BDS GNSS for Earth Observation

For millennia, human communities have wondered about the possibility of observing phenomena in their surroundings, and in particular those affecting the Earth on which they live. More generally, it can be conceptually defined as Earth observation (EO) and is the collection of information about the biological, chemical and physical systems of planet Earth. It can be undertaken through sensors in direct contact with the ground or airborne platforms (such as weather balloons and stations) or remote-sensing technologies. However, the definition of EO has only become significant in the last 50 years, since it has been possible to send artificial satellites out of Earth’s orbit. Referring strictly to civil applications, satellites of this type were initially designed to provide satellite images; later, their purpose expanded to include the study of information on land characteristics, growing vegetation, crops, and environmental pollution. The data collected are used for several purposes, including the identification of natural resources and the production of accurate cartography. Satellite observations can cover the land, the atmosphere, and the oceans. Remote-sensing satellites may be equipped with passive instrumentation such as infrared or cameras for imaging the visible or active instrumentation such as radar. Generally, such satellites are non-geostationary satellites, i.e., they move at a certain speed along orbits inclined with respect to the Earth’s equatorial plane, often in polar orbit, at low or medium altitude, Low Earth Orbit (LEO) and Medium Earth Orbit (MEO), thus covering the entire Earth’s surface in a certain scan time (properly called ’temporal resolution’), i.e., in a certain number of orbits around the Earth. The first remote-sensing satellites were the American NASA/USGS Landsat Program; subsequently, the European: ENVISAT (ENVironmental SATellite), ERS (European Remote-Sensing satellite), RapidEye, the French SPOT (Satellite Pour l’Observation de laTerre), and the Canadian RADARSAT satellites were launched. The IKONOS, QuickBird, and GeoEye-1 satellites were dedicated to cartography. The WorldView-1 and WorldView-2 satellites and the COSMO-SkyMed system are more recent. The latest generation are the low payloads called Small Satellites, e.g., the Chinese BuFeng-1 and Fengyun-3 series. Also, Global Navigation Satellite Systems (GNSSs) have captured the attention of researchers worldwide for a multitude of Earth monitoring and exploration applications. On the other hand, over the past 40 years, GNSSs have become an essential part of many human activities. As is widely noted, there are currently four fully operational GNSSs; two of these were developed for military purposes (American NAVstar GPS and Russian GLONASS), whilst two others were developed for civil purposes such as the Chinese BeiDou satellite navigation system (BDS) and the European Galileo. In addition, many other regional GNSSs, such as the South Korean Regional Positioning System (KPS), the Japanese quasi-zenital satellite system (QZSS), and the Indian Regional Navigation Satellite System (IRNSS/NavIC), will become available in the next few years, which will have enormous potential for scientific applications and geomatics professionals. In addition to their traditional role of providing global positioning, navigation, and timing (PNT) information, GNSS navigation signals are now being used in new and innovative ways. Across the globe, new fields of scientific study are opening up to examine how signals can provide information about the characteristics of the atmosphere and even the surfaces from which they are reflected before being collected by a receiver. EO researchers monitor global environmental systems using in situ and remote monitoring tools. Their findings provide tools to support decision makers in various areas of interest, from security to the natural environment. GNSS signals are considered an important new source of information because they are a free, real-time, and globally available resource for the EO community

Rilievo integrato presso il Borgo Schirò (PA)

Il lavoro qui presentato consiste in un rilievo integrato (Topografico/GPS statico/NRTK/Laser Scanner) di un piccolo contesto extraurbano siciliano, Borgo Schirò, noto per le vicende storiche che portarono alla sua costruzione a seguito dell’emanazione della legge n.1 del 2 gennaio 1940, per il superamento del latifondo. Data la natura varia degli elementi da rilevare (edifici, arredo urbano, strade) sono state adottate tecniche di acquisizione diversificate per ognuno di essi, le quali, in forma integrata, hanno permesso un utile confronto finale degli elaborati prodotti, offrendo la possibilità di effettuare analisi qualitative altamente accurate su singoli casi strutturali ed elevati gradi di dettaglio nei casi architettonici focalizzati. Le tempistiche notevolmente contenute e l’esiguità del numero degli operatori necessari alle operazioni di acquisizione ed elaborazione dei dati, rendono soddisfacenti gli esiti raggiunti e chiaramente proficua l’integrazione delle metodologie di rilievo adottate.The work here shown consists of an integrated survey (Topographic/static GPS/NRTK/Laser Scanning) of a small Sicilian extraurban context, Borgo Schirò, known for the historical events that led to its construction, following the issuance of the law n. 1 of January 2nd 1940, for the elimination of the latifondium. Given the different nature of the elements to be surveyed (buildings, urban elements, roads) different techniques of metric data acquisition were used for each of them. The integration of all of them, allowed a useful comparison of the final products, offering the possibility of making highly accurate qualitative analysis on the individual structural cases and a high level of detail in the architectural cases focused. The reduced timing and the very small number of operators needed for data acquisition and processing, make the achieved outcomes satisfactory and the integration of survey methods adopted clearly successful

