Fade statistics and propagation events atCband for two overwater, line-of-sight propagation paths over a 1-year period

Radio Science ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 813-828 ◽  
Author(s):  
Julius Goldhirsh ◽  
G. Daniel Dockery ◽  
Bert H. Musiani
Keyword(s):  
Line Of Sight ◽  
Line Of Sight Propagation ◽  
Propagation Paths ◽  
Fade Statistics

scholarly journals Stochastic relation between anomalous propagation in the line-of-sight VHF radio band and occurrences of earthquakes

2014 ◽  
Vol 14 (8) ◽  
pp. 2119-2124 ◽  
Author(s):  
K. Motojima ◽  
N. Haga
Keyword(s):  
Line Of Sight ◽  
Very High Frequency ◽  
Radio Broadcasting ◽  
Fm Radio ◽  
Line Of Sight Propagation ◽  
Propagation Paths ◽  
Anomalous Propagation ◽  
Radio Band ◽  
Very High

Abstract. This paper was intended to find out any relation between anomalous line-of-sight propagation on the very high frequency (VHF) band and occurrences of earthquakes near the VHF propagation paths. The television and FM radio broadcasting waves on the VHF band were monitored continuously over the long term. For that purpose, a multidirectional VHF band monitoring system was established and utilized. Anomalous line-of-sight propagation on the VHF band was distinguished from the monitored wave by using a statistical analysis. After the stochastic consideration, it was found out that earthquakes associated with anomalous propagation were characterized by magnitude of earthquakes M ≥ 4.5, and distances from epicenters L ≤ 75 km. The anomalous propagation was monitored on the VHF band a few days before the associated earthquakes occurred. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously. The anomaly on the line-of-sight propagation indicates the possibility of narrowly focusing the area of the epicenter of earthquake.

scholarly journals Stochastic relation between anomalous propagation in the line-of-sight VHF radio band and occurrences of earthquakes

2013 ◽  
Vol 1 (6) ◽  
pp. 6829-6848
Author(s):  
K. Motojima ◽  
N. Haga
Keyword(s):  
Statistical Analysis ◽  
Monitoring System ◽  
Line Of Sight ◽  
Radio Broadcasting ◽  
Fm Radio ◽  
Line Of Sight Propagation ◽  
Propagation Paths ◽  
Anomalous Propagation ◽  
Radio Band

Abstract. This paper was intended to find out any relation between anomalous line-of-sight propagation on the VHF band and occurrences of earthquakes near the VHF propagation paths. The television and FM radio broadcasting waves on the VHF band were monitored continuously over the long term. For that purpose, a multidirectional VHF band monitoring system was established and utilized. Anomalous line-of-sight propagation on the VHF band was distinguished from the monitored wave by using a statistical analysis. After the stochastic consideration, it was found out that earthquakes associated with anomalous propagation were characterized by magnitude of earthquakes M ≥ 4.5, and distances from epicenters L ≤ 75 km. The anomalous propagation was monitored on the VHF band a few days earlier the associated earthquakes occurred. Moreover, the anomaly appeared on multidirectional propagation paths simultaneously. The anomaly on the line-of-sight propagation indicates possibility of narrow focusing the area of epicenter of earthquake.

Three years of C band signal measurements for overwater, line-of-sight links in the mid-Atlantic coast: 1. Fade statistics

Radio Science ◽  
1994 ◽  
Vol 29 (6) ◽  
pp. 1421-1431 ◽  
Author(s):  
Julius Goldhirsh ◽  
G. Daniel Dockery ◽  
Bert H. Musiani
Keyword(s):  
Atlantic Coast ◽  
Line Of Sight ◽  
Fade Statistics ◽  
Band Signal

IMU-Aided Dual-Frequency RFID Based Localization in LOS/NLOS Hybrid Environment

2017 ◽  
Author(s):  
Jie Wu ◽  
MingHua Zhu ◽  
Bo Xiao ◽  
Wei He
Keyword(s):  
Indoor Localization ◽  
Measurement Unit ◽  
Line Of Sight ◽  
Dual Frequency ◽  
Site Survey ◽  
Line Of Sight Propagation ◽  
The Mean ◽  
Position Precision ◽  
Rf Signal ◽  
Non Line Of Sight

The mitigation of NLOS (non-line-of-sight) propagation conditions is one of main challenges in wireless signals based indoor localization. When RFID localization technology is applied in applications, RSS fluctuates frequently due to the shade and multipath effect of RF signal, which could result in localization inaccuracy. In particularly, when tags carriers are walking in LOS (line-of-sight) and NLOS hybrid environment, great attenuation of RSS will happen, which would result in great location deviation. The paper proposes an IMU-assisted (Inertial Measurement Unit) RFID based indoor localization in LOS/NLOS hybrid environment. The proposed method includes three improvements over previous RSS based positioning methods: IMU aided RSS filtering, IMU aided LOS/NLOS distinguishing and IMU aided LOS/NLOS environment switching. Also, CRLB (Cramér-Rao Low Bound) is calculated to prove theoretically that indoor positioning accuracy for proposed method in LOS/NLOS mixed environment is higher than position precision of only use RSS information. Simulation and experiments are conducted to show that proposed method can reduce the mean positioning error to around 3 meters without site survey.

Sign in / Sign up

Export Citation Format

Share Document