Specifications

models - System structures
Classification code: 709 Electrical Engineering, General - 921 Mathematics
DOI: 10.1007/978-3-642-25789-6_15
Database: Compendex
Compilation and indexing terms, © 2013 Elsevier Inc.
7.
Accession number: 20133116549330
Title: A new method for loran-C ASF calculation over irregular Terrain
Authors: Zhou, Lili1 ; Xi, Xiaoli1 ; Zhang, Jinsheng2 ; Pu, Yurong1/周丽丽;席晓莉;张金生;
Author affiliation:
1 Department of Electrical Engineering, Xi'An University of Technology, 5 South Jinhua Road,
Xi'an, 710048, China
2 Xi'An High-Tech Institute, Xi'an, China
Source title: IEEE Transactions on Aerospace and Electronic Systems
Abbreviated source title: IEEE Trans. Aerosp. Electron. Syst.
Volume: 49
Issue: 3
Issue date: 2013
Publication year: 2013
Pages: 1738-1744
Article number: 6558016
Language: English
ISSN: 00189251
CODEN: IEARAX
Document type: Journal article (JA)
Publisher: Institute of Electrical and Electronics Engineers Inc., 445 Hoes Lane / P.O. Box
1331, Piscataway, NJ 08855-1331, United States
Abstract: The finite-difference time-domain (FDTD) method is employed to improve the
prediction accuracy of the Loran-C additional secondary factors (ASFs) over irregular terrains. The
FDTD method is validated by comparing the results with the theoretical method with flat Earth
formula, and then the ASFs are studied as functions of the mountain's slope gradient, height, and
width, respectively. The cases with multiple mountains in the propagation paths are also studied.
Numerical results show that when the gradient of the mountain is low, the FDTD and integral
equation methods both perform well. However, when the gradient of the mountain is rather high,
before the mountain area, the FDTD method predicts the ASFs oscillation caused by the reflected
and scattered wave from the terrains, whereas the integral equation method is not applicable.
Therefore, the FDTD method is better than the integral equation method in predicting Loran-C
signals propagating over the region with serious irregularities. The measured ASFs of Loran
signals are taken along two real paths between Pucheng and Qinling Mountains in Shaanxi
Province, China. It is found that most of the measured and FDTD results have good agreement
while some still have certain errors due to the model approximation measured. The ASFs change
rapidly in the region with serious irregularities. © 1965-2011 IEEE.
Number of references: 19
Main heading: Time domain analysis