Uav Photogrammetry: Block Triangulation Comparisons

UAVs systems represent a flexible technology able to collect a big amount of high resolution information, both for metric and interpretation uses. In the frame of experimental tests carried out at Dept. ICA of Politecnico di Milano to validate vector-sensor systems and to assess metric accuracies of images acquired by UAVs, a block of photos taken by a fixed wing system is triangulated with several software. The test field is a rural area included in an Italian Park ("Parco Adda Nord"), useful to study flight and imagery performances on buildings, roads, cultivated and uncultivated vegetation. The UAV SenseFly, equipped with a camera Canon Ixus 220HS, flew autonomously over the area at a height of 130 m yielding a block of 49 images divided in 5 strips. Sixteen pre-signalized Ground Control Points, surveyed in the area through GPS (NRTK survey), allowed the referencing of the block and accuracy analyses. Approximate values for exterior orientation parameters (positions and attitudes) were recorded by the flight control system. The block was processed with several software: Erdas-LPS, EyeDEA (Univ. of Parma), Agisoft Photoscan, Pix4UAV, in assisted or automatic way. Results comparisons are given in terms of differences among digital surface models, differences in orientation parameters and accuracies, when available. Moreover, image and ground point coordinates obtained by the various software were independently used as initial values in a comparative adjustment made by scientific in-house software, which can apply constraints to evaluate the effectiveness of different methods of point extraction and accuracies on ground check points

In situ cleaning of diagnostic first mirrors: An experimental comparison between plasma and laser cleaning in ITER-relevant conditions

This paper presents an experimental comparison between the plasma cleaning and the laser cleaning techniques of diagnostic first mirrors (FMs). The re-deposition of contaminants sputtered from a tokamak first wall onto FMs could dramatically decrease their reflectance in an unacceptable way for the proper functioning of plasma diagnostic systems. Therefore, suitable in situ cleaning solutions will be required to recover the FMs reflectance in ITER. Currently, plasma cleaning and laser cleaning are considered the most promising solutions. In this work, a set of ITER-like rhodium mirrors contaminated with materials tailored to reproduce tokamak redeposits is employed to experimentally compare plasma and laser cleaning against different criteria (reflectance recovery, mirror integrity, time requirement). We show that the two techniques present different complementary features that can be exploited for the cleaning of ITER FMs. In particular, plasma cleaning ensures an excellent reflectance recovery in the case of compact contaminants, while laser cleaning is faster, gentler, and more effective in the case of porous contaminant. In addition, we demonstrate the potential benefits of a synergistic solution which combines plasma and laser cleaning to exploit the best features of each technique

Síndrome purpúrico-papular em "luvas e meias" por parvovírus B19: relato de caso

We present a case of papular-purpuric "gloves and socks" syndrome (PPGSS) in an adult male with acute parvovirus B19 infection. The patient displayed the classical features of fever, oral lesions, and purpura on hands and feet, but the purpuric lesions on the feet evolved to superficial skin necrosis, a feature not previously described in this syndrome. We believe this is the first reported case of PPGSS occurring in Brazil.Um caso de síndrome purpúrico-papular em "luvas e meias" devido à infecção aguda por parvovírus B19 é descrito em um homem adulto que, além das manifestações clássicas de febre, lesões orais e púrpura em mãos e pés, evoluiu com icterícia e necrose cutânea superficial dos pés, características até então não descritas nesta síndrome. Acreditamos tratar-se do primeiro caso descrito no Brasil

Wave energy farm design in real wave climates: the Italian offshore

publisher: Elsevier articletitle: Wave energy farm design in real wave climates: the Italian offshore journaltitle: Energy articlelink: http://dx.doi.org/10.1016/j.energy.2017.01.094 content_type: article copyright: © 2017 Elsevier Ltd. All rights reserved