Reversed and anomalous Doppler shifts in periodic media

2005 ◽  
Author(s):  
Evan J. Reed ◽  
Marin Soljacic ◽  
Mihai Ibanescu ◽  
John D. Joannopoulos
Keyword(s):  
Periodic Media ◽  
Doppler Shifts

Nonlinear Pulse Propagation and Modulation Instability in Periodic Media with and without Defects

PIERS Online ◽  
2006 ◽  
Vol 2 (2) ◽  
pp. 177-181
Author(s):  
V. Grimalsky ◽  
Svetlana Koshevaya ◽  
Javier Sanchez-Mondragon ◽  
Margarita Tecpoyotl Torres ◽  
J. Escobedo Alatorre
Keyword(s):  
Pulse Propagation ◽  
Modulation Instability ◽  
Periodic Media ◽  
Nonlinear Pulse Propagation

scholarly journals Line-of-Sight Winds and Doppler Effect Smearing in ACE-FTS Solar Occultation Measurements

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 680
Author(s):  
Chris D. Boone ◽  
Johnathan Steffen ◽  
Jeff Crouse ◽  
Peter F. Bernath
Keyword(s):  
Atmospheric Chemistry ◽  
Doppler Effect ◽  
Line Of Sight ◽  
Measured Signal ◽  
Mixing Ratio ◽  
Model Calculations ◽  
Doppler Shifts ◽  
Solar Occultation ◽  
Wide Range ◽  
Wind Profiles

Line-of-sight wind profiles are derived from Doppler shifts in infrared solar occultation measurements from the Atmospheric Chemistry Experiment Fourier transform spectrometers (ACE-FTS), the primary instrument on SCISAT, a satellite-based mission for monitoring the Earth’s atmosphere. Comparisons suggest a possible eastward bias from 20 m/s to 30 m/s in ACE-FTS results above 80 km relative to some datasets but no persistent bias relative to other datasets. For instruments operating in a limb geometry, looking through a wide range of altitudes, smearing of the Doppler effect along the line of sight can impact the measured signal, particularly for saturated absorption lines. Implications of Doppler effect smearing are investigated for forward model calculations and volume mixing ratio retrievals. Effects are generally small enough to be safely ignored, except for molecules having a large overhang in their volume mixing ratio profile, such as carbon monoxide.

scholarly journals Characterizing the Impact of Doppler Effects on Body-Centric LoRa Links with SDR

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4049
Author(s):  
Thomas Ameloot ◽  
Marc Moeneclaey ◽  
Patrick Van Van Torre ◽  
Hendrik Rogier
Keyword(s):  
Wireless Communication ◽  
Low Power ◽  
Multipath Fading ◽  
Doppler Spread ◽  
Excellent Performance ◽  
Wireless Applications ◽  
Doppler Shifts ◽  
Doppler Effects ◽  
The Impact ◽  
Measurement Campaigns

Long-range, low-power wireless technologies such as LoRa have been shown to exhibit excellent performance when applied in body-centric wireless applications. However, the robustness of LoRa technology to Doppler spread has recently been called into question by a number of researchers. This paper evaluates the impact of static and dynamic Doppler shifts on a simulated LoRa symbol detector and two types of simulated LoRa receivers. The results are interpreted specifically for body-centric applications and confirm that, in most application environments, pure Doppler effects are unlikely to severely disrupt wireless communication, confirming previous research, which stated that the link deteriorations observed in a number of practical LoRa measurement campaigns would mainly be caused by multipath fading effects. Yet, dynamic Doppler shifts, which occur as a result of the relative acceleration between communicating nodes, are also shown to contribute to link degradation. This is especially so for higher LoRa spreading factors and larger packet sizes.

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