Multipath delay characteristics in mountainous terrain at 900 MHz

2003 ◽  
Author(s):  
P.F. Driessen
Keyword(s):  
Mountainous Terrain ◽  
Multipath Delay

scholarly journals Land-Use Improvements in the Weather Research and Forecasting Model over Complex Mountainous Terrain and Comparison of Different Grid Sizes

2021 ◽  
Author(s):  
Alessio Golzio ◽  
Silvia Ferrarese ◽  
Claudio Cassardo ◽  
Gugliemina Adele Diolaiuti ◽  
Manuela Pelfini
Keyword(s):  
Boundary Layer ◽  
Land Use ◽  
Land Cover ◽  
Mixing Layer ◽  
Local Area ◽  
Heat Fluxes ◽  
Weather Research And Forecasting ◽  
Forecasting Model ◽  
Mountainous Terrain ◽  
Weather Research

AbstractWeather forecasts over mountainous terrain are challenging due to the complex topography that is necessarily smoothed by actual local-area models. As complex mountainous territories represent 20% of the Earth’s surface, accurate forecasts and the numerical resolution of the interaction between the surface and the atmospheric boundary layer are crucial. We present an assessment of the Weather Research and Forecasting model with two different grid spacings (1 km and 0.5 km), using two topography datasets (NASA Shuttle Radar Topography Mission and Global Multi-resolution Terrain Elevation Data 2010, digital elevation models) and four land-cover-description datasets (Corine Land Cover, U.S. Geological Survey land-use, MODIS30 and MODIS15, Moderate Resolution Imaging Spectroradiometer land-use). We investigate the Ortles Cevadale region in the Rhaetian Alps (central Italian Alps), focusing on the upper Forni Glacier proglacial area, where a micrometeorological station operated from 28 August to 11 September 2017. The simulation outputs are compared with observations at this micrometeorological station and four other weather stations distributed around the Forni Glacier with respect to the latent heat, sensible heat and ground heat fluxes, mixing-layer height, soil moisture, 2-m air temperature, and 10-m wind speed. The different model runs make it possible to isolate the contributions of land use, topography, grid spacing, and boundary-layer parametrizations. Among the considered factors, land use proves to have the most significant impact on results.

scholarly journals Severity-Mapped Vibrotactile Cues to Support Interruption Management with Weather Messaging in the General Aviation Cockpit

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 341
Author(s):  
Carolina Rodriguez-Paras ◽  
Johnathan T. McKenzie ◽  
Pasakorn Choterungruengkorn ◽  
Thomas K. Ferris
Keyword(s):  
Situation Awareness ◽  
Failure Modes ◽  
General Aviation ◽  
Flight Training ◽  
Mountainous Terrain ◽  
Task Management ◽  
Training Device ◽  
Cognitive Demands ◽  
Weather Information ◽  
Interruption Management

Despite the increasing availability of technologies that provide access to aviation weather information in the cockpit, weather remains a prominent contributor to general aviation (GA) accidents. Pilots fail to detect the presence of new weather information, misinterpret it, or otherwise fail to act appropriately on it. When cognitive demands imposed by concurrent flight tasks are high, the risks increase for each of these failure modes. Previous research shows how introducing vibrotactile cues can help ease or redistribute some of these demands, but there is untapped potential in exploring how vibratory cues can facilitate “interruption management”, i.e., fitting the processing of available weather information into flight task workflow. In the current study, GA pilots flew a mountainous terrain scenario in a flight training device while receiving, processing, and acting on various weather information messages that were displayed visually, in graphical and text formats, on an experimental weather display. Half of the participants additionally received vibrotactile cues via a connected smartwatch with patterns that conveyed the “severity” of the message, allowing pilots to make informed decisions about when to fully attend to and process the message. Results indicate that weather messages were acknowledged more often and faster when accompanied by the vibrotactile cues, but the time after acknowledgment to fully process the messages was not significantly affected by vibrotactile cuing, nor was overall situation awareness. These findings illustrate that severity-encoded vibrotactile cues can support pilot awareness of updated weather as well as task management in processing weather messages while managing concurrent flight demands.

