Amir Allahvirdi-ZadehCurtin University · School of Earth and Planetary Sciences
Tracking and Positioning for Formation-Flying of Nanosatellites Using Inter-Satellite Links
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Citations since 2016
29 Research Items
I'm an expert in positioning and navigation using Global Navigation Satellite Systems (GNSS). I'm now a research associate at Curtin University working on the Australian Research Council (ARC) discovery project: "Tracking and Positioning for Formation-Flying of Nanosatellites Using Inter-Satellite Links".
January 2017 - December 2017
Geographic Organization College
- Teaching the following courses: · Route Surveying · Underground surveying · Surveying I · Surveying II
September 2005 - November 2008
Field of study
- Surveying Engineering
Making use of dual-frequency (DF) global navigation satellite system (GNSS) observations and good dynamic models, the precise orbit determination (POD) for the satellites on low earth orbits has been intensively investigated in the last decades and has achieved an accuracy of centimeters. With the rapidly increasing number of the CubeSat missions i...
For real-time precise orbit determination (POD) of low earth orbit (LEO) satellites, high-accuracy global navigation satellite system (GNSS) orbit and clock products are necessary in real time. Recently, the Japanese multi-GNSS advanced demonstration of orbit and clock analysis precise point positioning (PPP) service and the new generation of the A...
This poster has been presented at the Scientific Assembly of the International Association of Geodesy (IAG2021) conference has been held from Jun 28 to Jul 02, 2021, in Beijing, China. It is about using a new weighting model based on SIgnal-to-Noise Ratio (SNR) for the precise orbit determination of CubeSats. The related peer-review paper will be...
Precise orbit determination (POD) is the procedure for determining the orbit of a satellite with high accuracy. Compared with global navigation satellite systems (GNSS), the low Earth orbit (LEO) satellites have some different features in space, mainly due to perturbations caused by dynamic forces related to their altitudes. Methods for POD of LEO...
Global Navigation Satellite Systems’ radio occultation (GNSS-RO) provides the upper troposphere-lower stratosphere (UTLS) vertical atmospheric profiles that are complementing radiosonde and reanalysis data. Such data are employed in the numerical weather prediction (NWP) models used to forecast global weather as well as in climate change studies. T...
Signals from the emerging Low Earth Orbit (LEO) satellites from mega-constellations that broadcast internet, such as Starlink (Space X), OneWeb, Iridium etc., also known as "signals of opportunity" (SOP), can potentially aid positioning. These LEO satellites are approximately 20 times closer to Earth compared to the GNSS medium-earth orbit (MEO) sa...
Presented at FIG Congress 2022, 11-15 September 2022, Warsaw, Poland
This is the presentation of Milestone 1 (Candidacy) at Curtin University
This is the final Presentation of my PhD project.
CubeSats can be used for many space missions and Earth science applications if their orbits can be determined precisely. The Precise Orbit Determination (POD) methods are well developed for large LEO satellites during the last two decades. However, CubeSats are built from Commercial Off-The-Shelf (COTS) components and have their own characteristics...
The use of CubeSats is expanding in space and earth science applications due to the low costs of building and the possibility of launching them in a large low-earth orbits (LEO) constellation. Such constellation can serve as an augmentation system for positioning, navigation and timing. However, real-time precise orbit determination (POD) is still...
CubeSats as small Low Earth Orbiting (LEO) satellites are equipped with space-based receiver and antenna capable of tracking Global Navigation Satellite Systems (GNSS). These GNSS signals provide the possibility of precise orbit determinations (POD) of the CubeSats which is essential for different earth and space science applications. Examples of t...
What if we use software-defined radio (SDR) instead of/beside the GNSS receivers onboard the CubeSats?
There are different time systems related to Global Navigation Satellite Systems. I have introduced these systems in this chapter to Iranian students (Text in Persian)
RTKLIB is an open-source library for positioning with different methods. Precise Point Positioning is a well-known method for positioning GNSS data. In this chapter from the book "How to use RTKLIB", Precise Point Positioning by RKLIB is discussed in detail. It is in the Persian language since there is not any source for using RTKLIB in Persian. It...
