scholarly journals Calculation of sunrise and sunset times at ionospheric heights along a great circle path

1964 ◽  
Author(s):  
A H Brady
Keyword(s):  
Great Circle ◽  
Great Circle Path

The Vector Function for Distance Travelled in Great Circle Navigation

2006 ◽  
Vol 60 (1) ◽  
pp. 158-164 ◽  
Author(s):  
Wei-Kuo Tseng ◽  
Hsuan-Shih Lee
Keyword(s):  
Linear Combination ◽  
Vector Function ◽  
Personal Computer ◽  
Great Circle ◽  
Departure Point ◽  
Easy Method ◽  
Vector Algebra ◽  
Elementary Knowledge ◽  
Vector Basis ◽  
Great Circle Path

Traditionally, on a great circle, the latitude or longitude of a waypoint is found by inspection. In this paper, using an elementary knowledge of vector algebra including linear combination of vectors and vector basis, we provide an easy method for finding the equation of a great circle path as a parameterized curve. By use of this vector function of distance travelled, the latitude and longitude of waypoints can be found based on the distance from departure point along a great circle. The approach is intended to appeal to the navigator who is interested in the mathematics of navigation and who, nowadays, solves his navigation problems with a personal computer.

The Coriolis Effect

1953 ◽  
Vol 57 (514) ◽  
pp. 655-658
Author(s):  
Paul E. Wylie
Keyword(s):  
Great Circle ◽  
The Body ◽  
Coriolis Effect ◽  
Deflection Of The Vertical ◽  
Horizontal Acceleration ◽  
The Earth ◽  
Moving Body ◽  
Great Circle Path

The coriolis effect is a change in the motion of a body passing over the surface of the Earth due to the motion of the Earth itself. The effect may be manifested either as a horizontal acceleration, or, in the absence of the acceleration, as a deflection of the course. The acceleration, which appears in controlled courses such as those of aircraft, usually appears and is significant as a deflection of the vertical. This acceleration appears whenever a body, such as an aircraft, is forced to follow a great circle path over the Earth. The deflection of the course of a moving body appears alternatively whenever the body moves freely in its inertial path above the surface of the moving Earth.

High Rayleigh wave phase velocities for the New Delhi, India-Lahore, Pakistan profile

1966 ◽  
Vol 56 (5) ◽  
pp. 1137-1145
Author(s):  
V. G. Gabriel ◽  
John T. Kuo
Keyword(s):  
Phase Velocity ◽  
Structural Model ◽  
Great Circle ◽  
New Delhi ◽  
Indian Shield ◽  
Phase Velocities ◽  
Local Geology ◽  
Using Data ◽  
Great Circle Path ◽  
High Phase

Abstract Phase velocities were determined for the New Delhi-Lahore profile by using data from these two stations and earthquakes located approximately on the great circle path through the stations. The phase velocities were found to be higher than those expected for normal continental structures and somewhat similar to those found by Brune and Dorman (1963) for the Canadian shield. A structural model, based on the phase velocity values of the CANSD model given by Brune and Dorman (1963) and consistent with the local geology, was evaluated and is presented herewith as the INDSD model. It is postulated that high phase velocity values in the Lahore-New Delhi profile indicate the shield character of the crustal structure along the profile, as an extension of the Indian shield located south and southeast of it.

Tripartite results for the Kamchatka earthquake of November 4, 1952*

1955 ◽  
Vol 45 (3) ◽  
pp. 167-178
Author(s):  
Jack F. Evernden
Keyword(s):  
Love Wave ◽  
Random Motion ◽  
Great Circle ◽  
Kamchatka Earthquake ◽  
Great Circle Path

Abstract The tripartite technique was applied to all parts of the record following initial S. The results of this study indicate: (1) that the SV motion, extending from initial S to G, was a cohesive whole, not random motion, and is the result of continuous arrival of energy along paths of decreasing mantle penetration; and (2) that the SV-, Rayleigh-, and Love-wave arrivals were all deflected from the great-circle path. These results contrast sharply with results of earlier tripartite studies. The deflection is tentatively explained by a general downwarping of the equalvelocity surfaces in the mantle in the vicinity of the Aleutian tectonic welt.

