Ionospheric refraction effects on orbit determination using the orbit determination error analysis system

The influence of ionospheric refraction on orbit determination was studied through the use of the Orbit Determination Error Analysis System (ODEAS). The results of a study of the orbital state estimate errors due to the ionospheric refraction corrections, particularly for measurements involving spacecraft-to-spacecraft tracking links, are presented. In current operational practice at the Goddard Space Flight Center (GSFC) Flight Dynamics Facility (FDF), the ionospheric refraction effects on the tracking measurements are modeled in the Goddard Trajectory Determination System (GTDS) using the Bent ionospheric model. While GTDS has the capability of incorporating the ionospheric refraction effects for measurements involving ground-to-spacecraft tracking links, such as those generated by the Ground Spaceflight Tracking and Data Network (GSTDN), it does not have the capability to incorporate the refraction effects for spacecraft-to-spacecraft tracking links for measurements generated by the Tracking and Data Relay Satellite System (TDRSS). The lack of this particular capability in GTDS raised some concern about the achievable accuracy of the estimated orbit for certain classes of spacecraft missions that require high-precision orbits. Using an enhanced research version of GTDS, some efforts have already been made to assess the importance of the spacecraft-to-spacecraft ionospheric refraction corrections in an orbit determination process. While these studies were performed using simulated data or real tracking data in definitive orbit determination modes, the study results presented here were obtained by means of covariance analysis simulating the weighted least-squares method used in orbit determination

TERRESTRIAL LASER SCANNER FOR MONITORING THE DEFORMATIONS AND THE DAMAGES OF BUILDINGS

scanner provides the ability to detect the geometric 3D model of a building without any physical contact with the structure. Knowledge of the 3D model will give the opportunity to study the deformation and quantify the damages. Three case studies are presented relating to damaged and/or unsafe buildings: Sivillier Castle (Villasor - Sardinia- Italy), the Bell Tower of Mores (Sardinia-Italy) and industrial building (Cagliari - Italy). The first two cases concern buildings of historical and architectural importance that present a state of compromised conservation; the last, an industrial building compromised by fire. In all cases, a laser scanner survey was carried out that not only provided valuable information but also highlighted structural metric deformation and degradation

Study of geopotential error models used in orbit determination error analysis

The uncertainty in the geopotential model is currently one of the major error sources in the orbit determination of low-altitude Earth-orbiting spacecraft. The results of an investigation of different geopotential error models and modeling approaches currently used for operational orbit error analysis support at the Goddard Space Flight Center (GSFC) are presented, with emphasis placed on sequential orbit error analysis using a Kalman filtering algorithm. Several geopotential models, known as the Goddard Earth Models (GEMs), were developed and used at GSFC for orbit determination. The errors in the geopotential models arise from the truncation errors that result from the omission of higher order terms (omission errors) and the errors in the spherical harmonic coefficients themselves (commission errors). At GSFC, two error modeling approaches were operationally used to analyze the effects of geopotential uncertainties on the accuracy of spacecraft orbit determination - the lumped error modeling and uncorrelated error modeling. The lumped error modeling approach computes the orbit determination errors on the basis of either the calibrated standard deviations of a geopotential model's coefficients or the weighted difference between two independently derived geopotential models. The uncorrelated error modeling approach treats the errors in the individual spherical harmonic components as uncorrelated error sources and computes the aggregate effect using a combination of individual coefficient effects. This study assesses the reasonableness of the two error modeling approaches in terms of global error distribution characteristics and orbit error analysis results. Specifically, this study presents the global distribution of geopotential acceleration errors for several gravity error models and assesses the orbit determination errors resulting from these error models for three types of spacecraft - the Gamma Ray Observatory, the Ocean Topography Experiment, and the Cosmic Background Explorer

Coping with cancer: A prospective psycho-social analysis of cancer patients and their non-medical caregivers (cg) – A goim study

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Photo-oxidative and soil burial degradation of irrigation tubes based on biodegradable polymer blends

Irrigation tubes based on biodegradable polymers were prepared via an extrusion-drawing process by Irritec and compared to conventional pipes made of high-density polyethylene (HDPE). A commercial polylactide/poly (butyleneadipate-co-butyleneterephthalate) (PLA/PBAT) blend (Bio-Flex®) and Mater-Bi® were used. The polymers were characterized from rheological and mechanical points of view. Irrigation pipes were subjected to photoaging with continued exposure to UV radiation up to 22 days. The degradability in the soil of irrigation tube samples was studied. The influence of temperature and UV irradiation on soil burial degradation was investigated. A soil burial degradation test was carried out at 30 °C and 50 °C for up to 70 days. The degree of degradation was evaluated from the weight loss percentage. The degradation rate of irrigation tube samples based on Mater-Bi® was higher at 30 °C and was stimulated after 14 days of UV irradiation. Higher temperatures or UV aging encouraged the disintegration in soil of Bio-Flex®-based irrigation tubes. Furthermore, tube samples, before and after UV and soil burial degradation, were analyzed by Attenuated Total Reflection-Fourier Transform Infra-Red (ATR-FTIR) spectroscop

Biochemical and nutritional traits of sea bass (Dicentrachus labrax) from different rearing systems.

