scholarly journals Accurate 3D fireball trajectory and orbit calculation using the 3D-FireTOC automatic Python code

Author(s):  
Eloy Peña-Asensio ◽  
Josep Maria Trigo-Rodríguez ◽  
Maria Gritsevich ◽  
Albert Rimola

Abstract The disruption of asteroids and comets produces cm-sized meteoroids that end up impacting the Earth’s atmosphere and producing bright fireballs that might have associated shock waves or, in geometrically-favorable occasions excavate craters that put them into unexpected hazardous scenarios. The astrometric reduction of meteors and fireballs to infer their atmospheric trajectories and heliocentric orbits involves a complex and tedious process that generally requires many manual tasks. To streamline the process, we present a software package called SPMN 3D Fireball Trajectory and Orbit Calculator (3D-FireTOC), an automatic Python code for detection, trajectory reconstruction of meteors, and heliocentric orbit computation from video recordings. The automatic 3D-FireTOC package comprises of a user interface and a graphic engine that generates a realistic 3D representation model, which allows users to easily check the geometric consistency of the results and facilitates scientiï¬c content production for dissemination. The software automatically detects meteors from digital systems, completes the astrometric measurements, performs photometry, computes the meteor atmospheric trajectory, calculates the velocity curve, and obtains the radiant and the heliocentric orbit, all in all quantifying the error measurements in each step. The software applies corrections such as light aberration, refraction, zenith attraction, diurnal aberration and atmospheric extinction. It also characterizes the atmospheric flight and consequently determines fireball fates by using the α − β criterion that analyses the ability of a fireball to penetrate deep into the atmosphere and produce meteorites. We demonstrate the performance of the software by analyzing two bright fireballs recorded by the Spanish Fireball and Meteorite Network (SPMN).

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
F. A. Abd El-Salam

The concept of solar sailing and its developing spacecraft is presented. The gravitational and solar radiation forces are considered. The effect of source of radiation pressure and the force due to coronal mass ejections and solar wind on the sailcraft configurations is modeled. Some analytical control laws with some mentioned input constraints for optimizing sailcraft dynamics in heliocentric orbit using lagrange’s planetary equations are obtained. Optimum force vector in a required direction is maximized by deriving optimal sail cone angle. Ignoring the absorbed and diffusely reflected parts of the radiation, some special cases are obtained. New control laws that maximize thrust to obtain certain required maximization in some particular orbital element are obtained.


Author(s):  
R. Ati Sukmawati ◽  
Mitra Pramita ◽  
Harja Santana Purba ◽  
Bekti Utami

The purpose of this study is to analyze student learning outcomes in the application of the blended cooperative learning model, and analyze students' perceptions about the application of the cooperative blended learning model. Quantitative and qualitative research methods were used together with 91 subjects as participants in Introduction to Digital Systems academic year 2018/2019. Data was collected by tests, questionnaires, observations and video recordings. The results showed that the student learning outcomes were in the sufficient category. Students showed a positive perception of the implementation of the blended cooperative learning model, but they still need more encouragement to be more independent in learning.


1966 ◽  
Vol 25 ◽  
pp. 363-371
Author(s):  
P. Sconzo

In this paper an orbit computation program for artificial satellites is presented. This program is operational and it has already been used to compute the orbits of several satellites.After an introductory discussion on the subject of artificial satellite orbit computations, the features of this program are thoroughly explained. In order to achieve the representation of the orbital elements over short intervals of time a drag-free perturbation theory coupled with a differential correction procedure is used, while the long range behavior is obtained empirically. The empirical treatment of the non-gravitational effects upon the satellite motion seems to be very satisfactory. Numerical analysis procedures supporting this treatment and experience gained in using our program are also objects of discussion.


Author(s):  
T. A. Dodson ◽  
E. Völkl ◽  
L. F. Allard ◽  
T. A. Nolan

The process of moving to a fully digital microscopy laboratory requires changes in instrumentation, computing hardware, computing software, data storage systems, and data networks, as well as in the operating procedures of each facility. Moving from analog to digital systems in the microscopy laboratory is similar to the instrumentation projects being undertaken in many scientific labs. A central problem of any of these projects is to create the best combination of hardware and software to effectively control the parameters of data collection and then to actually acquire data from the instrument. This problem is particularly acute for the microscopist who wishes to "digitize" the operation of a transmission or scanning electron microscope. Although the basic physics of each type of instrument and the type of data (images & spectra) generated by each are very similar, each manufacturer approaches automation differently. The communications interfaces vary as well as the command language used to control the instrument.


