onemocneni-aktualne.mzcr.cz/covid-19) was developed and launched in March 2020 to provide a fully-fledged and trustworthy source of information for the public and media. The portal also contains a section for the publication of (i) public open datasets available for download in CSV and JSON formats and (ii) authorised-access-only section where the authorised persons can (through an online generated token) safely visualise or download regional datasets with aggregated data at the level of the individual municipalities and regions. The data are also provided to the local open data catalogue (covering only open data on healthcare, provided by the Ministry of Health) and to the National Catalogue of Open Data (covering all open data sets, provided by various authorities/publishers, and harversting all data from local catalogues). The datasets have been published in various authentication regimes and widely used by general public, scientists, public authorities and decision-makers. The total number of API calls since its launch in March 2020 to 15 December 2020 exceeded 13 million. The datasets have been adopted as an official and guaranteed source for outputs of third parties, including public authorities, non-governmental organisations, scientists and online news portals. Datasets currently published as open data meet the 3-star open data requirements, which makes them machine-readable and facilitates their further usage without restrictions. This is essential for making the data more easily understandable and usable for data consumers. In conjunction with the strategy of the MH in the field of data opening, additional datasets meeting the already implemented standards will be also released, both on COVID-19 related and unrelated topics.

Using InSAR for evaluating the accuracy of locations and focal mechanism solutions of local earthquake catalogues

SUMMARYEarthquake source parameters play a fundamental role in evaluating seismic hazard. In many countries, the relatively low accuracy of the earthquake source parameters owing to sparse seismic monitoring networks prevents accurate seismic hazard evaluation. Interferometric Synthetic Aperture Radar (InSAR) is a useful tool for accurate fault parameter determination of shallow inland earthquakes. We compared the fault parameters (location and rupture geometry) derived from InSAR with those derived from local and global seismic data to assess the credibility of the earthquake catalogues. We set our targets to Iran and Japan, where seismic networks are relatively sparse and dense, respectively, and analysed a total of 10 shallow inland earthquakes. To compare the fault parameters for each studied earthquake, we first created interferograms using InSAR data from multiple satellites and conducted fault model inversions assuming uniform slip on a rectangular finite fault. For the studied Iranian earthquakes, the epicentres of the United States Geological Survey (USGS) catalogue were more consistent with the InSAR-derived fault model compared to those of the local catalogue of the Iranian Seismological Center (IRSC). For the studied Japanese earthquakes, the epicentres of the Japan Meteorological Agency (JMA) catalogue were more consistent with the InSAR-derived fault model compared to those of the USGS. Assuming that the accuracy of the USGS locations is comparable for the two countries, the JMA catalogue has a higher accuracy than the IRSC catalogue. The difference in the accuracy for the two local catalogues can be explained by the larger azimuthal gaps of the IRSC seismic network. We also showed that the IRSC- and JMA-derived centroids were more consistent with the InSAR-derived fault model compared to those of the Global Centroid Moment Tensor (GCMT) catalogue. The focal mechanism solutions derived from InSAR and seismic CMT solutions were significantly different, highlighting the difficulties in determining the focal mechanism parameters from seismic data, even when the seismic station coverage is dense. As InSAR data can be easily accessed, this study presents a cost-effective method to assess and improve the accuracy of the local earthquake catalogues anywhere in the world.

Building Precise Local Submarine Earthquake Catalogs via a Deep-Learning-Empowered Workflow and its Application to the Challenger Deep

Submarine active faults and earthquakes, which contain crucial information to seafloor tectonics and submarine geohazards, can be effectively characterized by precise submarine earthquake catalogs. However, the precise and rapid building of submarine earthquake catalogs is challenging due to the following facts: (i) intense noise in ocean seismic data; (ii) the sparse seismic network; (iii) the lack of historical near-field observations. In this paper, we built a deep-learning-based automatic workflow named ESPRH for automatically building submarine earthquake catalogs from continuous seismograms. The ESPRH workflow integrates Earthquake Transformer (EqT) and Siamese Earthquake Transformer (S-EqT) for initial earthquake detection and phase picking, PickNet for phase refinement, REAL for earthquake association and rough location, and HypoInverse, HypoDD for precise earthquake relocation. We apply ESPRH to the continuous data recorded by an array of 12 broadband Ocean Bottom Seismographs (OBS) near the Challenger Deep at the southern-most Mariana subduction zone from Dec. 2016 to Jun. 2017. In this study, we acquire a high-resolution local earthquakes catalog that provides new insights into the geometry of shallow fault zones. We report the active submarine faults by seismicity in Challenger Deep which is the deepest place on Earth. These faults are a significant reference for submarine geological hazards and evidence for serpentinization. Hence, the ESPRH is qualified to construct comprehensive local submarine earthquake catalogs automatically, rapidly, and precisely from raw OBS seismic data.

