712 research outputs found

    Orthorectification of prisma images

    Get PDF
    Orthorectification is one of the most important satellite imagery pre-processing applications, as it allows to use data, for example, in geographic information systems, making the most of high or medium resolution. Since May 2020, PRISMA (PRecursore IperSpettrale della Missione Applicativa) mission, a project of the Italian Space Agency, has become fully accessible to the community. PRISMA satellite integrates a hyperspectral sensor and a medium-resolution panchromatic sensor. The products are currently available with a declared geolocation accuracy of 200 m, which ASI plans to increase to half pixel in the near future by introducing geometric treatment of the images with Ground Control Points (GCPs). However, the orthorectification of PRISMA images is not a proven and validated procedure, due to the uncertainty of satellite orbital and internal orientation data provided in the metadata file and to the lack of contributions on the subject in literature. In the present work, our contribution on possible strategies for the geometric treatment of PRISMA images is shown. The results obtained by applying the Rational Polynomial Coefficients (RPC) provided with some panchromatic images show coarse rototranslations. For this reason, a procedure was developed to restore conformity between RPCs and the panchromatic image. The best results in terms of accuracy were obtained with the rational polynomials using RPF approach, achieving residuals calculated on the Check Points (CP) in the order of one pixel, better than those supposed by ASI using GCPs. Probably even better results could be obtained with more rigorous information on RPCs or orbital and orientation parameters

    Studio delle possibilitĂ  di utilizzo della costellazione Glonass nel suo stato

    Get PDF
    GLONASS (Global Navigation Satellite System) is a global position satellite system realized by ex- Urss at the same time with the United State’s one. The first launch of satellites went back to 12th October 1982, they completed constellation with 24 satellites in 1997. In the years Russia didn’t have economic force to maintain active the entire constellation. But in 2002 GLONASS relaunching started, that provides 18 satellites before 2007, and it will reach 24 satellites before 2010. The program provides the launch of three or two rockets a year, each one will bring to space two or three satellite. At present (15th September 2006) there are 15 operative GLONASS satellites. The aim of this work is to show the potentiality of the jointed use of GPS and GLONASS satellites by performing an adequate subdivision of the observations collected during a survey in the area of Rome using TOPCON receivers able to acquire data coming from both constellations

    First considerations on post processing kinematic GNSS data during a geophysical oceanographic cruise

    Get PDF
    Differential GNSS positioning on vessels is of considerable interest in various fields of application as navigation aids, precision positioning for geophysical surveys or sampling purposes especially when high resolution bathymetric surveys are conducted. However ship positioning must be considered a kinematic survey with all the associated problems. The possibility of using high-precision differential GNSS receivers in navigation is of increasing interest, also due to the very recent availability of low-cost differential receivers that may soon replace classic navigation ones based on the less accurate point positioning technique. The availability of greater plano-altimetric accuracy, however, requires an increasingly better understanding of planimetric and altimetric reference systems. In particular, the results allow preliminary considerations on the congruence between terrestrial reference systems (which the GNSS survey can easily refer to) and marine reference systems (connected to National Tidegauge Network). In spite of the fluctuations due to the physiological continuous variation of the ship's attitude, GNSS plot faithfully followed the trend of the tidal variations and highlighted the shifts between GNSS plot and the tide gauges due to the different materialization of the relative reference systems

    TTF-1/p63-positive poorly differentiated NSCLC: A histogenetic hypothesis from the basal reserve cell of the terminal respiratory unit

    Get PDF
    TTF-1 is expressed in the alveolar epithelium and in the basal cells of distal terminal bronchioles. It is considered the most sensitive and specific marker to define the adenocarcinoma arising from the terminal respiratory unit (TRU). TTF-1, CK7, CK5/6, p63 and p40 are useful for typifying the majority of non-small-cell lung cancers, with TTF and CK7 being typically expressed in adenocarcinomas and the latter three being expressed in squamous cell carcinoma. As tumors with coexpression of both TTF-1 and p63 in the same cells are rare, we describe different cases that coexpress them, suggesting a histogenetic hypothesis of their origin. We report 10 cases of poorly differentiated non-small-cell lung carcinoma (PD-NSCLC). Immunohistochemistry was performed by using TTF-1, p63, p40 (∆Np63), CK5/6 and CK7. EGFR and BRAF gene mutational analysis was performed by using real-time PCR. All the cases showed coexpression of p63 and TTF-1. Six of them showing CK7+ and CK5/6− immunostaining were diagnosed as “TTF-1+ p63+ adenocarcinoma”. The other cases of PD-NSCLC, despite the positivity for CK5/6, were diagnosed as “adenocarcinoma, solid variant”, in keeping with the presence of TTF-1 expression and p40 negativity. A “wild type” genotype of EGFR was evidenced in all cases. TTF1 stained positively the alveolar epithelium and the basal reserve cells of TRU, with the latter also being positive for p63. The coexpression of p63 and TTF-1 could suggest the origin from the basal reserve cells of TRU and represent the capability to differentiate towards different histogenetic lines. More aggressive clinical and morphological features could characterize these “basal-type tumors” like those in the better known “basal-like” cancer of the breast

    The Role of PARP Inhibitors in the Ovarian Cancer Microenvironment: Moving Forward From Synthetic Lethality

    Get PDF
    PARP inhibitors (PARPi) have shown promising clinical results and have revolutionized the landscape of ovarian cancer management in the last few years. While the core mechanism of action of these drugs has been largely analyzed, the interaction between PARP inhibitors and the microenvironment has been scarcely researched so far. Recent data shows a variety of mechanism through which PARPi might influence the tumor microenvironment and especially the immune system response, that might even partly be the reason behind PARPi efficacy. One of many pathways that are affected is the cGAS-cGAMP-STING; the upregulation of STING (stimulator of interferon genes), produces more Interferon ϒ and pro inflammatory cytokines, thus increasing intratumoral CD4+ and CD8+ T cells. Upregulation of immune checkpoints such as PD1-PDL1 has also been observed. Another interesting mechanism of interaction between PARPi and microenvironment is the ability of PARPi to kill hypoxic cells, as these cells show an intrinsic reduction in the expression and function of the proteins involved in HR. This process has been defined “contextual synthetic lethality”. Despite ovarian cancer having always been considered a poor responder to immune therapy, data is now shedding a new light on the matter. First, OC is much more heterogenous than previously thought, therefore it is fundamental to select predictive biomarkers for target therapies. While single agent therapies have not yielded significant results on the long term, influencing the immune system and the tumor microenvironment via the concomitant use of PARPi and other target therapies might be a more successful approach

    Control of near-infrared supercontinuum bandwidth by adjusting pump pulse duration

    Get PDF
    We experimentally and numerically investigated the impact of input pump pulse duration on the near-infrared bandwidth of supercontinuum generation in a photonic crystal fiber. We continuously stretched the temporal duration of the input pump laser (centered at 1030 nm) pulses from 500 fs up to 10 ps, while keeping fixed the pump peak power. We observed that the long-wavelength edge of the supercontinuum spectrum is increased by 200 nm as the pump pulse duration grows from 500 fs to 10 ps. We provide a quantitative fit of the experimental results by means of numerical simulations. Moreover, we have explained the observed spectral broadening enhancement induced by pump pulse energy by developing an approximate yet fully analytical model for soliton energy exchange through a series of collisions in the presence of stimulated Raman scattering
    • 

    corecore