Farmed European sea bass (Dicentrarchus labrax), sampled from three different culture systems (intensive in sea-cages, intensive in land-based basins and extensive in lagoon and storage basins of salt-work), of the Northern, Central and Southern Italy, were analyzed with the aim to employ nutritional trait to describe and to distinguish the "origin" of the product. Lipid and fatty acid profile, strongly affected by the feeding history and environmental factors, responsible of the nu- tritional and perceived quality of fish product, are proposed as marker of origin

Comparison of ERBS orbit determination accuracy using batch least-squares and sequential methods

The Flight Dynamics Div. (FDD) at NASA-Goddard commissioned a study to develop the Real Time Orbit Determination/Enhanced (RTOD/E) system as a prototype system for sequential orbit determination of spacecraft on a DOS based personal computer (PC). An overview is presented of RTOD/E capabilities and the results are presented of a study to compare the orbit determination accuracy for a Tracking and Data Relay Satellite System (TDRSS) user spacecraft obtained using RTOS/E on a PC with the accuracy of an established batch least squares system, the Goddard Trajectory Determination System (GTDS), operating on a mainframe computer. RTOD/E was used to perform sequential orbit determination for the Earth Radiation Budget Satellite (ERBS), and the Goddard Trajectory Determination System (GTDS) was used to perform the batch least squares orbit determination. The estimated ERBS ephemerides were obtained for the Aug. 16 to 22, 1989, timeframe, during which intensive TDRSS tracking data for ERBS were available. Independent assessments were made to examine the consistencies of results obtained by the batch and sequential methods. Comparisons were made between the forward filtered RTOD/E orbit solutions and definitive GTDS orbit solutions for ERBS; the solution differences were less than 40 meters after the filter had reached steady state

Filter parameter tuning analysis for operational orbit determination support

The use of an extended Kalman filter (EKF) for operational orbit determination support is being considered by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD). To support that investigation, analysis was performed to determine how an EKF can be tuned for operational support of a set of earth-orbiting spacecraft. The objectives of this analysis were to design and test a general purpose scheme for filter tuning, evaluate the solution accuracies, and develop practical methods to test the consistency of the EKF solutions in an operational environment. The filter was found to be easily tuned to produce estimates that were consistent, agreed with results from batch estimation, and compared well among the common parameters estimated for several spacecraft. The analysis indicates that there is not a sharply defined 'best' tunable parameter set, especially when considering only the position estimates over the data arc. The comparison of the EKF estimates for the user spacecraft showed that the filter is capable of high-accuracy results and can easily meet the current accuracy requirements for the spacecraft included in the investigation. The conclusion is that the EKF is a viable option for FDD operational support

NEPA (netupitant/palonosetron) for the antiemetic prophylaxis of nausea and vomiting induced by chemotherapy (CINV) with Folfirinox and Folfoxiri even during the COVID-19 pandemic: A real-life study

OBJECTIVE: The outbreak of coronavirus disease 2019 (COVID-19) has affected the treatment of cancer patients, with particular regard to the management of both chemotherapy and side effects. Chemotherapy-induced nausea and vomiting (CINV) are amongst the most troublesome side effects that impair patients’ adherence to treatments and their quality of life (QoL). NEPA (Akynzeo®), is an oral fixed-dose combination of netupitant [a neurokinin-1 receptor antagonist (NK1RA), 300 mg] and palonosetron [(5-hydroxytryptamine (serotonin or 5HT) type3 receptor antagonist (5HT3RA), 0.5 mg] which has been shown to be effective in preventing CINV. PATIENTS AND METHODS: This prospective study started before the outbreak of COVID-19 and was carried out during the pandemic period. The aim was to evaluate the efficacy and safety of a single oral dose NEPA plus 12 mg of dexamethasone (DEX) in patients treated with Folfoxiri plus Bevacizumab and Folfirinox. The patients were diagnosed with advanced colorectal cancer (CRC) or advanced pancreatic ductal adenocarcinoma (PDAC). They were divided into two groups: naïve patients and patients previously treated with serotonin receptor antagonists (5HT3-RA) and neurokin-1 receptor antagonists (NK1-RA). RESULTS: During the overall phase, the complete response (CR) rate was 96.8% in naïve patients treated with Folfoxiri plus Bevacizumab, and 94.6% in patients treated with Folfirinox. During the acute and delayed phases, the CR rate was 92.8% and 94.2%, with Folfoxiri and Bevacizumab, as well as 96.2% and 94.6%, with Folfirinox. There was no adequate control of CINV events in patients on antiemetic prophylaxis with 5HT3-RA or NK1-RA associated with cortisone. During the overall phase, the CR rate was 74.6% with Folfoxiri plus Bevacizumab and 75.8% with Folfirinox. During the acute and delayed phases, the CR rate was 72.5% and 74.8% with Folfoxiri plus Bevacizumab, as well as 75.2% and 74.6% with Folfirinox. CONCLUSIONS: This study has shown the therapeutic benefits of NEPA in the management and prophylaxis of CINV events, both in naive patients and patients previously treated with 5HT3-RA and NK1-RA. In addition, NEPA has been shown to be safe, both before and during the COVID-19 pandemic