Il GIS per il monitoraggio e la gestione del ciclo integrato dei rifiuti in Sicilia

Il problema dei rifiuti è una questione di grande attualità e di rilevanza nazionale: ogni giorno i servizi d’informazione trattano della cosiddetta “emergenza rifiuti” anche se, visto il perdurare e il rinnovarsi di tante “emergenze”, si dovrebbe parlare di ordinaria situazione di inefficienza del sistema di smaltimento. In realtà, la situazione della “gestione dei rifiuti” risulta essere assai più complessa di quanto emerga dai media nazionali. È ancora più arduo scoprire le “falle” del sistema e ricercare le motivazioni di una tale inefficienza, poiché, nella stessa penisola, l’applicazione della normativa di settore è avvenuta in maniera differente e disomogenea. Per questo arduo compito vengono sicuramente a supporto delle decisioni i sistemi informativi territoriali come strumento importantissimo per il monitoraggio e la programmazione di un problema vastissimo e pluridisciplinare come quello della gestione del ciclo integrato dei rifiuti. L’attuazione di corrette pratiche di gestione dei rifiuti ha ripercussione in molti settori della vita civile di una Comunità interessando oltre al territorio e l’ambiente, la sanità, le infrastrutture, e non ultimo, l’ordine pubblico. Questo studio nasce dall’esigenza reale degli uffici del Dipartimento dell’Acqua e dei Rifiuti della Regione Siciliana di avere una visone d’insieme sulla situazione attuale delle Società d’Ambito (ATO) e una proiezione dei possibili scenari in vista dell’attuazione della legge che istituisce nell’isola le Società per la Regolamentazione dei Rifiuti (SRR). Partendo dall’acquisizione dei dati regionali, attività alquanto laboriosa e problematica sia per l’eterogeneità delle fonti sia soprattutto per la mancanza di una standardizzazione dei dati, e dalla loro validazione è stata creata una banca dati dettagliata sulla quantità di rifiuti prodotti nei singoli Comuni, la percentuale di raccolta differenziata, il costo del servizio complessivo e per abitante, il personale impiegato nei vari servizi ed il relativo costo, le infrastrutture presenti nel territorio (discariche, impianti di compost, centri comunali di raccolta, isole ecologiche), il costo del conferimento in discarica, l’analisi economica con i dati aggregati dei debiti e crediti delle ATO siciliane. Sono state anche effettuate delle simulazioni sullo stato futuro delle discariche a intervalli semestrali in relazione ai dati di produzione dei singoli comuni. Una volta strutturato il Database, sono state svolte parecchie analisi spaziali con strumenti GIS che hanno fatto emergere tutte quelle criticità, che sono alla base dell’enorme indebitamento nella gestione dei rifiuti, come le differenti tariffe di conferimento, le distanze dai centri di conferimento, l’inadeguatezza delle discariche, i costi del personale, ma hanno anche fatto emergere quello che sarà il futuro della gestione dei rifiuti in Sicilia con le costituende SRR, evidenziando immediatamente la loro distribuzione poco omogenea rispetto ai Comuni assegnati, e confrontando i dati di popolazione, la produzione di rifiuti e il numero dei Comuni appartenenti alle varie SRR, si nota una evidente sproporzione nella distribuzione dei carichi. Questo lavoro, attraverso uno studio approfondito delle dinamiche di conferimento dei rifiuti in discarica, vuole offrire una possibile soluzione al monitoraggio del ciclo dei rifiuti e al problema delle grandi distanze che i Comuni percorrono per lo smaltimento. Si è analizzata l’incidenza del trasporto sui costi di gestione e dell’impatto sull’ambiente, in relazione agli inquinanti immessi in atmosfera. La sola introduzione del correttivo di livellamento delle tariffe di conferimento nelle varie discariche, dovrebbe eliminare quasi totalmente il problema

Optimizing the Sampling Area across an Old-Growth Forest via UAV-Borne Laser Scanning, GNSS, and Radial Surveying

