scholarly journals A HIGH-FIDELITY ARTIFICIAL AIRPORT ENVIRONMENT FOR SESAR APOC VALIDATION EXPERIMENTS

2017 ◽  
Vol 8 (1) ◽  
pp. 31-50 ◽  
Author(s):  
Florian Piekert ◽  
Nils Carstengerdes ◽  
Sebastian Schier ◽  
Reiner Suikat ◽  
Alan Marsden
Keyword(s):  
Situation Awareness ◽  
Weather Conditions ◽  
High Fidelity ◽  
Airport Management ◽  
Traffic System ◽  
Adverse Weather Conditions ◽  
Artificial Environment ◽  
Wide Range ◽  
Adverse Weather ◽  
Before And After

Europe’s SESAR Program develops a wide range of solutions to increase the performance of the Air Traffic System. At airport level, the Airport Operations Center (APOC) is expected to provide the most benefit in adverse weather conditions, being the ultimate communication platform to pursue the Total Airport Management (TAM) Collaborative Decision Making Process. It will increase mutual and common situation awareness and allows the joint definition and implementation of the operational strategy. The assessment of APOC benefits in a live airport environment is rather limited and requires implementation and “right” weather and traffic situations. This work argues for validation trials in high fidelity artificial airport environments as a more reliable and less costly alternative which allows comparison between operations before and after implementation of new solutions. Based on requirements provided by SESAR concept documentation and from live operations this work presents an approach for such a high fidelity artificial environment.

scholarly journals A Review of Detection and Removal of Raindrops in Automotive Vision Systems

2021 ◽  
Vol 7 (3) ◽  
pp. 52
Author(s):  
Yazan Hamzeh ◽  
Samir A. Rawashdeh
Keyword(s):  
Detrimental Effect ◽  
Weather Conditions ◽  
Traffic Sign ◽  
Survey Paper ◽  
Sign Recognition ◽  
Adverse Weather Conditions ◽  
Wide Range ◽  
Adverse Weather ◽  
Protective Cover

Research on the effect of adverse weather conditions on the performance of vision-based algorithms for automotive tasks has had significant interest. It is generally accepted that adverse weather conditions reduce the quality of captured images and have a detrimental effect on the performance of algorithms that rely on these images. Rain is a common and significant source of image quality degradation. Adherent rain on a vehicle’s windshield in the camera’s field of view causes distortion that affects a wide range of essential automotive perception tasks, such as object recognition, traffic sign recognition, localization, mapping, and other advanced driver assist systems (ADAS) and self-driving features. As rain is a common occurrence and as these systems are safety-critical, algorithm reliability in the presence of rain and potential countermeasures must be well understood. This survey paper describes the main techniques for detecting and removing adherent raindrops from images that accumulate on the protective cover of cameras.

Effect of Stern Flaps on Powering Performance of the FFG-7 Class

1993 ◽  
Vol 30 (01) ◽  
pp. 39-50
Author(s):  
William L. Cave ◽  
Dominic S. Cusanelli
Keyword(s):  
Fuel Consumption ◽  
Weather Conditions ◽  
Full Scale ◽  
Wave System ◽  
Test Results ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Before And After ◽  
The Cost ◽  
Percent Decrease

The effect of a stern flap on the powering performance and annual fuel consumption of an FFG-7 Oliver Hazard Perry Class Guided Missile Frigate is presented. Analytical analysis using free surface potential flow theory was conducted to evaluate the flow on the afterbody of the ship. Model tests were conducted to determine the optimum geometrical characteristics of the stern flap. Based on the analytical and model test results, a stern flap was retrofitted to an FFG-7 Class frigate, and full-scale results on powering performance were collected. Results of model powering experiments showed that the flap, set at 10 deg trailing edge down, decreased the delivered power by 8.4 percent at 26 knots, and provided for a 3.8 percent decrease in annual fuel consumption. This decrease in annual fuel consumption places the payback period on the cost of the flap installation at only 10 months. The full-scale comparison of the flap's effectiveness was marred by adverse weather conditions and differences in the pre-and post-flap ship configurations. However, observations of the full-scale stern wave system, before and after the installation of the stern flap, lead the authors to conclude that the flap will produce a larger decrease in delivered power at full scale than shown by the model experiments.

scholarly journals BLIND CONTRAST ENHANCEMENT ASSESSMENT BY GRADIENT RATIOING AT VISIBLE EDGES

2011 ◽  
Vol 27 (2) ◽  
pp. 87 ◽  
Author(s):  
Nicolas Hautière ◽  
Jean-Philippe Tarel ◽  
Didier Aubert ◽  
Éric Dumont
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Image Quality Assessment ◽  
Weather Conditions ◽  
Reference Image ◽  
Tone Mapping ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Before And After ◽  
Visibility Enhancement

The contrast of outdoor images acquired under adverse weather conditions, especially foggy weather, is altered by the scattering of daylight by atmospheric particles. As a consequence, differentmethods have been designed to restore the contrast of these images. However, there is a lack of methodology to assess the performances of the methods or to rate them. Unlike image quality assessment or image restoration areas, there is no easy way to have a reference image, which makes the problem not straightforward to solve. In this paper, an approach is proposed which consists in computing the ratio between the gradient of the visible edges between the image before and after contrast restoration. In this way, an indicator of visibility enhancement is provided based on the concept of visibility level, commonly used in lighting engineering. Finally, the methodology is applied to contrast enhancement assessment and to the comparison of tone-mapping operators.

scholarly journals Key Features and Adverse Weather of the Named Subtropical Cyclones over the Southwestern South Atlantic Ocean

Atmosphere ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 6 ◽  
Author(s):  
Michelle Reboita ◽  
Rosmeri da Rocha ◽  
Débora Oliveira
Keyword(s):  
Atlantic Ocean ◽  
Vertical Wind Shear ◽  
Moisture Flux ◽  
Weather Conditions ◽  
South Atlantic ◽  
South Atlantic Ocean ◽  
Brazilian Coast ◽  
Adverse Weather Conditions ◽  
Wide Range ◽  
Adverse Weather

This work documents the main features of six subtropical cyclones occurred between the years 2010 and 2016 over the southwestern South Atlantic Ocean, near the Brazilian coast, which received names (with the exception of one) from the Brazilian Navy Hydrographic Center. The fine-resolution ERA5 reanalysis and rainfall estimates from the Tropical Rainfall Measuring Mission (TRMM) were used to describe the synoptic environment and the adverse weather conditions during the six events. The support of a small-amplitude trough at mid-levels or a cut-off low, weak vertical wind shear, and moisture flux convergence are the main features contributing to the subtropical cyclogenesis at the surface. On the other hand, sea surface temperature (SST) presents a secondary contribution since the cyclones develop over the ocean with a wide range of SST values (from 22.5 °C to 28.6 °C in the initial phase of cyclones). The six subtropical cyclones are less deep in the atmosphere column than the tropical ones and, unlike the extratropical cyclones, they have little or no westward tilt with an increase in height. The studied subtropical cyclones produced adverse weather conditions such as (a) strong winds (reaching 17 m·s−1 at 10 m high) for a long period occurring east/southeastward of the cyclone center, and (b) high amounts of rainfall along the southeastern coast of Brazil, where the accumulated rainfall varied between 170 to 350 mm, being in most cases higher than the monthly climatology. Over the continent, the Brazilian states of Rio de Janeiro and Espírito Santo were the most affected by the intense rainfall associated with the cyclones.

scholarly journals Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Weather Conditions ◽  
Hull Form ◽  
Best Available Technologies ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
New Type ◽  
Technological Challenge ◽  
And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

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