Abdelrahim Ruby

21 Questions 54 Answers 0 Followers

Questions related from Abdelrahim Ruby

What is the influence of the satellite's attitude on the accuracy of the instantaneous range?

Assume I have the coordinates of satellite xs (t) and ground station xg (t) in the International Terrestrial Reference Frame (ITRF). Also, the attitude of satellites in the form of quaternions is...

11 December 2023 8,787 0 View

How can the divergence between the transmitting laser and the retroreflectors be minimized in Satellite Laser Ranging (SLR)?

The general characteristics of Satellite Laser Ranging (SLR): The photons returning are usually fewer because the transmitting laser and retroreflectors both have a divergence. This means that the...

11 May 2023 9,250 10 View

Is the frequency drift value constant, linear, or nonlinear variation in the case of an atomic clock?

In an atomic clock: instability in the oscillator and environmental changes can cause frequency drift, although it is often hard to identify between drift and oscillator aging. So, is the...

17 March 2023 2,749 4 View

How to apply relativistic effects, when synchronizing a satellite clock with a clock at rest on the surface of the rotating Earth?

In the relativistic theory for synchronization between satellite and ground atomic clocks, the major sources of relativistic effects are relative motion between the two clocks and the movement of...

19 March 2021 1,587 5 View

How to reduce the noise of the space oscillator in TWSTFT?

In common view mode, the ground to ground time transfer by Two- Way satellite Time and Frequency Transfer (TWSTFT), What are the different models which reduces the noise of the space clocks?

30 June 2020 7,621 4 View

Is there a simple method to use pslegend (GMT) to create a legend for 2-D plot?

I am new for Generic Mapping Tool (GMT), but I would like to work through a few simple examples of generating legends (ie. multiple points or lines plotted on a single figure using psxy). In the...

27 April 2018 8,422 3 View

What is the difference between SRTM90m v 4.1 and SRTM30_Plus v10?

The SRTM90m v4.1 is a digital elevation model with a resolution of 90 metres (3'' Arc-Sec) and available through the CGIAR-CSI data centre web page at...

31 January 2018 8,807 8 View

How to use high precise geoid for mineral exploration?

Recently, many scientific applications such as: In geology, the inversion of the geoid is used for Petroleum Exploration. I am looking for studies and research in this field

02 January 2018 2,661 4 View

What are the different between the three dedicated gravity fields mapping mission, (CHAMP, GRACE and GOCE), in geoid modeling?

I am looking for a research about: Comparison between the three dedicated gravity fields mapping mission, [CHAMP (1996), GRACE (2002) and GOCE (2009)], in geoid modeling (when using the...

02 April 2017 7,769 3 View

Why use the coefficient C2,0 (only) to Conversion between different permanent tide systems in any spherical harmonics geopotential model?

Conversion between different permanent tide systems involves either modifying one spherical harmonic coefficient or adding a zonally uniform correction to the geoid undulations. More information...

20 March 2017 4,168 5 View

Can any one help me to find the first intersection point between two line by matlab?

i need to find the value (on x-axis ) of the first intersection point between two line by matlab See attached for (data ,code and output )

06 September 2016 6,781 6 View

How can I get this references?

As possible, any researcher helps me to getting this research G. WEBER, 1984: Hochauflösende mittlere Freiluftanomalien und gravimetrische Lotabweichungen für Europa. Wissenschaftliche Arbeiten...

01 July 2016 4,951 1 View

What are the different sites for downloading best resolution (below 20 m) for free remote sensing imagery?

I am looking for satellite image used for academic purposes

11 November 2015 6,844 8 View

What are different sites for downloading Digital Elevation Models (DEMs) (of land and sea-floor elevations)?

I’m looking for a Digital Elevation Models for Relief (topographic + bathymetric) with different resolution of the gridded data varies from true 30-Arc sec and 1-Arc sec

22 September 2015 3,150 13 View

What is the difference between gravity anomaly and gravity disturbance?

I would like to convert Observed (or measured) Gravity (g) on the earth surface into gravity anomaly and gravity disturbance

03 August 2015 8,607 5 View

How to use spherical harmonic expansions for Earth's topography to extract (DTM’s)?

HI, all I want to get the program to extract Digital terrain models (DTM’s) or Digital height models (DHM’s) for a certain area from Global Gravity Field Models related to Topography For example ...

13 July 2015 6,721 11 View

How development Global Gravity Field Models like EGM96?

I have some questions about Global Gravity Field Models (ICGFM).Where How to Calculate Coefficients of this model? I.e. I need the program to compute spherical harmonic analysis of EGM model.

12 April 2015 3,531 11 View

Are there any programs to convert observed gravity into normal gravity value on the surface of the ellipsoid (WGS84) and free air anomaly?

I am looking for a program to compute into Theoretical (Normal) Gravity (γ) value on the surface of the ellipsoid (WGS84) and Free-Air Anomaly (Δgf) with knowing Observed (or measured) Gravity (g)...

20 March 2015 5,802 5 View

What are the programs that work for gravity model evaluation ?

I would like to subtract the contribution from a global gravity model (here EGM96 and EGM08) from the free-air anomalies (Δg) . And the height anomalies (ζ) . Can you suggest a program to do this?

20 March 2015 5,139 2 View

Is there a program converted the EGM96 ellipsoidal harmonic coefficient set to their spherical harmonic coefficient counterpart?

I'm looking for a program to converted ellipsoidal to spherical harmonic coefficient .

13 March 2015 148 2 View

How can I run the program “ harmonic_synth_v02”?

During compilation it generates a number of warning messages that causes compilation to fail at the position indicated below. error messages from...

06 February 2015 5,055 2 View