POSITION FINDING BY RATE OF CHANGE OF ALTITUDE OF THE SUN

Survey Review ◽  
1978 ◽  
Vol 24 (189) ◽  
pp. 323-325
Author(s):  
R. F. Rish
Keyword(s):  
Rate Of Change ◽  
The Sun

Low selenocentric orbits stability analysis

2020 ◽  
Author(s):  
Chongrui Du ◽  
O.L. Starinova
Keyword(s):  
Rate Of Change ◽  
The Sun ◽  
Space Systems ◽  
The Moon ◽  
Orbital Structure ◽  
Motion Modeling ◽  
The Earth ◽  
Long Time ◽  
The Stability

The tasks of studying the Moon require long-term functioning space systems. Most of the low selenocentric orbits are known to be unstable, which requires a propellant to maintain the orbital structure. For these orbits, the main disturbing factors are the off-center gravitational field of the Moon and the gravity of the Earth and the Sun. This paper analyzes the stability of low selenocentric orbits according to passive motion modeling and takes into account these main disturbing factors. We put forward a criterion for determining the stability of the orbit and used it to analyze the circular orbit of the Moon at an altitude of 100 kilometers. According to different initial data and different dates, we obtained ranges of the Moon’s orbits with good stability. At the same time, we analyzed the rate of change in the longitude of the ascending node, and found a stable low lunar orbit which can operate for a long time.

The vowels of Brunei English

2006 ◽  
Vol 27 (3) ◽  
pp. 247-264 ◽  
Author(s):  
Salbrina Sharbawi
Keyword(s):  
Rate Of Change ◽  
The Sun ◽  
British English ◽  
Common Features ◽  
The North ◽  
North Wind

This paper provides an acoustic description of the vowels of Brunei English (BrunE). Ten female BrunE speakers were recorded reading The North Wind and the Sun (NWS) passage. The formant values of the eleven monophthong vowels and the rate of change (ROC) of the diphthong /eI/ were measured and compared with the data of seven British English (BrE) speakers and also the results of similar studies on Singapore English (SgE). It was found that BrunE shares some common features with SgE as both groups do not distinguish between /i˜/ and /I/, /e/ and /æ/, and /f˜/ and /#/. The high back vowels of BrunE, however, are unlike the SgE vowels. Whereas in SgE /u˜/ and /~/ are fully back, in BrunE these two vowels are fronted, so they are similar to the vowels of the BrE speakers. The data also shows that BrunE /f˜/ is more open and less back than BrE /f˜/. For /eI/, the average ROC for Bruneian speakers is considerably less negative than that for British speakers, which indicates that in BrunE, just as in SgE, this vowel is less diphthongal than its counterpart in BrE.

High Altitude Observations at Sea

1951 ◽  
Vol 4 (02) ◽  
pp. 165-166
Author(s):  
A. N. Black
Keyword(s):  
High Altitude ◽  
Maximum Error ◽  
Sufficient Accuracy ◽  
Rate Of Change ◽  
Zenith Distance ◽  
The Sun ◽  
High Altitudes ◽  
Short Period ◽  
Very High

It is difficult to get satisfactory noon observations when the zenith distance is very small, because the Sun is rapidly changing in azimuth, the sextant must be swung through a wide arc of the horizon, and the Sun only dwells at the highest altitude for a very short period. To avoid these difficulties it is suggested that, instead of trying to measure the altitude of the Sun, one should measure its distance from a point on the horizon in a known azimuth. To make this measurement the Sun is brought down to the required point on the horizon, tilting the sextant as necessary; we shall distinguish this type of observation from the normal one, made with the sextant vertical, by calling the angle so obtained thehorizon distance. At normal altitudes this method, however sound in theory, breaks down because one cannot measure the azimuth with sufficient accuracy. However, at very high altitudes the rate of change of horizon distance with change of azimuth of the point from which the distance is measured becomes so small that it is not necessary to know the azimuth with such precision. In fact, at a zenith distance of 1°, the largest we shall consider here, the greatest error caused by an error of 1° in the azimuth is l″, and for smaller zenith distances the maximum error is proportionately less.