scholarly journals Mountain definitions and their consequences

Alpine Botany ◽  
2021 ◽  
Author(s):  
Christian Körner ◽  
Davnah Urbach ◽  
Jens Paulsen
Keyword(s):  
Species Richness ◽  
Population Density ◽  
Climatic Change ◽  
Plant Species ◽  
Human Population ◽  
Short Communication ◽  
Plant Species Richness ◽  
Mountainous Terrain ◽  
Human Population Density

AbstractMountains are rugged structures in the landscape that are difficult to delineate. Given that they host an overproportional fraction of biodiversity of high ecological and conservational value, conventions on what is mountainous and what not are in need. This short communication aims at explaining the differences among various popular mountain definitions. Defining mountainous terrain is key for global assessments of plant species richness in mountains and their likely responses to climatic change, as well as for assessing the human population density in and around mountainous terrain.

A Hazard and Risk Management System for Large Rock Slope Hazards Affecting Pipelines in Mountainous Terrain

2002 ◽  
Author(s):  
Michael Porter ◽  
Alex Baumgard ◽  
K. Wayne Savigny
Keyword(s):  
Risk Management ◽  
Rock Slope ◽  
Management Program ◽  
South American ◽  
Mountainous Terrain ◽  
Hazard Exposure ◽  
Access Road ◽  
Hazard And Risk ◽  
The Right ◽  
Hazard Rating

Pipelines and other linear facilities that traverse mountainous terrain may be subject to rock fall and rock slide hazards. A system is required to determine which sites pose the greatest hazard to the facility. Once sites are ranked according to hazard exposure, a risk management program involving inspection, monitoring, contingency planning and/or mitigation can be implemented in a systematic and defensible manner. A hazard rating methodology was developed to identify and characterize rock slope hazards above a South American Concentrate Pipeline, and to provide a relative ranking of hazard exposure for the pipeline, an access road and operational personnel. The rating methodology incorporates the geometry of the right-of-way, estimated pipe depth, staff and vehicle occupancy time, failure mechanism and magnitude, and the annual probability of hazard occurrence. This information is used in a risk-based framework to assign relative hazard ratings within rock slope sections of relatively uniform hazard exposure. This paper outlines a general framework for natural hazard and risk management along linear facilities, describes the rock slope hazard rating methodology, and illustrates how the system was applied along a South American Concentrate Pipeline.

scholarly journals High-Resolution Observations of Transport and Exchange Processes in Mountainous Terrain

Atmosphere ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 457 ◽  
Author(s):  
Stefan Emeis ◽  
Norbert Kalthoff ◽  
Bianca Adler ◽  
Eric Pardyjak ◽  
Alexandre Paci ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Mountainous Terrain ◽  
Full Spectrum ◽  
Spatiotemporal Information ◽  
Exchange Processes ◽  
Atmospheric Dynamic ◽  
In Situ Observations ◽  
Measurement Strategies ◽  
Mesoscale Processes

Mountainous areas require appropriate measurement strategies to cover the full spectrum of details concerning the energy exchange at the Earth’s surface and to capture the spatiotemporal distribution of atmospheric dynamic and thermodynamic fields over them. This includes the range from turbulence to mesoscale processes and its interaction. The surface energy balance needs appropriate measurement strategies as well. In this paper, we present an overview of important experiments performed over mountainous terrain and summarize the available techniques for flow and energy measurements in complex terrain. The description includes ground-based and airborne in situ observations as well as ground-based and airborne remote sensing (passive and active) observations. Emphasis is placed on systems which retrieve spatiotemporal information on mesoscale and smaller scales, fitting mountainous terrain research needs. Finally, we conclude with a short list summarizing challenges and gaps one faces when dealing with measurements over complex terrain.

Sign in / Sign up

Export Citation Format

Share Document