Aboveground biomass, volume, and basal area are among the most important structural attributes in forestry. Direct measurements are cost-intensive and time-consuming, especially for old-growth forests exhibiting a complex structure over a rugged topography. We defined a methodology to optimize the plot size and the (total) sampling area, allowing for structural attributes with a tolerable error to be estimated. The plot size was assessed by analyzing the semivariogram of a CHM model derived via UAV laser scanning, while the sampling area was based on the calculation of the absolute relative error as a function of allometric relationships. The allometric relationships allowed the structural attributes from trees’ height to be derived. The validation was based on the positioning of a number of trees via total station and GNSS surveys. Since high trees occlude the GNSS signal transmission, a strategy to facilitate the positioning was to fix the solution using the GLONASS constellation alone (showing the highest visibility during the survey), and then using the GPS constellation to increase the position accuracy (up to PDOP~5−10). The tree heights estimated via UAV laser scanning were strongly correlated (r2 = 0.98, RMSE = 2.80 m) with those measured in situ. Assuming a maximum absolute relative error in the estimation of the structural attribute (20% within this work), the proposed methodology allowed the portion of the forest surface (≤60%) to be sampled to be quantified to obtain a low average error in the calculation of the above mentioned structural attributes (≤13

Performance Assessment of PPP Surveys with Open Source Software Using the GNSS GPS\u2013GLONASS\u2013Galileo Constellations

In this work, the performance of the multi-GNSS (Global Navigation Satellite System) Precise Point Positioning (PPP) technique, in static mode, is analyzed. Specifically, GPS (Global Positioning System), GLONASS, and Galileo systems are considered, and quantifying the Galileo contribution is one of the main objectives. The open source software RTKLib is adopted to process the data, with precise satellite orbits and clocks from CNES (Centre National d\u2019Etudes Spatiales) and CLS (Collecte Localisation Satellites) analysis centers for International GNSS Service (IGS). The Iono-free model is used to correct ionospheric errors, the GOT-4.7 model is used to correct tidal effects, and Differential Code Biases (DCB) are taken from the Deutsche Forschungsanstalt f\ufcr Luftund Raumfahrt (DLR) center. Two different tropospheric models are tested: Saastamoinen and Estimate ZTD (Zenith Troposhperic Delay). For the proposed study, a dataset of 31 days from a permanent GNSS station, placed in Palermo (Italy), and a dataset of 10 days from a static geodetic receiver, placed nearby the station, have been collected and processed by the most used open source software in the geomatic community. The considered GNSS configurations are seven: GPS only, GLONASS only, Galileo only, GPS+GLONASS, GPS+Galileo, GLONASS+Galileo, and GPS+GLONASS+Galileo. The results show significant performance improvement of the GNSS combinations with respect to single GNSS cases

Analisi cartografica e GPS di punti fiduciali

Scopo di questo lavoro \ue8 l'analisi cartografica di punti fiduciali (P.F.), attraverso la comparazione delle coordinate di un dataset di sessanta vertici presenti nella citt\ue0 di Palermo. Come supporto cartografico di riferimento \ue8 stato preso la carta ufficiale del Comune di Palermo, che \ue8 in formato digitale ed \ue8 stata recentemente realizzata con metodo aerofotogrammetrico (2007). Le coordinate dei punti fiduciali sono state confrontate con differenti supporti cartografici e web: mappe catastali georiferite (nel sistema nazionale Gauss-Boaga), mappe derivanti dagli applicativi web Google Earth e fiduciali.it. Oltre ai confronti con i supporti cartografici dei P.F., \ue8 stata effettuata una vasta campagna di rilievi GPS/GNNS in modalita NRTK con stazionamenti fuoricentro, legati alla particolare natura dei punti rilevati (in maggioranza spigoli di fabbricati); questo metodo, ampiamente utilizzato in letteratura, ha richiesto un lavoro molto oneroso poich\ue9 \ue8 stato necessario rilevare direttamente i P.F. L'analisi sviluppata dimostra l'adeguatezza del rilievo NRTK alla determinazione delle coordinate dei P.F., mentre i risultati provenienti dagli applicativi Google Earth e fiduciali.it sono in forte discontinuit\ue0 rispetto alla Cartografia Tecnica Comunale

Performance assessment of PPP surveys with open source software using the GNSS GPS-GLONASS-Galileo constellations

In this work, the performance of the multi-GNSS (Global Navigation Satellite System) Precise Point Positioning (PPP) technique, in static mode, is analyzed. Specifically, GPS (Global Positioning System), GLONASS, and Galileo systems are considered, and quantifying the Galileo contribution is one of the main objectives. The open source software RTKLib is adopted to process the data, with precise satellite orbits and clocks from CNES (Centre National d'Etudes Spatiales) and CLS (Collecte Localisation Satellites) analysis centers for International GNSS Service (IGS). The Iono-free model is used to correct ionospheric errors, the GOT-4.7 model is used to correct tidal effects, and Differential Code Biases (DCB) are taken from the Deutsche Forschungsanstalt für Luftund Raumfahrt (DLR) center. Two different tropospheric models are tested: Saastamoinen and Estimate ZTD (Zenith Troposhperic Delay). For the proposed study, a dataset of 31 days from a permanent GNSS station, placed in Palermo (Italy), and a dataset of 10 days from a static geodetic receiver, placed nearby the station, have been collected and processed by the most used open source software in the geomatic community. The considered GNSS configurations are seven: GPS only, GLONASS only, Galileo only, GPS+GLONASS, GPS+Galileo, GLONASS+Galileo, and GPS+GLONASS+Galileo. The results show significant performance improvement of the GNSS combinations with respect to single GNSS cases