The unexpected Mayotte 2018–2020 seismic sequence: a reappraisal of the regional seismicity of the Comoros

The Mayotte seismic sequence that started on 10 May 2018, with a main shock of magnitude Mw 5.9 on May 15, followed by a major offshore volcanic activity, raises several questions of seismovolcanic hazards in the Comoros region. The unexpected size and duration of the crisis is an opportunity to reassess the distribution and magnitude of the seismicity near Mayotte Island, but also regionally. We present a comprehensive seismicity catalogue of the region including the Mozambique Channel, the Mozambique coast and Madagascar, based partly on previously published data in the region and partly on unpublished data from local catalogues for the Comoros and Madagascar. Our catalogue extends from 1900 onward with a completeness of magnitude 5.5 until 1980s and decreasing only recently to 4.5 after 2010. It comprises the events of magnitude Mlv ≥3.5 for the seismic sequence of Mayotte from May 2018 to October 2020 as the crisis is still ongoing. Present knowledge of the seismicity, largely partial in distribution and magnitude before 1980, makes the seismic sequence of 2018-2020 an exceptional and unprecedented seismo-volcanic event in the region. We discuss the distribution of seismicity in time and space within the context of the south eastward propagation of the East African rift system towards Madagascar.

Adding LCMPT Terms to Local Catalog Records for Notated Music for Voice and Piano

ABSTRACT Medium of performance is a valuable way to find music materials, but it is challenging to search by medium in library catalogs. Songs for specific voice types are especially difficult to look for using legacy metadata such as subject headings. This article describes a project to add terms from Library of Congress Medium of Performance Thesaurus for Music to records for scores for songs with piano in an academic library catalog. Appropriate terms are identified by examining subject headings and uncontrolled fields in the records. Adding these terms can enhance discovery and enables deeper analysis of the collection.

Designing Convolutional Neural Network Pipeline for Near‐Fault Earthquake Catalog Extension Using Single‐Station Waveforms

AbstractIn this study, we developed an end‐to‐end two‐stage pipeline using 1D convolutional neural networks (CNNs) to detect, localize, and characterize earthquakes from single‐station three‐component waveforms. We are presenting here the insights of what makes the difference in developing a deep learning algorithm by performing an extensive hyperparameter grid search for model training, tackling the question of the optimal number of classes, the importance of training data sets as well as the CNN architecture design in terms of optimal length of the CNN model. Moreover, our pipeline is robust and does not need any preprocessing of the seismograms (e.g., filtering) or any prior knowledge of the region. Training, validation, and evaluation of the CNN models is performed on data recorded at the AQU station placed in the city of L’Aquila in the Abruzzo region (Central Italy). Before MW 6.3 2009 L’Aquila earthquake that occurred near the city of L’Aquila the local catalog of events is sparse. Therefore, we provide a methodological pipeline on how one can extend near‐fault local catalog of earthquakes by applying our two‐stage pipeline on unseen continuous data. Our results show that we are able to design a CNN model that is detecting the earthquake events among random noise waveforms with 97% accuracy (first stage: detection). Additionally, we are able to determine the events that are close to the station (<10 km) with a 94% accuracy as well as identify their belonging to four magnitude classes with a 68% accuracy (second stage: characterization).

Foreshocks of the 2018 ML 4.0 Shimian Earthquake in the Anninghe Fault and Its Implications for Earthquake Nucleation

AbstractForeshock activity sometimes precedes large earthquakes, but how foreshocks relate to mainshock nucleation is still unclear with limited case studies existing. One way to further the understanding of the foreshock occurrence mechanism is to maximize the resolution of the foreshock characteristics by waveform-based earthquake detection and location. Here, we apply the match and locate method to scan continuous waveforms 30 days before and 44 days after the 2018 ML 4.0 Shimian earthquake in Sichuan, China, and obtain approximately three times more events than reported in a local catalog. The augmented seismicity suggests the existence of a blind small strike-slip fault deep in the east of the Anninghe fault. Forty-one foreshocks of magnitude ranging from ML−0.7 to 3.4 occurred within 4 hr before the mainshock and did not show an accelerating pattern leading up to the mainshock. Focal mechanisms are consistent between the mainshock and foreshocks, implying that the mainshock and foreshock hypocenters are located on the same fault plane. The high-precision relative locations reveal that most of the foreshocks rupture adjacent source patches along the fault plane, with little or partial overlap, which is consistent with cascade stress triggering from foreshocks to foreshocks to the mainshock. Our research is one of the few to focus on the foreshock sequence of moderate mainshocks and provides a new case for studying the mechanism of foreshocks of intraplate earthquakes with a low incidence of foreshocks.