RTKLIB is an open-source library for positioning with different methods. GNSS Baseline processing is one of the best methods for positioning GNSS data. In this chapter from the book "How to use RTKLIB?", GNSS Baseline processing using RTKLIB is discussed in detail. It is written in Persian since there is not any source for using RTKLIB in Persian....
RTKLIB is an open-source library for positioning with different methods. Single Point Positioning or SPP is one of the simplest methods for positioning GNSS data. In this chapter from the book "How to use RTKLIB", SPP by RKLIB is discussed in detail. It is written in Persian since there is not any source for using RTKLIB in Persian. It is published...
"Extraction atmospheric parameters of GPS data" is the title of a workshop I held for the cloud seeding staff and graduate students of the Physics department of Yazd University. It was about how to extract atmospheric parameters from GPS data and services and analyze them to calculate the Predicted Water Vapor (PWV).
GPS draconitic signal (351.6 ± 0.2 days) and its higher harmonics are observed at almost all IGS products such as position time series of IGS permanent stations. Orbital error and multipath are known as two possible sources of these signals. The effect of Earth shadow crossing of GPS satellites is another suspect for this signal. Up to now, there i...
Analysis of Radio Occultation Data with Rom SAF V8 and MATLAB and create related files. It was a part of research with the faculty members of the Physics department of Yazd university.
The Shadow toolbox is a Matlab toolbox that is written for detecting satellites in the shadow of the Earth. The input is a RINEX observation file and the output is the new and refined RINEX observation file excluding the observations of the GNSS satellites at the shadow of the Earth. http://dx.doi.org/10.6084/m9.figshare.19085546.v1
Spectral analysis of time series is an important issue in Geodesy. The main purposes of this analysis are detecting periodic behavior and the sources of these behaviors. Periodic signals and their harmonics are causes of reduced accuracy in time series analysis. Therefore these signals should be detected and removed from the results. One of these P...
"Collecting and Processing a GNSS network using GNSS receivers" was a workshop that I held at the University of Ardestan. I taught the undergrad students how to collect the required GNSS observations for network processing using GNSS receivers and then how to process them to reach the highest coordinates useful for surveying purposes.
This code get the precise ephemeris and interpolate the satellite position to the requested time.
I introduced the International GNSS Service in the internal students' seminar at the University of Isfahan: The International GNSS Service (IGS) has ensured open access, high-quality GNSS data products since 1994. These products enable access to the definitive global reference frame for scientific, educational, and commercial applications – a tre...
I introduced the International Earth Rotation and Reference Systems Service (IERS) at the University of Isfahan: The IERS was established in 1987 by the International Astronomical Union and the International Union of Geodesy and Geophysics. According to the Terms of Reference, the IERS accomplishes its mission through the following components: Tec...
I introduced the International Laser Ranging Service (ILRS), its data and products in the internal student's seminar at the University of Isfahan: Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) use short-pulse lasers and state-of-the-art optical receivers and timing electronics to measure the two-way time of flight (and hence distance)...
I introduced the international Doris Service in the internal seminars of the University of Isfahan. The Doris system is a french civil precise orbit determination and positioning system. It is based on the principle of the Doppler effect with a transmitting terrestrial beacons network and onboard instruments on the satellite's payload (antenna, ra...
In this project, I will demonstrate the process of analyzing GPS time-series data. I have used 10 years of continuous GPS measurements of four stations (ALGO, GRAZ, KOSG, and ONSA) and three different combinations of the noise component of GPS coordinate time-series, i.e., White noise, Flicker noise, and random walk noise. I use Least Squares Varia...
This code get the coordinate in ITRF and convert it to ICRF
This code get the RINEX navigation file and compute the position of satellites in ECEF
Precise Orbit Determination of low-power CubeSats using Software-Defined Radio (SDR) - onboard POD using new multi-GNSS multi-frequency receivers
POD of CubeSats based on GNSS measurements and comprehensive dynamic models and its applications on earth and space science applications. It is my PhD project which is funded by the Australian Research Council (ARC) under the discovery project: Tracking Formation-Flying of Nanosatellites Using Inter-Satellite Links (DP 190102444)