A STUDY OF TRANSATLANTIC RADIO PROPAGATION MODES AT 41.5 MC/S

1963 ◽  
Vol 41 (2) ◽  
pp. 220-233 ◽  
Author(s):  
E. L. Hagg ◽  
W. Rolfe
Keyword(s):  
Control Point ◽  
Signal Strength ◽  
Ground Level ◽  
Auroral Zone ◽  
Great Circle ◽  
Radio Propagation ◽  
Transmitted Power ◽  
Sound Channel ◽  
The North ◽  
Great Circle Path

Both great-circle and off-path propagation modes have been investigated on a transatlantic path. Measurements of signal strength and azimuthal bearing were made at Ottawa, Canada, on the 41.5-Mc/s BBC TV sound channel transmissions during the winter months of 1957–58. The predominant signal was found to be a ground (land or sea) sidescatter signal arriving about 35° to the south of the great circle path. The presence of this signal can be explained qualitatively by ground-level focusing near the intersection of the receiver and transmitter skip distances.A secondary off-path signal, arriving about 7° to the north of the great circle path, was observed. This signal may be ionospheric sidescatter from irregularities in the auroral zone. It is suggested that the ionospheric sidescatter is analogous to ground sidescatter since focusing is not restricted to ground level.It is shown that the method using the two-hop geometric great circle path is superior to the 2000-km control-point method for predicting monthly median transatlantic maximum usable frequencies during winter daytime when low to moderate transmitted power is used.

scholarly journals Waveguide Parameters of 19.8 kHz Signal Propagating over a Long Path

2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Sushil Kumar
Keyword(s):  
Wave Propagation ◽  
Waveguide Mode ◽  
Great Circle ◽  
Propagation Path ◽  
Mode Theory ◽  
North West ◽  
Path Distance ◽  
Experimental Values ◽  
Great Circle Path

The amplitude and phase of 19.8 kHz signal from navigational transmitter located in North West Cape, Australia, recorded at Suva, Fiji, have been utilized to determine the waveguide mode parameters. The propagation path is mixed over land and sea having Transmitter-Receiver Great Circle Path distance 6.7 Mm. The experimental values of the parameters were found to be consistent with the theoretical values calculated using the mode theory of VLF wave propagation in the waveguide.

A crust-mantle profile from Mould Bay, Canada, to Tucson, Arizona

1968 ◽  
Vol 58 (6) ◽  
pp. 1821-1831
Author(s):  
A. J. Wickens ◽  
K. Pec
Keyword(s):  
Phase Velocity ◽  
Upper Mantle ◽  
Love Wave ◽  
Great Circle ◽  
Careful Selection ◽  
Precambrian Shield ◽  
Phase Velocities ◽  
Wave Phase ◽  
Adjacent Segments ◽  
Great Circle Path

ABSTRACT Love-wave phase velocities were determined for five adjacent segments of a 5000 kilometer great circle path from Mould Bay, Canada, to Tucson, Arizona. Mean-phase velocity curves were obtained from curves based on reciprocal data, thus minimizing the detrimental effects of non-parallel layering. By careful selection and precise treatment of the data over relatively short distances (800 km), detail hitherto suppressed has been retained. Finally, by using reciprocal seismograms, the effect of sloping interfaces was observed. The crustal and upper mantle models obtained indicate significant differences in structure between different provinces of the Precambrian Shield.

The determination of S-wave polarization angles for an earth model with crustal layering

1964 ◽  
Vol 54 (5A) ◽  
pp. 1429-1440 ◽  
Author(s):  
Otto Nuttli
Keyword(s):  
Epicentral Distance ◽  
Vertical Axis ◽  
Great Circle ◽  
Earth Model ◽  
Polarization Angle ◽  
Wave Surface ◽  
S Wave ◽  
Surface Motion ◽  
Seismograph Station ◽  
Great Circle Path

Abstract This paper presents a method for determining the polarization angle of S waves which takes account of the crustal layering at the seismograph station. Charts are given for four crustal models, corresponding to normal continental, thick, and thin crusts, which enable one to obtain the polarization angle at the top of the mantle beneath the seismograph station. The equations to be used for obtaining the polarization angle are tan ∈ = F h tan γ tan ∈ = F v tan δ where ε is the polarization angle, γ is the angle between the horizontal component of the S-wave surface motion and the great circle path at the station, δ is the angle between the vertical axis and the component of the S-wave surface motion in the plane transverse to the great circle path, and Fh and Fv are functions of wave period, epicentral distance, and the crustal structure at the seismograph station. Values of Fh and Fv for four crustal models are given in the paper.

Deviation of decameter radio waves from the great circle path at high latitudes

1991 ◽  
Vol 34 (2) ◽  
pp. 102-105
Author(s):  
N. F. Blagoveshchenskaya ◽  
A. N. Baranets ◽  
T. D. Borisova ◽  
V. A. Bubnov
Keyword(s):  
Great Circle ◽  
High Latitudes ◽  
Radio Waves ◽  
Decameter Radio ◽  
Great Circle Path
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