Tech Explorist’s Post

The electrostatically charged dust and magnetic anomalies will be a challenge. https://lnkd.in/gGJexGMV

Errors in Navigational Models Could Have an Easy Answer... Lingering issues in magnetic field models may be from oversampling data.

Researchers have put forth a new technique for creating spatially structured light beams in which the polarization continually and longitudinally varies along any transmission path. Along a same helical transmission trajectory, one shows continuous variation in polarization states from 15° linear polarization to 75° linear polarization, while the other consistently transitions from 15° linear polarization to RCP and then back to 75° linear polarization. View original article https://lnkd.in/grBBsTJq Generation of structured light beams with polarization variation along arbitrary spatial trajectories using tri-layer metasurfaces

Because of the strong flows and current systems surrounding and within auroral arcs, plasma turbulence can develop, causing the formation of small scale plasma structures that can interfere with communications, remote sensing, and navigation signals passing in their vicinity. In our recent work with Magnus Ivarsen we were able to show that turbulence predominantly forms around the edges of auroral arcs rather than inside of them and can even occur before optical aurora are visible. We believe this to be the result of Farley-Buneman instability, where the plasma drift is faster than the local ion speed of sound, causing a sort of Kelvin-Helmholtz-like instability to form on the sides of auroral arcs. The paper (https://lnkd.in/evcRV2kk) goes into much greater detail but for illustration, here's a video of backscatter from meter-scale plasma irregularities (red-yellow) along with some beautiful green auroral imagery showing how these regions of turbulence develop around the auroral arcs. We hope that this and future work will allow us to better understand the turbulent mechanisms that cause backscatter and clutter in high latitude Over-The-Horizon Radar (OTHR), as well as interruptions in Global Navigation Satellite System (GNSS) operation in these regions.

E is measure frequency of next E as prox positioned, depleting vac E to G field; mass measures @rest. Photon collapses orthogonal plane of q.s.ed space to Lorentz-invariant path "area" (∝wavelength² × periods). Magnetic field does the measuring; electric field emerges as the result?

The centre of mass of a system of three particles [The center of mass of a system of three particles](https://lnkd.in/e_fQkXqt): can be calculated using the weighted average of their positions, considering the masses of the particles. The formula is: \[ x_{\text{cm}} = \frac{m_1x_1 + m_2x_2 + m_3x_3}{m_1 + m_2 + m_3} \] \[ y_{\text{cm}} = \frac{m_1y_1 + m_2y_2 + m_3y_3}{m_1 + m_2 + m_3} \] \[ z_{\text{cm}} = \frac{m_1z_1 + m_2z_2 + m_3z_3}{m_1 + m_2 + m_3} \] Here, \((x_1, y_1, z_1)\), \((x_2, y_2, z_2)\), and \((x_3, y_3, z_3)\) are the positions of the three particles, and \(m_1\), \(m_2\), and \(m_3\) are their respective masses. The resulting values \((x_{\text{cm}}, y_{\text{cm}}, z_{\text{cm}})\) give the coordinates of the center of mass.

I am pleased to share that our recent article about determining the GNSS tropospheric delay effect with spatial analyses, entitled “Performance of spatial interpolation methods in predicting GNSS zenith total delay” has been published in Measurement (SCI-Expanded, Q1, Elsevier). For reading the article: https://lnkd.in/dyH8gkMN #GNSS_ZTD #Interpolation #Troposphere #SpatialAnalysis

This paper provides the first, fundamental analysis of #Radio #Frequency #Interference (#RFI) that #large-#scale #terrestrial #deployments introduce in different satellite sensing systems now orbiting the Earth. They develop a #geometry-#based #analysis and #extend it into a #data-#driven model which accounts for realistic propagation, building obstruction, ground reflection, for network topology with up to 10^5 nodes in more than 85 km ^2. They show that the presence of #harmful #RFI depends on several factors, including #network #load, #density and #topology, #satellite #orientation, and #building #density.----Paolo Testolina, Michele Polese, Josep Miquel Jornet, Tommaso Melodia, @Michele Zorzi More details can be found at this link: https://lnkd.in/en-jbpXd

In this paper, the authors provide the first, fundamental analysis of #Radio #Frequency #Interference (#RFI) that large-scale terrestrial deployments introduce in different satellite sensing systems now orbiting the Earth. They develop a geometry-based analysis and extend it into a data-driven model which accounts for realistic propagation, building obstruction, ground reflection, for network topology with up to 10 5 nodes in more than 85 km 2 . They show that the presence of harmful RFI depends on several factors, including network load, density and topology, satellite orientation, and building density. ---- Paolo Testolina, Michele Polese, Josep Miquel Jornet, Tommaso Melodia, Michele Zorzi More details can be found at this link: https://lnkd.in/eGxupWaU

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