Rivista e Edizione

AHEAD OF PRINT

Volume 57 (2022): Edizione 2 (June 2022)

Volume 57 (2022): Edizione 1 (March 2022)

Volume 56 (2021): Edizione 4 (December 2021)

Volume 56 (2021): Edizione 3 (September 2021)

Volume 56 (2021): Edizione 2 (June 2021)

Volume 56 (2021): Edizione 1 (March 2021)

Volume 55 (2020): Edizione 4 (December 2020)

Volume 55 (2020): Edizione 3 (September 2020)

Volume 55 (2020): Edizione 2 (June 2020)

Volume 55 (2020): Edizione 1 (March 2020)

Volume 54 (2019): Edizione 4 (December 2019)

Volume 54 (2019): Edizione 3 (September 2019)

Volume 54 (2019): Edizione 2 (June 2019)

Volume 54 (2019): Edizione 1 (March 2019)

Volume 53 (2018): Edizione 4 (December 2018)

Volume 53 (2018): Edizione 3 (September 2018)

Volume 53 (2018): Edizione 2 (June 2018)

Volume 53 (2018): Edizione 1 (March 2018)

Volume 52 (2017): Edizione 4 (December 2017)

Volume 52 (2017): Edizione 3 (September 2017)

Volume 52 (2017): Edizione 2 (June 2017)

Volume 52 (2017): Edizione 1 (March 2017)

Volume 51 (2016): Edizione 4 (December 2016)

Volume 51 (2016): Edizione 3 (September 2016)

Volume 51 (2016): Edizione 2 (June 2016)

Volume 51 (2016): Edizione 1 (March 2016)

Volume 50 (2015): Edizione 4 (December 2015)

Volume 50 (2015): Edizione 3 (September 2015)

Volume 50 (2015): Edizione 2 (June 2015)

Volume 50 (2015): Edizione 1 (March 2015)

Volume 49 (2014): Edizione 4 (December 2014)

Volume 49 (2014): Edizione 3 (September 2014)

Volume 49 (2014): Edizione 2 (June 2014)

Volume 49 (2014): Edizione 1 (March 2014)

Volume 48 (2013): Edizione 4 (December 2013)

Volume 48 (2013): Edizione 3 (September 2013)

Volume 48 (2013): Edizione 2 (June 2013)

Volume 48 (2013): Edizione 1 (March 2013)

Volume 47 (2012): Edizione 4 (December 2012)

Volume 47 (2012): Edizione 3 (September 2012)

Volume 47 (2012): Edizione 2 (June 2012)

Volume 47 (2012): Edizione 1 (March 2012)

Volume 46 (2011): Edizione 4 (December 2011)
Proceedings of the Conference on "Satelitarne metody wyznaczania pozycji we wspólczesnej geodezji i nawigacji" held in Wroclaw, Poland, June 2-4, 2011 - Part II

Volume 46 (2011): Edizione 3 (September 2011)
Proceedings of the Conference on "Satelitarne metody wyznaczania pozycji we wspólczesnej geodezji i nawigacji" held in Wroclaw, Poland, June 2-4, 2011 - Part I

Volume 46 (2011): Edizione 2 (June 2011)

Volume 46 (2011): Edizione 1 (March 2011)

Volume 45 (2010): Edizione 4 (December 2010)

Volume 45 (2010): Edizione 3 (September 2010)

Volume 45 (2010): Edizione 2 (June 2010)
Proceedings of the IERS Workshop on EOP Combination and Prediction, Warsaw, 19-21 October 2009

Volume 45 (2010): Edizione 1 (March 2010)

Volume 44 (2009): Edizione 4 (December 2009)

Volume 44 (2009): Edizione 3 (September 2009)

Volume 44 (2009): Edizione 2 (June 2009)

Volume 44 (2009): Edizione 1 (March 2009)

Volume 43 (2008): Edizione 4 (December 2008)

