Measurements of the Propagation Time of Loran-C Signals
Abstract
LORAN-C signals of Iwo Jima (9970-M) and Hokkaido (9970-X) of the Northwest Pacific chain were received at 21 locations in northern Japan to estimate the accuracy of time comparison by the LORAN-C method. The distance between transmitting sites and receiving sites ranges from 24 km (9970-X to Onbetsu, Hokkaido) to 1777 km (9970-M to Ajigasawa, Aomori). The Navy Navigation Satellite System was used to determine the antenna location to an accuracy of +/- 10 m, which is necessary to estimate the propagation time. The secondary phase is calculated by the Millington-Pressey method using Brunavs's approximate formula for secondary phase computation and an effective conductivity map. The phase delay shows a general tendency of + 0.66 microseconds per 100 km with resect to a wave moving at vacuum velocity. The range of deviation is +/- 0.6 microseconds. The observed phase shows the additional delay of about 0.35 microseconds per 100 km. With this correction applied, the observed phase deviates usually in the range of +/- 0.5 microseconds. However, sometimes the observed phase shows deviations as much as +/- 1.5 microseconds, which seem to be due to the terrain effect.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA521033
Entities
People
- Katsuhisa Sato
- Kazuyoshi Asari
- Kenzaburo Iwadate
- Koji Horiai
- Mitsumi Fujishita
- Satoshi Sakai
- Tadayoshi Hara