Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Boundary Conditions: Lossless Lines01:21

Boundary Conditions: Lossless Lines

140
Consider a single-phase, two-wire, lossless transmission line terminated by an impedance at the receiving end and a source with Thevenin voltage and impedance at the sending end. The line, with length, has a surge impedance and wave velocity determined by the line's inductance and capacitance.
At the receiving end, the boundary condition states that the voltage equals the product of the receiving-end impedance and current. This relationship is expressed as a function of the incident and...
140
Lossy Lines and Overvoltages01:22

Lossy Lines and Overvoltages

118
Transmission-line series resistance and shunt conductance cause three primary effects: attenuation, distortion, and power losses.
Attenuation
When constant series resistance and shunt conductance are present, voltage and current equations are modified. The propagation constant indicates that voltage and current waves consist of both forward and backward traveling components. These waves attenuate as they propagate, with the attenuation factor related to the resistance and conductance. In a...
118
Three-Phase Short Circuit—Unloaded Synchronous Machine01:21

Three-Phase Short Circuit—Unloaded Synchronous Machine

201
Conducting a three-phase short circuit test on an unloaded synchronous machine helps understand its impact on the system. The AC fault current's oscillogram, with the DC offset removed, reveals that the waveform amplitude decreases from an initially high value to a steady-state level for one phase of the machine.
This behavior occurs due to the magnetic flux produced by the short-circuit armature currents. Initially, these currents follow high-reluctance paths but eventually shift to...
201
Small-signal Diode Model01:18

Small-signal Diode Model

969
In analyzing the behavior of diodes in circuits, the relationship between the current through a diode and the voltage across it is of particular interest, especially when considering the effect of a direct current (DC) bias voltage. When applied, this DC bias influences the diode's operating point, known as the Q point, around which the current-voltage (I-V) characteristic of the diode exhibits exponential behavior. Introducing a small, time-varying signal on top of this bias aids in...
969
Power System Three-Phase Short Circuits01:21

Power System Three-Phase Short Circuits

136
Determining the subtransient fault current in a power system involves representing transformers by their leakage reactances, transmission lines by their equivalent series reactances, and synchronous machines as constant voltage sources behind their subtransient reactances. In this analysis, certain elements are excluded, such as winding resistances, series resistances, shunt admittances, delta-Y phase shifts, armature resistance, saturation, saliency, non-rotating impedance loads, and small...
136
Insulation Coordination01:23

Insulation Coordination

207
Insulation coordination is the process of matching electric equipment's insulation strength with protective device characteristics to protect the equipment against expected overvoltages. This selection is based on engineering judgment and cost. Equipment can generally withstand short-duration high transient overvoltages, but repeated tests with identical waveforms can yield inconsistent results. As a result, standard impulse voltage waveforms are used for testing, defined by specific times...
207

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Editorial-Special Issue on "Optical and RF Atmospheric Propagation".

Sensors (Basel, Switzerland)·2023
Same author

Fast and Enhanced MMW Imaging System Using a Simple Row Detector Circuit with GDDs as Sensor Elements and an FFT-Based Signal Acquisition System.

Sensors (Basel, Switzerland)·2023
Same author

Influence of atmospheric states in semi-arid areas on hospital admission in cardio-surgical department.

International journal of biometeorology·2016
Same author

The influence of air-suspended particulate concentration on the incidence of suicide attempts and exacerbation of schizophrenia.

International journal of biometeorology·2013
Same author

The influence of several changes in atmospheric states over semi-arid areas on the incidence of mental health disorders.

International journal of biometeorology·2010
Same author

Propagation of electromagnetic waves in Kolmogorov and non-Kolmogorov atmospheric turbulence: three-layer altitude model.

Applied optics·2008

Related Experiment Video

Updated: Aug 19, 2025

Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method
07:38

Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method

Published on: April 18, 2019

31.4K

A Simple Model for Assessing Millimeter-Wave Attenuation in Brownout Conditions.

Arkadi Zilberman1,2, Natan Kopeika1

  • 1School of Electrical and Computer Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.

Sensors (Basel, Switzerland)
|November 26, 2022
PubMed
Summary

Helicopter brownout conditions pose risks during landing. Millimeter-wave (mm-wave) radar shows potential for safe navigation through dust clouds by evaluating signal attenuation and power transfer.

Keywords:
brownoutmm-wave attenuationpower transfersandstormscattering

More Related Videos

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
13:44

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers

Published on: December 27, 2012

15.4K
Effective Analysis of Human Exposure Conditions with Body-worn Dosimeters in the 2.4 GHz Band
06:43

Effective Analysis of Human Exposure Conditions with Body-worn Dosimeters in the 2.4 GHz Band

Published on: May 2, 2018

7.1K

Related Experiment Videos

Last Updated: Aug 19, 2025

Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method
07:38

Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method

Published on: April 18, 2019

31.4K
Simulation, Fabrication and Characterization of THz Metamaterial Absorbers
13:44

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers

Published on: December 27, 2012

15.4K
Effective Analysis of Human Exposure Conditions with Body-worn Dosimeters in the 2.4 GHz Band
06:43

Effective Analysis of Human Exposure Conditions with Body-worn Dosimeters in the 2.4 GHz Band

Published on: May 2, 2018

7.1K

Area of Science:

  • Aerospace Engineering
  • Electromagnetics
  • Atmospheric Physics

Background:

  • Helicopter operations in arid regions face hazards from brownout conditions, where rotor downwash creates dense dust clouds.
  • Visible and infrared sensors are ineffective in brownout, necessitating alternative navigation technologies.
  • Millimeter-wave (mm-wave) radar offers potential for penetrating atmospheric obscurants like dust.

Purpose of the Study:

  • To theoretically evaluate mm-wave attenuation, scattering, and power transfer within helicopter brownout conditions.
  • To model the impact of sand grain clouds on mm-wave propagation up to 50 meters.
  • To validate the theoretical model against field data and existing literature.

Main Methods:

  • Development of a theoretical model for mm-wave (85-100 GHz) attenuation and scattering in sand clouds.
  • Calculation of radiant flux and power transfer to the receiver.
  • Comparison of model predictions with empirical data from brownout environments.

Main Results:

  • The study provides predictions for mm-wave signal behavior in simulated brownout scenarios.
  • A simple model for estimating mm-wave power transfer demonstrated good agreement with measured values.
  • The research quantifies signal attenuation and scattering effects relevant to helicopter navigation.

Conclusions:

  • Mm-wave radar systems show promise for enabling safe helicopter operations in challenging brownout conditions.
  • Theoretical modeling provides a valuable tool for understanding and predicting mm-wave propagation in dust environments.
  • Further research and validation are supported by the satisfactory agreement between the model and real-world measurements.