Eclipses and the Earth’s Rotation

2018 ◽  
Vol 14 (A30) ◽  
pp. 160-162
Author(s):  
F. R. Stephenson ◽  
L. V. Morrison ◽  
C. Y. Hohenkerk
Keyword(s):  
Time Scale ◽  
Average Rate ◽  
Smooth Curve ◽  
Rate Of Change ◽  
Time Difference ◽  
The Sun ◽  
Historical Records ◽  
Tidal Friction ◽  
First Derivative ◽  
Length Of The Day

AbstractAnalysis of historical records of eclipses of the Sun and Moon between 720 BC and AD 1600 gives a measure of the time difference, TT − UT = ΔT. The first derivative in time along a smooth curve fitted to the values of Δ T measures the changes in the length of the day (lod). The average rate of change of the lod is found to be significantly less than that expected on the basis of tidal friction. Fluctuations on a time-scale of centuries to millennia are mainly attributed to the effects of post-glacial uplift and core-mantle coupling.

Introduction

1999 ◽  
Author(s):  
Yuk L. Yung ◽  
William B. DeMore
Keyword(s):  
Solar System ◽  
Solar Radiation ◽  
Atmospheric Chemistry ◽  
Past History ◽  
Chemical Change ◽  
Visible Spectrum ◽  
Rate Of Change ◽  
The Sun ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere

It is usual in the study of planets to consider the Earth first, and then the other planets, so that we can better understand how and why the rest of the solar system is different from us. In this book the order of study will be reversed: we shall first try to understand the solar system, and then we will ask why Earth is unique. We adopt this unconventional approach for two reasons. First, Earth's atmosphere today is the end-point of an evolution that started about 4.6 billion years ago. The pristine materials have all been drastically altered. However, by examining other parts of the solar system that have evolved to a lesser degree, we may deduce what the early Earth might have been like. Second, Earth's atmosphere today is largely determined by the complex biosphere, whose evolution has been intimately coupled to that of the atmosphere. In other words, ours is the only atmosphere in the solar system that supports life, and it is in turn modified by life. Therefore, to appreciate the beauty and the intricacy of our planet, we must start with simpler objects without life. Chemical composition is intimately connected to evolution, which in turn is driven by chemical change. In this book we attempt to provide a coherent basis for understanding the planetary atmospheres, to identify the principal chemical cycles that control their present composition and past history. Figure 1.1 gives an illustration of the intellectual framework in which our field of study is embedded. The unifying theme that connects the planets in the solar system is "origin"; that is, all planets share a common origin about 4.6 billion years ago. The subsequent divergence in the solar system may be partly attributed to evolution, driven primarily by solar radiation. The bulk of solar radiation consists of photons in the visible spectrum with a mean blackbody radiation temperature of 5800 K. The part that is responsible for direct atmospheric chemistry is a tiny portion (less than 1% of the total flux) in the ultraviolet. In addition, the sun emits a steady stream of corpuscular particles, known as the solar wind. While the sun provides the principal source of energy for change, the time rate of change is crucial, and that is where chemical kinetics and chemical cycles play pivotal roles.

scholarly journals Latitude by Maximum Altitude

1965 ◽  
Vol 18 (2) ◽  
pp. 241-243
Author(s):  
J. W. Crosbie
Keyword(s):  
Traditional Method ◽  
Rate Of Change ◽  
The Body ◽  
The Sun ◽  
The Earth ◽  
Geographical Position

Latitude by meridian altitude is one of the commonest position lines used in the Merchant Navy today, and the traditional method of obtaining it is to observe the Sun until it reaches maximum altitude, at which point it is said to dip. With the advent of power-driven vessels, however, this method became liable to an error of 5 minutes of arc, and as faster surface craft are developed it is reasonable to assume that the error could be even greater. This is because the rate of change of altitude of a body is related to the observer's speed over the Earth so that the body will dip either before or after meridian passage depending on whether the observer is moving towards or away from the geographical position of the Sun.

scholarly journals Evolution of space debris for spacecraft in the Sun-synchronous orbit

2020 ◽  
Vol 29 (1) ◽  
pp. 265-274
Author(s):  
Yu Jiang ◽  
Hengnian Li ◽  
Yue Yang
Keyword(s):  
Space Debris ◽  
Rate Of Change ◽  
The Sun ◽  
Orbital Parameters ◽  
Velocity Error ◽  
Synchronous Orbit ◽  
The Right ◽  
The Impact ◽  
Impact Motion ◽  
Right Ascension

