Multiple solutions for asteroid orbits: Computational procedure and applications

We describe the Multiple Solutions Method, a one-dimensional sampling of the six-dimensional orbital confidence region that is widely applicable in the field of asteroid orbit determination. In many situations there is one predominant direction of uncertainty in an orbit determination or orbital prediction, i.e., a ``weak'' direction. The idea is to record Multiple Solutions by following this, typically curved, weak direction, or Line Of Variations (LOV). In this paper we describe the method and give new insights into the mathematics behind this tool. We pay particular attention to the problem of how to ensure that the coordinate systems are properly scaled so that the weak direction really reflects the intrinsic direction of greatest uncertainty. We also describe how the multiple solutions can be used even in the absence of a nominal orbit solution, which substantially broadens the realm of applications. There are numerous applications for multiple solutions; we discuss a few problems in asteroid orbit determination and prediction where we have had good success with the method. In particular, we show that multiple solutions can be used effectively for potential impact monitoring, preliminary orbit determination, asteroid identification, and for the recovery of lost asteroids

Orbit determination of space objects based on sparse optical data

While building up a catalog of Earth orbiting objects, if the available optical observations are sparse, not deliberate follow ups of specific objects, no orbit determination is possible without previous correlation of observations obtained at different times. This correlation step is the most computationally intensive, and becomes more and more difficult as the number of objects to be discovered increases. In this paper we tested two different algorithms (and the related prototype software) recently developed to solve the correlation problem for objects in geostationary orbit (GEO), including the accurate orbit determination by full least squares solutions with all six orbital elements. Because of the presence in the GEO region of a significant subpopulation of high area to mass objects, strongly affected by non-gravitational perturbations, it was actually necessary to solve also for dynamical parameters describing these effects, that is to fit between 6 and 8 free parameters for each orbit. The validation was based upon a set of real data, acquired from the ESA Space Debris Telescope (ESASDT) at the Teide observatory (Canary Islands). We proved that it is possible to assemble a set of sparse observations into a set of objects with orbits, starting from a sparse time distribution of observations, which would be compatible with a survey capable of covering the region of interest in the sky just once per night. This could result in a significant reduction of the requirements for a future telescope network, with respect to what would have been required with the previously known algorithm for correlation and orbit determination.Comment: 20 pages, 8 figure

Stature estimation for personal identification using mandibular morphometric parameters in Italian population: a preliminary report.

Stature is fundamental in personal identification for forensic and physical anthropologists. When a full skeleton is not available, stature can be estimated from incomplete human remains. It is also important to apply a method to estimate the stature based on the same specific population of the remains. For this purpose, we measured 4 distances between cephalometric landmarks of the mandible and the stature in 56 subjects (both males and females) from Caucasian Italian population. The correlation between these parameters appeared to be statistically significant, so that it was possible to establish a regression equation to estimate the stature from the mandible in this population

Implementing Geographical Information System to Provide Evident Support for Crime Analysis

AbstractGeographical Information System (GIS) is one of the aiding domains of technology where a number of applications are being deployed to assist people in understanding and visualizing data rather than having it in other complex forms. Implementing one of such kinds of technology for crime analysis will help people in knowing the crime rate of their place in comparison to other places and will also provide hand-in-hand support to the police for providing additional focus on those regions. Crimes are the concerning factors of every country for its political, economical and social development. Yet, the number of technologies available in detecting and reporting crimes are limited. A Geographical Information System(GIS) based application can be implemented that can be used and accessed by everyone to file the crimes happening in their locality and to know about other crimes. This paper deals about the GIS based tools and their functions in developing such an application. This application will provide evident support for the officials to monitor and to concentrate more on those localities reported as crime

Long-term impact risk for (101955) 1999 RQ36

The potentially hazardous asteroid (101955) 1999 RQ36 has the possibility of collision with the Earth in the latter half of the 22nd century, well beyond the traditional 100-year time horizon for routine impact monitoring. The probabilities accumulate to a total impact probability of approximately 10E-3, with a pair of closely related routes to impact in 2182 comprising more than half of the total. The analysis of impact possibilities so far in the future is strongly dependent on the action of the Yarkovsky effect, which raises new challenges in the careful assessment of longer term impact hazards. Even for asteroids with very precisely determined orbits, a future close approach to Earth can scatter the possible trajectories to the point that the problem becomes like that of a newly discovered asteroid with a weakly determined orbit. If the scattering takes place late enough so that the target plane uncertainty is dominated by Yarkovsky accelerations then the thermal properties of the asteroid,which are typically unknown, play a major role in the impact assessment. In contrast, if the strong planetary interaction takes place sooner, while the Yarkovsky dispersion is still relatively small compared to that derived from the measurements, then precise modeling of the nongravitational acceleration may be unnecessary.Comment: Reviewed figures and some text change

LIMIT ANALYSIS APPROACH FOR THE SEISMIC VULNERABILITY REDUCTION OF MASONRY TOWERS THROUGH STRENGTHENING WITH TRADITIONAL AND INNOVATIVE MATERIALS

The paper investigates the possibility and the effectiveness of reducing the seismic vulnerability of masonry towers by means of composite materials and traditional steel bands. Masonry towers are very widespread in Italy, both as bell towers for churches and defense towers in medieval cities and castles. Masonry material, presenting low mechanical properties, is not suitable to withstand significant tensile and compression stresses induced by earthquake loading. The slenderness of these structures is another factor that can reduce the bearing capacity when significant stresses are present in specific structural parts. The seismic vulnerability of masonry towers is very high, as a consequence of both poor material properties in tension and high compression levels at the base of the structure. Moreover, Italy is characterized by a high potential risk to be stricken by moderate/high seismic events, as experienced in the last decades. In such a situation, the seismic upgrading of masonry towers could appear rather important. Seismic upgrading by introducing both traditional steel bars and composite materials as strips or rebars is analyzed in detail for different towers. Based on some a priori assumed failure modes (one proposed by Heyman), simplified models from a limit analysis approach are here discussed and used to define the most suitable retrofitting solution. The retrofitting possibilities consist of: a) horizontal hooping rings; b) vertical pre-stressed tie rods; c) vertical composite strips. A simplified straightforward relationship is found between the retrofitting requirements and seismic hazard. The procedure is applied for a wide range of geometrical properties and appears to be fast and reliable

Molecular characterization of twenty seeded and seedless table grape cultivars (Vitis vinifera L.)

DNA and isoenzyme analyses were used to characterize 20 table grape cultivars including Moscato d'Amburgo, Italia, Sultanina, Bicane and some recently released new varieties. GPI and PGM isoenzyme systems were able to separate the cultivars into 9 groups whereas the 8 microsatellite loci that were analysed revealed a higher discriminating power. In fact, all the cultivars could be distinguished by DNA profiles except Sugraone from its sport Sugrafive. Parentage analysis confirmed that the cultivar Italia was obtained from the crossing Bicane x Moscato d'Amburgo. A difference was observed at one microsatellite locus between Sultanina and the published data for Thompson Seedless, considered to be its synonym. The different microsatellite loci were evaluated for their informativeness

Genetic analysis of non-recessive factors of resistance to diazinon in the SKA strain of the housefly (Musca domestica L)

RESP-560