Research of the wave measurement using GPS absolute velocity estimation technology

This paper analyzed the existing methods of wave measurement, and described the advantages of GPS applied in measuring the wave. The equations of absolute velocity estimation were discussed, focusing on two methods with Doppler shill. The error sources and their effect on velocity estimation were analyzed. Then, some tests were carried on to simulate dynamic velocity determination using static data Based on the high-frequency carrier-phase derived Doppler observations, the velocity has been estimated to the precision of 1 cm/s or so, even to the mm/s level. And with the receiver generated Doppler measurements, the precision can reach 3 - 15 cm/s.

Error Analysis and Accuracy Assessment of GPS Absolute Velocity Determination without SA

Error sources which decrease the accuracy of GPS in absolute velocity determination have been changed since SA was turned off. Firstly, quantities of all kinds of error sources that influence velocity deter-mination are analyzed. The potential accuracy of GPS absolute velocity determination is derived from both theory and field GPS data simulation. After that, two tests were carried out to evaluate the performance of GPS absolute velocity determination in the case of a static and an airborne GPS receiver and INS (Inertial Navigation System) instrument in kinematic mode. In static mode, the receiver velocity has been estimated to be several mm/s with the carrier-phase derived Doppler measurements, and several cm/s with the receiver generated Doppler measurements. In kinematic mode, GPS absolute velocity estimates are compared with the synchronized measurements from the high accuracy INS. The root mean square statistics of the velocity discrepancies between GPS and INS come up to dm/s. Moreover, it has a strong correlation with the accel-eration or jerk of the aircraft.

Absolute Velocity and Total Stellar Aberration

It is generally accepted that stellar annual or secular aberration is attributed to the changes in velocity of the detector. We can say it in a slightly different way. By means of the all known experiments, stellar aberration is directly or indirectly detectable and measurable, only if a detector changes its velocity. Our presumption is that stellar aberration is not caused by the changes in the velocity of the detector. It exists due to the movement of the detector regarding to an absolute inertial frame. Therefore it is just the question of how to choose such a frame. In this paper it is proposed a method to detect and measure instantaneous stellar aberration due to absolute velocity. We can call it an “absolute” stellar aberration. Combining an “annual” and an “absolute” we can define a “total” stellar aberration.

Predicting lateral displacement caused by seismic liquefaction and performing parametric sensitivity analysis:Considering cumulative absolute velocity and fine content

Lateral displacement due to liquefaction(D_(H))is the most destructive effect of earthquakes in saturated loose or semi-loose sandy soil.Among all earthquake parameters,the standardized cumulative absolute velocity(CAV_(5))exhibits the largest correlation with increasing pore water pressure and liquefaction.Furthermore,the complex effect of fine content(FC)at different values has been studied and demonstrated.Nevertheless,these two contexts have not been entered into empirical and semi-empirical models to predict D_(H)This study bridges this gap by adding CAV_(5)to the data set and developing two artificial neural network(ANN)models.The first model is based on the entire range of the parameters,whereas the second model is based on the samples with FC values that are less than the 28%critical value.The results demonstrate the higher accuracy of the second model that is developed even with less data.Additionally,according to the uncertainties in the geotechnical and earthquake parameters,sensitivity analysis was performed via Monte Carlo simulation(MCS)using the second developed ANN model that exhibited higher accuracy.The results demonstrated the significant influence of the uncertainties of earthquake parameters on predicting D_(H).

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems

We have found some mistakes in the article by Jianwei Song et al. （2007）. The revisions are given below：

The Impact of the Earth’s Movement through the Space on Measuring the Velocity of Light(Part Two)

In this paper is presented an experiment that has a goal to measure the speed of light in one direction, using one clock and one mirror. To achieve this, we have to make the measurements during the period of one year (nine months at least), taking into account earth’s movement through the space, earth’s rotation around its axis and the fact that earth spin axis is tilted with respect to the plane of its orbit of the sun.

Can a Michelson-Morley Experiment Designed with Current Solar Velocity Distinguish between Non-Relativistic and Relativistic Theories?

If Michelson were to answer the question posed in the title, given the line of reasoning he used in 1881, Michelson would seat at his desktop computer to calculate the expected fringeshifts for several solar speeds around 400 km/s and various directions of motion. Present author did exactly the same in 2001 to plan his repetition of Michelson and Morley’s (MM) 1887 experiment. The paper sketchedly summarizes the procedure to calculate expected fringeshifts in the MM interferometer for solar speeds available at Miller’s epoch. In a pre-relativistic context, amplitudes of several fringeshifts may be expected in both MM and Miller experiments. However, all interferometer experiments up to 1930 were designed under the (incorrect from a modern viewpoint) assumption that fringeshifts would be smaller than one fringe-width. The inescapable conclusion is that those experiments were not appropriate to measure the true value of solar motion, always yielding a small, but lower than expected, value for solar speed. The ensuing “negative” interpretation led to the birth of relativity theory and to a new series of experiments implicitly designed to test the relativistic hypothesis of length-contraction, while the earlier “positive” experiments were designed to test a different hypothesis: whether the motion of Earth relative to some preferred frame can be measured using an interferometer of constant dimensions. With the benefit of hindsight this writer repeated the MM experiment, correcting main weaknesses identified up to the Michelson-Morley-Miller (MMM) measurements at Mount Wilson from April 1925 to February 1926. A new possible reinterpretation of the MMM data as a sequence of stationary measurements is pointed out. Our Michelson-Morley-Miller-Munera (MMMM) experiment at Bogota (Colombia) from January 2003 to June 2005 gave values for solar absolute velocity in the same range as those obtained by astronomical means. Surprisingly, our results are compatible with modern third-party MM-type experiments designed and interpreted within relativistic contexts. Thus, a so far unexplored possibility arises: can interferometric experiments distinguish between pre-relativistic and relativistic theories? Our answer is negative.

Principal-component estimates of the Kuroshio Current axis and path based on the mathematical verification between satellite altimeter and drifting buoy data

We used satellite altimetry data to investigate the Kuroshio Current because of the higher resolution and wider range of observations. In previous studies, satellite absolute geostrophic velocities were used to study the spatiotemporal variability of the sea surface velocity field along the current, and extraction methods were employed to detect the Kuroshio axes and paths. However, sea surface absolute geostrophic velocity estimated from absolute dynamic topography should be regarded as the geostrophic component of the actual surface velocity, which cannot represent a sea surface current accurately. In this study, mathematical verification between the climatic absolute geostrophic and bin-averaged drifting buoy velocity was established and then adopted to correct the satellite absolute geostrophic velocities. There were some differences in the characteristics between satellite geostrophic and drifting buoy velocities. As a result, the corrected satellite absolute geostrophic velocities were used to detect the Kuroshio axis and path based on a principal-component detection scheme. The results showed that the detection of the Kuroshio axes and paths from corrected absolute geostrophic velocities performed better than those from satellite absolute geostrophic velocities and surface current estimations. The corrected satellite absolute geostrophic velocity may therefore contribute to more precise day-to-day detection of the Kuroshio Current axis and path.