Author(s):  
Ashley Pozzolo Coote ◽  
Jane Pimentel

Purpose: Development of valid and reliable outcome tools to document social approaches to aphasia therapy and to determine best practice is imperative. The aim of this study is to determine whether the Conversational Interaction Coding Form (CICF; Pimentel & Algeo, 2009) can be applied reliably to the natural conversation of individuals with aphasia in a group setting. Method: Eleven graduate students participated in this study. During a 90-minute training session, participants reviewed and practiced coding with the CICF. Then participants independently completed the CICF using video recordings of individuals with non-fluent and fluent aphasia participating in an aphasia group. Interobserver reliability was computed using matrices representative of the point-to-point agreement or disagreement between each participant's coding and the authors' coding for each measure. Interobserver reliability was defined as 80% or better agreement for each measure. Results: On the whole, the CICF was not applied reliably to the natural conversation of individuals with aphasia in a group setting. Conclusion: In an extensive review of the turns that had high disagreement across participants, the poor reliability was attributed to inadequate rules and definitions and inexperienced coders. Further research is needed to improve the reliability of this potentially useful clinical tool.


Author(s):  
N. K. Jha ◽  
S. Gupta
Keyword(s):  

1991 ◽  
Vol 65 (04) ◽  
pp. 425-431 ◽  
Author(s):  
F Stockmans ◽  
H Deckmyn ◽  
J Gruwez ◽  
J Vermylen ◽  
R Acland

SummaryA new in vivo method to study the size and dynamics of a growing mural thrombus was set up in the rat femoral vein. The method uses a standardized crush injury to induce a thrombus, and a newly developed transilluminator combined with digital analysis of video recordings. Thrombi in this model formed rapidly, reaching a maximum size 391 ± 35 sec following injury, after which they degraded with a half-life of 197 ± 31 sec. Histological examination indicated that the thrombi consisted mainly of platelets. The quantitative nature of the transillumination technique was demonstrated by simultaneous measurement of the incorporation of 111In labeled platelets into the thrombus. Thrombus formation, studied at 30 min interval in both femoral veins, showed satisfactory reproducibility overall and within a given animalWith this method we were able to induce a thrombus using a clinically relevant injury and to monitor continuously and reproducibly the kinetics of thrombus formation in a vessel of clinically and surgically relevant size


2005 ◽  
Vol 6 (2) ◽  
pp. 65 ◽  
Author(s):  
Marc Gerdisch ◽  
Thomas Hinkamp ◽  
Stephen D. Ainsworth

<P>Background: Use of the interrupted coronary anastomosis has largely been abandoned in favor of the more rapid continuous suturing technique. The Coalescent U-CLIP anastomotic device allows the surgeon to create an interrupted distal anastomosis in the same amount of time that it would take to create a continuous anastomosis. This acute bovine study examined the effect of the anastomotic technique on blood flow and vessel wall function. </P><P>Methods: End-to-side coronary anastomoses were created in an open chest bovine model using the left and right internal thoracic arteries and the left anterior descending coronary artery. All other variables except suturing technique were carefully controlled. In each animal, one anastomosis was completed using a continuous suturing technique and the other was performed in an interrupted fashion using the Coalescent U-CLIP anastomotic device. Volumetric flow curves through each graft were analyzed using key indicators of anastomotic quality, and anastomotic compliance was evaluated using intravascular ultrasound. Luminal castings were created of each vessel to examine the interior surface of each anastomosis for constrictions and deformities. </P><P>Results: The interrupted anastomoses created with the Coalescent U-CLIP anastomotic device showed significant differences with respect to anastomotic compliance, pulsatility index, peak flow, and percentage of diastolic flow. The cross-sectional area and degree of luminal deformity were also different for the two suturing techniques. </P><P>Conclusions: In this acute bovine model, interrupted coronary anastomoses demonstrated superior geometric consistency and greater physiologic compliance than did continuously sutured anastomoses. The interrupted anastomosis also caused fewer disturbances to the flow waveform, behaving similarly to a normal vessel wall. The combination of these effects may influence both acute and long-term patency of the coronary bypass grafts.</P>


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