Remote triggering in Iran: large peak dynamic stress is not the main driver of triggering

SUMMARYThe study of the dynamic triggering of earthquakes and tremors during large earthquakes at faraway distances is an active area of research. This type of remote dynamic triggering is often found in subduction zones. The Iranian plateau is part of the Alpine–Himalayan orogenic system and hosts different collision styles of deformation and significant strike-slip faults. Using 13 yr (26 December 2004–8 September 2017) of continuous data of Iranian National Seismic Network (INSN) and some dense temporary networks, for the first time we carried a systematic study of dynamic triggering in Iran during 47 recent large earthquakes with magnitude and depth ranges of 6.4–9.1 and 8–90 km, respectively. We explored the local catalogue of 124 805 events with a magnitude of completeness (Mc) of 1.8 for the study of dynamic triggering but did not find any convincing evidence of dynamic triggering from the catalogue. The waveform data of 24 hr duration around the main events were analysed to find possible dynamic triggering through manual analysis of the waveform, STA/LTA, and beta statistics and found the triggering. We found dynamic triggering in Iran during Sumatra, 26 December 2004, Mw 9.1; Tohoku-Oki, 11 March 2011, Mw 9.1; Indian Ocean, 11 April 2012, Mw8.6 and Baluchistan, 24 September 2013 earthquakes and also possible triggering during Sumatra, 12 September 2007, Mw8.5. Only ∼10 per cent of the analysed earthquakes produced dynamic triggering. The triggering initiates during the passage of high amplitude Love waves and continues through the passage of the Rayleigh waves. We found north, central and eastern regions are more probable for triggering than Zagros and Makran regions. The instances of triggering were not restricted to only a small region, but instead, occurred at multiple locations. We find the onset of tremor correlates with very small stress changes, on the order of 1 kPA. However, the amplitude of the dynamic stresses is not a sufficient condition since some of the areas with considerably larger dynamic stresses are not triggered any seismicity in the region. The backazimuth angle of ∼50° and ∼120° seems to play an important role in the triggering. Teleseismic waves most probable for triggering local earthquakes within NW and central Iran include incoming surface waves with an incident angle of ∼60°–90° with respect to the local fault fabric.

O ESTADO DO PIAUÍ NA EXPOSIÇÃO NACIONAL DE 1908

No início do século XX, as exposições foram percebidas como importantes instrumentos de modernização nacional, bem como de identificação dos recursos naturais do país, a fim de apontar suas possíveis possibilidades de uso. As elites políticas, econômicas e intelectuais piauienses passaram a defender o comparecimento do Piauí nas mostras expositivas, acreditando que traria inúmeros benefícios para a região, tais como investimentos de capitais estrangeiros e melhoramentos nas suas indústrias econômicas. Dessa forma, a proposta deste artigo é descrever e analisar a participação do Piauí na Exposição Nacional de 1908, realizada em comemoração ao primeiro centenário da abertura dos portos às nações amigas. A partir de periódicos locais, mensagens governamentais e catálogos dos produtos expostos, percebemos que a exposição foi oportuna para divulgação das potencialidades econômicas do estado que, desde a segunda metade do século XIX, se via na fronteira do progresso e reclamava maior atenção das autoridades governamentais. Palavras-chave: Piauí. Exposição. Integração.

A Novel Inertial-Aided Star Pattern Matching Method for Distributed Multiple FoVs

An aerospace vehicle in high-speed flight involves distributed multiple fields of view (FoVs) of a star sensor, and the maneuvering of the vehicle requires inertial-aided star pattern matching. Accordingly, an inertial-aided star pattern matching method for distributed multiple FoVs is proposed. First, the observation and fusion principles of distributed multiple FoVs are illustrated. Then, an inertial-aided star pattern matching scheme is designed based on the space-time distribution of the line-of sight (LoS) vector and inertial measurement information. Next, an LoS vector estimation method assisted by inertial information and the dynamic establishment of a distributed local catalog are proposed. Finally, in a simulation, the dynamic establishment of the part catalog improves the efficiency of star pattern matching by reducing the catalog scale, and the usability of inertial-aided star pattern matching is analyzed for different gyro and accelerometer precisions.