scholarly journals Signal propagation modeling in complex, three-dimensional environments

2021 ◽  
Author(s):  
D. Wilson ◽  
Daniel Breton ◽  
Lauren Waldrop ◽  
Danney Glaser ◽  
Ross Alter ◽  
...  
Keyword(s):  
High Frequency ◽  
Complex Terrain ◽  
Three Dimensional ◽  
Weather Forecast ◽  
Signal Propagation ◽  
Environmental Modeling ◽  
Environmental Data ◽  
Very High Frequency ◽  
Intelligence System ◽  
Propagation Modeling

The Signal Physics Representation in Uncertain and Complex Environments (SPRUCE) work unit, part of the U.S. Army Engineer Research and Development Center (ERDC) Army Terrestrial-Environmental Modeling and Intelligence System (ARTEMIS) work package, focused on the creation of a suite of three-dimensional (3D) signal and sensor performance modeling capabilities that realistically capture propagation physics in urban, mountainous, forested, and other complex terrain environments. This report describes many of the developed technical capabilities. Particular highlights are (1) creation of a Java environmental data abstraction layer for 3D representation of the atmosphere and inhomogeneous terrain that ingests data from many common weather forecast models and terrain data formats, (2) extensions to the Environmental Awareness for Sensor and Emitter Employment (EASEE) software to enable 3D signal propagation modeling, (3) modeling of transmitter and receiver directivity functions in 3D including rotations of the transmitter and receiver platforms, (4) an Extensible Markup Language/JavaScript Object Notation (XML/JSON) interface to facilitate deployment of web services, (5) signal feature definitions and other support for infrasound modeling and for radio-frequency (RF) modeling in the very high frequency (VHF), ultra-high frequency (UHF), and super-high frequency (SHF) frequency ranges, and (6) probabilistic calculations for line-of-sight in complex terrain and vegetation.

scholarly journals The Three-Dimensional Locating of VHF Broadband Lightning Interferometers

Atmosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 317 ◽  
Author(s):  
Hengyi Liu ◽  
Shi Qiu ◽  
Wansheng Dong
Keyword(s):  
Time Resolution ◽  
High Frequency ◽  
Three Dimensional ◽  
High Time Resolution ◽  
Very High Frequency ◽  
Time Difference Of Arrival ◽  
Lightning Discharges ◽  
Total Lightning ◽  
Locating Information ◽  
Very High

VHF (Very High Frequency) lightning interferometers can locate and observe lightning discharges with a high time resolution. Especially the appearance of continuous interferometers makes the 2-D location of interferometers further improve in time resolution and completeness. However, there is uncertainty in the conclusion obtained by simply analyzing the 2-D locating information. Without the support of other 3-D total lightning locating networks, the 2-station interferometer becomes an option to obtain 3-D information. This paper introduces a 3-D lightning location method of a 2-station broadband interferometer, which uses the theodolite wind measurement method for reference, and gives the simulation results of the location accuracy. Finally, using the multi-baseline continuous 2-D locating method and the 3-D locating method, the locating results of one intra-cloud flash and the statistical results of the initiation heights of 61 cloud-to-ground flashes and 80 intra-cloud flashes are given. The results show that the two-station interferometer has high observation accuracy on both sides of the connection between the two sites. The locating accuracy will deteriorate as the distance between the radiation source and the two stations increases or the height decreases. The actual locating results are similar to those of the existing VHF TDOA (Time Difference of Arrival) lightning locating network.

scholarly journals Epithelial Thickness After Hyperopic LASIK: Three-Dimensional Display with Artemis Very High-Frequency Digital Ultrasound

2009 ◽  
Vol 26 (8) ◽  
pp. 555-564 ◽  
Author(s):  
Dan Z. Reinstein ◽  
Timothy J. Archer ◽  
Marine Gobbe ◽  
Ronald H. Silverman ◽  
D. Jackson Coleman
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Very High Frequency ◽  
Epithelial Thickness ◽  
Three Dimensional Display ◽  
Very High

An efficient, low profile, electrically small, three-dimensional, very high frequency magnetic EZ antenna

2010 ◽  
Vol 96 (10) ◽  
pp. 104102 ◽  
Author(s):  
Chia-Ching Lin ◽  
Richard W. Ziolkowski ◽  
Jean A. Nielsen ◽  
Minas H. Tanielian ◽  
Christopher L. Holloway
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Very High Frequency ◽  
Low Profile ◽  
Very High

scholarly journals Epithelial, Stromal, and Total Corneal Thickness in Keratoconus: Three-Dimensional Display with Artemis Very-High Frequency Digital Ultrasound

2010 ◽  
Vol 26 (4) ◽  
pp. 259-271 ◽  
Author(s):  
Dan Z. Reinstein ◽  
Marine Gobbe ◽  
Timothy J. Archer ◽  
Ronald H. Silverman ◽  
D. Jackson Coleman
Keyword(s):  
High Frequency ◽  
Corneal Thickness ◽  
Three Dimensional ◽  
Very High Frequency ◽  
Three Dimensional Display ◽  
Very High

scholarly journals Epithelial Thickness in the Normal Cornea: Three-dimensional Display With Artemis Very High-frequency Digital Ultrasound

2008 ◽  
Vol 24 (6) ◽  
pp. 571-581 ◽  
Author(s):  
Dan Z Reinstein ◽  
Marine Gobbe ◽  
Timothy J Archer ◽  
Ronald H Silverman ◽  
Jackson Coleman
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Very High Frequency ◽  
Epithelial Thickness ◽  
Three Dimensional Display ◽  
Very High
Sign in / Sign up

Export Citation Format

Share Document