Volume 43 (2008): Edizione 3 (September 2008)

Volume 43 (2008): Edizione 2 (June 2008)

Volume 43 (2008): Edizione 1 (March 2008)

Volume 42 (2007): Edizione 4 (December 2007)

Volume 42 (2007): Edizione 3 (September 2007)

Volume 42 (2007): Edizione 2 (June 2007)

Volume 42 (2007): Edizione 1 (March 2007)

Volume 41 (2006): Edizione 4 (December 2006)

Volume 41 (2006): Edizione 3 (September 2006)

Volume 41 (2006): Edizione 2 (June 2006)

Volume 41 (2006): Edizione 1 (March 2006)

Dettagli della rivista
Formato
Rivista
eISSN
2083-6104
Pubblicato per la prima volta
03 May 2007
Periodo di pubblicazione
4 volte all'anno
Lingue
Inglese

Cerca

Volume 53 (2018): Edizione 1 (March 2018)

Dettagli della rivista
Formato
Rivista
eISSN
2083-6104
Pubblicato per la prima volta
03 May 2007
Periodo di pubblicazione
4 volte all'anno
Lingue
Inglese

Cerca

4 Articoli
Accesso libero

Self-Shadowing of a Spacecraft in the Computation of Surface Forces. An Example in Planetary Geodesy

Pubblicato online: 24 Mar 2018
Pagine: 1 - 27

Astratto

Abstract

We describe in details the algorithms used in modelling the self-shadowing between spacecraft components, which appears when computing the surface forces as precisely as possible and especially when moving parts are involved. This becomes necessary in planetary geodesy inverse problems using more and more precise orbital information to derive fundamental parameters of geophysical interest. Examples are given with two Mars orbiters, which show significant improvement on drag and solar radiation pressure model multiplying factors, a prerequisite for improving in turn the determination of other global models.

Parole chiave

  • Surface forces
  • Self-shadowing
  • Polyhedral decomposition
  • Pixelation
  • Mars Planet
Accesso libero

Structural Analysis of Kufasat Using Ansys Program

Pubblicato online: 24 Mar 2018
Pagine: 29 - 35

Astratto

Abstract

The current work focuses on vibration and modal analysis of KufaSat structure using ANSYS 16 program. Three types of Aluminum alloys (5052-H32, 6061-T6 and 7075-T6) were selected for investigation of the structure under design loads. Finite element analysis (FEA) in design static load of 51 g was performed. The natural frequencies for five modes were estimated using modal analysis. In order to ensure that KufaSat could withstand with various conditions during launch, the Margin of safety was calculated. The results of deformation and Von Mises stress for linear buckling analysis were also performed. The comparison of data was done to select the optimum material for KufaSat structures.

Parole chiave

  • CubeSat
  • modal analysis
  • structure analysis
  • natural frequency
  • FEA
Accesso libero

Kinematic-PPP using Single/Dual Frequency Observations from (GPS, GLONASS and GPS/GLONASS) Constellations for Hydrography

Pubblicato online: 24 Mar 2018
Pagine: 37 - 46

Astratto

Abstract

Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.

Parole chiave

  • GPS/GLONASS
  • Precise Point Positioning
  • Kinematic
  • Single/dual
  • Hydrography
Accesso libero

A New Method for Measuring Angular Increments Based on a Tri-Axial Accelerometer and a Tri-Axial Magnetometer

Pubblicato online: 24 Mar 2018
Pagine: 47 - 53

Astratto

Abstract

Tri-axial gyroscopes used to be the only instrument used to measure the angular increments of airplanes. However, because there were no reference devices, drift and accumulation errors affected the accuracy of the estimated attitude. In this paper, we propose a novel method for measuring angular increments based on a tri-axial accelerometer and a triaxial magnetometer. Then, we mathematically proved the feasibility of the proposed method. The results of our simulation and experimental tests indicated that the proposed method accurately indicates the attitude of an airplane.