Oil quality and sugar content of peanuts (Arachis hypogaea) grown in Argentina : their relationship with climatic variables and seed yield

The ratio of oleic to linoleic acids (O/L) and the tocopherol content are important features in determining peanut (Arachis hypogaea) seed shelf life. Soluble carbohydrates are known to be important precursors in roasted peanut flavor. The chemical qualities of Argentine grain are different from those of other countries, but no previous studies that associate grain quality and environmental parameters have been performed. Relationships were determined between O/L, tocopherol and sugar contents, and variations in temperature and rainfall during the grain filling period of Florman INTA peanuts. Dry seed yield was used as another explanatory variable. Multiple regression procedure gave mean temperature (positive coefficient) and total precipitation (negative coefficient) as the explanatory variables for variations in O/L. Total precipitation and dry seed yield (both negative coefficients) were found to be predictor variables for tocopherol and sugar contents. Total precipitation was an explanatory variable included in all of the linear regression models obtained in this study.Fil: Casini, Cristiano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Dardanelli, Julio Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Martinez, Maria Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Nassetta, Mirtha. Agencia Córdoba Ciencia. Unidad Ceprocor; ArgentinaFil: Borgogno, Carmen S. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Balzarini, Mónica. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentin

A Kalman filter single point positioning for maritime applications using a smartphone

Different positioning techniques have been largely adopted for maritime applications that require high accuracy kinematic positioning. The main objective of the paper is the performance assessment of a Single Point Positioning algorithm (SPP), with a Kalman filter (KF) estimator, adapted for maritime applications. The KF has been chosen as estimation technique due to the ability to consider both the state vector dynamic and the measurements. Particularly, in order to compute an accurate vertical component of the position, suitable for maritime applications, the KF settings have been modified by tuning the covariance matrix of the process noise. The algorithm is developed in Matlab environment and tested using multi-GNSS single-frequency raw data, collected by a smartphone located on board a moving ship. The algorithm performance evaluation is carried out in position domain and the results show an enhancement of meter order on vertical component compared to the classical SPP based on Least Square estimation technique. In addition, different GNSSs configurations are considered to verify the benefits of their integration in terms of accuracy, solution availability and geometry

SARS-CoV-2 infection among hospitalised pregnant women and impact of different viral strains on COVID-19 severity in Italy: a national prospective population-based cohort study

OBJECTIVE: The primary aim of this article was to describe SARS-CoV-2 infection among pregnant women during the wild-type and Alpha-variant periods in Italy. The secondary aim was to compare the impact of the virus variants on the severity of maternal and perinatal outcomes. DESIGN: National population-based prospective cohort study. SETTING: A total of 315 Italian maternity hospitals. SAMPLE: A cohort of 3306 women with SARS-CoV-2 infection confirmed within 7 days of hospital admission. METHODS: Cases were prospectively reported by trained clinicians for each participating maternity unit. Data were described by univariate and multivariate analyses. MAIN OUTCOME MEASURES: COVID-19 pneumonia, ventilatory support, intensive care unit (ICU) admission, mode of delivery, preterm birth, stillbirth, and maternal and neonatal mortality. RESULTS: We found that 64.3% of the cohort was asymptomatic, 12.8% developed COVID-19 pneumonia and 3.3% required ventilatory support and/or ICU admission. Maternal age of 30-34 years (OR 1.43, 95% CI 1.09-1.87) and ≥35 years (OR 1.62, 95% CI 1.23-2.13), citizenship of countries with high migration pressure (OR 1.75, 95% CI 1.36-2.25), previous comorbidities (OR 1.49, 95% CI 1.13-1.98) and obesity (OR 1.72, 95% CI 1.29-2.27) were all associated with a higher occurrence of pneumonia. The preterm birth rate was 11.1%. In comparison with the pre-pandemic period, stillbirths and maternal and neonatal deaths remained stable. The need for ventilatory support and/or ICU admission among women with pneumonia increased during the Alpha-variant period compared with the wild-type period (OR 3.24, 95% CI 1.99-5.28). CONCLUSIONS: Our results are consistent with a low risk of severe COVID-19 disease among pregnant women and with rare adverse perinatal outcomes. During the Alpha-variant period there was a significant increase of severe COVID-19 illness. Further research is needed to describe the impact of different SARS-CoV-2 viral strains on maternal and perinatal outcomes