AbstractIn this paper, the evolution of space debris for spacecraft in the Sun-Synchronous orbit has been investigated. The impact motion, the evolution of debris from the Sun-Synchronous orbit, as well as the evolution of debris clouds from the quasi-Sun-Synchronous orbit have been studied. The formulas to calculate the evolution of debris objects have been derived. The relative relationships of the velocity error and the rate of change of the right ascension of the ascending node have been presented. Three debris objects with different orbital parameters have been selected to investigate the evolution of space debris caused by the Sun-Synchronous orbit. The debris objects may stay in quasi-Sun-Synchronous orbits or non-Sun-Synchronous orbits, which depend on the initial velocity errors of these objects.

scholarly journals Application of the wavelet phase method of signal study to the analysis of asymmetric barycentric motions of the Sun and changes in processes occurring on the Sun, near-earth space and in the interior of the Earth

2021 ◽  
Vol 16 (3) ◽  
pp. 7-35
Author(s):  
Valeriy I. Alekseev
Keyword(s):  
Solar Activity ◽  
Solar System ◽  
Cosmic Ray ◽  
Volcanic Eruptions ◽  
Rate Of Change ◽  
Phase Method ◽  
The Sun ◽  
Correlation Matrices ◽  
Solar Systems ◽  
The Earth

A set of studies has been carried out, indicating that solar activity and processes associated with the activity of the Sun: changes in the main magnetic fluxes, areas of polar spots, the number of polar torches at the poles of the Sun; -index of geomagnetic activity and -index of the ratio of plasma pressure to magnetic solar wind (SW), slow and high-speed flows of SW, cosmic ray intensity (CR); average annual values of the interplanetary magnetic field vector and its components; the temperature, density, and flow rate of the SW plasma, the synodic period of the revolution of the Sun as a star, and the radius of the Sun in relative units; the distance of the Earths geographic pole from the conventional international origin, the rate of change of the position of the Earths north magnetic pole, the main ionospheric parameters; the angle of the Earth's axis of rotation and volcanic eruptions; asymmetric movement of the Sun around the solar system of the solar system (in fractions of the solar radius); the distances from the solar systems CM to the Sun in km, the distances from the solar systems CM to the Earth, with high accuracy, are consistent with the movement of the Sun relative to the barycenter. The research is based on the wavelet transformation of the observations listed above variables in various time intervals with the subsequent calculation of their phase-frequency and phase-time characteristics, correlation matrices between characteristics. The studied variables are divided into groups, which include the barycentric movement of the Sun and changes in solar activity. The calculated two correlation matrices of the wavelet characteristics of the group of variables and the graphs of these characteristics in two coordinate systems reflect the consistency of changes in the group. The studies carried out indicate that the thermonuclear reaction occurring in the interior of the Sun, the external manifestation of which is solar activity, is controlled by the movements of the large planets of the Solar System relative to the Sun.

The contraction of satellite orbits under the influence of air drag V. With day-to-night variation in air density

1965 ◽  
Vol 259 (1096) ◽  
pp. 33-67 ◽  
Keyword(s):  
Orbital Period ◽  
Angular Distance ◽  
Maximum Density ◽  
Rate Of Change ◽  
Satellite Orbits ◽  
The Sun ◽  
Air Drag ◽  
Air Density ◽  
Main Geometrical Parameter ◽  
Long Term Effect

The effect of air drag on satellite orbits of small eccentricity (< 0-2) was studied in part I on the assumption that the atmosphere was spherically symmetrical. In reality the density of the upper atmosphere depends on the elevation of the Sun above the horizon and has a maximum when the Sun is almost overhead. In the present paper the theory is extended to an atmosphere in which the air density at a given height varies sinusoidally with the geocentric angular distance from the maximum-density direction. Equations are derived which show how perigee distance and orbital period vary with eccentricity throughout the satellite’s life, and how eccentricity varies with time. Expressions are also obtained for lifetime and air density at perigee in terms of the rate of change of orbital period. The main geometrical parameter determining the long-term effect of this day-to-night variation is the angular distance <f>p of perigee from the maximum-density direction. Results are obtained for <})pconstant and <j)pvarying linearly with time.

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