4 Articoli
Accesso libero

Self-Shadowing of a Spacecraft in the Computation of Surface Forces. An Example in Planetary Geodesy

Pubblicato online: 24 Mar 2018
Pagine: 1 - 27

Astratto

Abstract

We describe in details the algorithms used in modelling the self-shadowing between spacecraft components, which appears when computing the surface forces as precisely as possible and especially when moving parts are involved. This becomes necessary in planetary geodesy inverse problems using more and more precise orbital information to derive fundamental parameters of geophysical interest. Examples are given with two Mars orbiters, which show significant improvement on drag and solar radiation pressure model multiplying factors, a prerequisite for improving in turn the determination of other global models.

Parole chiave

  • Surface forces
  • Self-shadowing
  • Polyhedral decomposition
  • Pixelation
  • Mars Planet
Accesso libero

Structural Analysis of Kufasat Using Ansys Program

Pubblicato online: 24 Mar 2018
Pagine: 29 - 35

Astratto

Abstract

The current work focuses on vibration and modal analysis of KufaSat structure using ANSYS 16 program. Three types of Aluminum alloys (5052-H32, 6061-T6 and 7075-T6) were selected for investigation of the structure under design loads. Finite element analysis (FEA) in design static load of 51 g was performed. The natural frequencies for five modes were estimated using modal analysis. In order to ensure that KufaSat could withstand with various conditions during launch, the Margin of safety was calculated. The results of deformation and Von Mises stress for linear buckling analysis were also performed. The comparison of data was done to select the optimum material for KufaSat structures.

Parole chiave

  • CubeSat
  • modal analysis
  • structure analysis
  • natural frequency
  • FEA
Accesso libero

Kinematic-PPP using Single/Dual Frequency Observations from (GPS, GLONASS and GPS/GLONASS) Constellations for Hydrography

Pubblicato online: 24 Mar 2018
Pagine: 37 - 46

Astratto

Abstract

Global Positioning System (GPS) technology is ideally suited for inshore and offshore positioning because of its high accuracy and the short observation time required for a position fix. Precise point positioning (PPP) is a technique used for position computation with a high accuracy using a single GNSS receiver. It relies on highly accurate satellite position and clock data that can be acquired from different sources such as the International GNSS Service (IGS). PPP precision varies based on positioning technique (static or kinematic), observations type (single or dual frequency) and the duration of observations among other factors. PPP offers comparable accuracy to differential GPS with safe in cost and time. For many years, PPP users depended on GPS (American system) which considered the solely reliable system. GLONASS's contribution in PPP techniques was limited due to fail in maintaining full constellation. Yet, GLONASS limited observations could be integrated into GPS-based PPP to improve availability and precision. As GLONASS reached its full constellation early 2013, there is a wide interest in PPP systems based on GLONASS only and independent of GPS. This paper investigates the performance of kinematic PPP solution for the hydrographic applications in the Nile river (Aswan, Egypt) based on GPS, GLONASS and GPS/GLONASS constellations. The study investigates also the effect of using two different observation types; single-frequency and dual frequency observations from the tested constellations.

Parole chiave

  • GPS/GLONASS
  • Precise Point Positioning
  • Kinematic
  • Single/dual
  • Hydrography
Accesso libero

A New Method for Measuring Angular Increments Based on a Tri-Axial Accelerometer and a Tri-Axial Magnetometer

Pubblicato online: 24 Mar 2018
Pagine: 47 - 53

Astratto

Abstract

Tri-axial gyroscopes used to be the only instrument used to measure the angular increments of airplanes. However, because there were no reference devices, drift and accumulation errors affected the accuracy of the estimated attitude. In this paper, we propose a novel method for measuring angular increments based on a tri-axial accelerometer and a triaxial magnetometer. Then, we mathematically proved the feasibility of the proposed method. The results of our simulation and experimental tests indicated that the proposed method accurately indicates the attitude of an airplane.

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