Comparison of irregular variations in the Earth’s rotation rate and parameters of geophysical and atmospheric processes with events on the sun

This paper investigates resonances in the perturbations of a synchronous satellite including its latitude, angular rate of the earth-moon system around the sun and the earth’s rotation rate about its axis. This is found that resonances occur due to the commensurability between (i) angular velocity of the satellite and angular rate of earth’s rotation about its axis and (ii) angular rate of the earth-moon system around the sun and angular rate of the rotation of the earth. Amplitude and time-period of the oscillation at the resonance points are determined using the procedure of Brown and Shook [3]. Effect of (orbital angle of the mass-centre of the earth-moon system around the sun) on amplitude and time period is also analyzed. It is found that for increasing the values of from to amplitude decreases and time period also decreases. Effect of time on the latitude of the satellite including earth oblateness is also studied. It is seen that for increasing the value of , there is a small change in , the latitude of the synchronous satellite.

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SINS Installation Error Calibration Based on Multi-Position Combinations

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.4213 ◽

2011 ◽

Vol 383-390 ◽

pp. 4213-4220

Author(s):

Zhen Huan Wang ◽

Xi Jun Chen ◽

Qing Shuang Zeng

Keyword(s):

Theoretical Analysis ◽

Least Squares ◽

Rotation Rate ◽

Scale Factor ◽

New Method ◽

Earth’S Rotation ◽

Earth's Rotation ◽

Error Calibration ◽

Sine And Cosine Functions ◽

Cosine Functions

A new method is proposed to calibrate the installation errors of SINS. According to the method, the installation errors of the gyro and accelerometer can be calibrated simultaneously, which not depend on latitude, gravity, scale factor and earth's rotation rate. By the multi-position combinations, the installation errors of the gyro and accelerometer are modulated into the sine and cosine functions, which can be identified respectively based on the least squares. In order to verify the correctness of the theoretical analysis, the SINS is experimented by a three-axis turntable, and the installation errors of the gyro and accelerometer are identified respectively according to the proposed method. After the compensation of the installation error, the accuracy of the SINS is improved significantly.

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Addendum 2020 to ‘Measurement of the Earth’s rotation: 720 BC to AD 2015’

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2020.0776 ◽

2021 ◽

Vol 477 (2246) ◽

pp. 20200776

Author(s):

L. V. Morrison ◽

F. R. Stephenson ◽

C. Y. Hohenkerk ◽

M. Zawilski

Keyword(s):

Angular Momentum ◽

Earth’S Rotation ◽

The Sun ◽

Earth's Rotation ◽

Moon System ◽

Link Type ◽

The Earth ◽

Solar Eclipses ◽

Rotation Of The Earth

Historical reports of solar eclipses are added to our previous dataset (Stephenson et al. 2016 Proc. R. Soc. A 472 , 20160404 ( doi:10.1098/rspa.2016.0404 )) in order to refine our determination of centennial and longer-term changes since 720 BC in the rate of rotation of the Earth. The revised observed deceleration is −4.59 ± 0.08 × 10 −22 rad s −2 . By comparison the predicted tidal deceleration based on the conservation of angular momentum in the Sun–Earth–Moon system is −6.39 ± 0.03 × 10 −22 rad s −2 . These signify a mean accelerative component of +1.8 ± 0.1 × 10 −22 rad s −2 . There is also evidence of an oscillatory variation in the rate with a period of about 14 centuries.

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