14 research outputs found
An artificially generated atmosphere near a lunar base
We discuss the formation of an artificial atmosphere generated by vigorous lunar base activity in this paper. We developed an analytical, steady-state model for a lunar atmosphere based upon previous investigations of the Moon's atmosphere from Apollo. Constant gas-injection rates, ballistic trajectories, and a Maxwellian particle distribution for an oxygen-like gas are assumed. Even for the extreme case of continuous He-3 mining of the lunar regolith, we find that the lunar atmosphere would not significantly degrade astronomical observations beyond about 10 km from the mining operation
Martian Ionosphere Electron Density Prediction Using Bagged Trees
The availability of Martian atmospheric data provided by several Martian
missions broadened the opportunity to investigate and study the conditions of
the Martian ionosphere. As such, ionospheric models play a crucial part in
improving our understanding of ionospheric behavior in response to different
spatial, temporal, and space weather conditions. This work represents an
initial attempt to construct an electron density prediction model of the
Martian ionosphere using machine learning. The model targets the ionosphere at
solar zenith ranging from 70 to 90 degrees, and as such only utilizes
observations from the Mars Global Surveyor mission. The performance of
different machine learning methods was compared in terms of root mean square
error, coefficient of determination, and mean absolute error. The bagged
regression trees method performed best out of all the evaluated methods.
Furthermore, the optimized bagged regression trees model outperformed other
Martian ionosphere models from the literature (MIRI and NeMars) in finding the
peak electron density value, and the peak density height in terms of
root-mean-square error and mean absolute error.Comment: The peer-reviewed paper is available at:
https://doi.org/10.1109/ICECTA57148.2022.999050
Amplitude Scintillation Forecasting Using Bagged Trees
Electron density irregularities present within the ionosphere induce
significant fluctuations in global navigation satellite system (GNSS) signals.
Fluctuations in signal power are referred to as amplitude scintillation and can
be monitored through the S4 index. Forecasting the severity of amplitude
scintillation based on historical S4 index data is beneficial when real-time
data is unavailable. In this work, we study the possibility of using historical
data from a single GPS scintillation monitoring receiver to train a machine
learning (ML) model to forecast the severity of amplitude scintillation, either
weak, moderate, or severe, with respect to temporal and spatial parameters. Six
different ML models were evaluated and the bagged trees model was the most
accurate among them, achieving a forecasting accuracy of using a
balanced dataset, and using an imbalanced dataset.Comment: This paper was presented at IGARSS 2022, Kuala Lumpur, Malaysia. doi:
10.1109/IGARSS46834.2022.988338
Space technology capacity building in support of SDG 2030 through CubeSat SharjahSat-l
The SHARJAH-SAT-1 would be the first CubeSat mission to be developed by the Sharjah Academy for Astronomy, Space Sciences, and Technology (SAASST)students and researchers, with the aim of not only designing, fabricating, testing & launching the CubeSat itself, but also building the capacities and expertise for future SAASST CubeSat missions as well. For the project, SAASST is working in close collaboration with an experienced international partner, the Istanbul Technical University, Space Systems Design and Test Laboratory which has already developed and launched 5 CubeSats into low earth orbit. Overall, the project, puts the human capacity development in its center, in support of UN SDG 2030 for an equal world
The high energy astrophysics group in the light of SHARJAH-SAT-1 and future projects
The newly formed High Energy Astrophysics (HEA) Group at the Sharjah Academy of Astronomy, Space Science, and Technology (SAASST) and the University of Sharjah (UoS) focuses on the accretion processes onto compact objects, mainly on neutron stars and black holes, across the electromagnetic spectrum. Our research lies on observations of Galactic black holes as well as accreting neutron stars in both high and low mass X-ray binary systems. An extensive research programme on accreting compact objects utilizes an armada of X-ray observsatories (e.g., XMM-Newton/ESA, Chandra/NASA, INTEGRAL/ESA, Neil Gehrels Swift Observatory/NASA, NuStar/NASA, etc) alongside major ground-based facilities such as the European's Southen Observatory (ESO), Very Large Telescope (VLT) and smaller 1m-class telescopes. Besides the observational part, in our research group we are using an advanced inventory of state-of-the-art tools such as (magneto)hydrodynamical and General-Relativistic (magneto)hydrodynamical simulations, alongside radiative transfer and ray-tracing tools to further study and shed light onto the elusive nature of these accreting compact objects and their surrounding environment. Moreover, this group will provide a direct science exploitation of the forthcoming 3U CubeSat SHARJAHSAT-1. The primary science payload on board is the iXRD (developed by Sabanci University) which will provide an improved version of XRD on board BeEagleSat. The leading technology behind iXRD is a CdZnTe-based crystal, operational in the hard X-rays regime, between 20 and 200 keV energy range. The target spectral resolution of the detector is 6 keV at 60 keV. Its' main science goal of the mission is long term monitoring of the brightest galactic X-ray sources, transient and persistent. Black holes and pulsars can emit radiation up to a few 100 keVs making them ideal targets. In addition, hard X-ray spectra from solar flare and coronal holes will be studied. Transient bright events, such as gamma-ray burst (GRB) and magnetar bursts will be studied as well as target of opportunities (TOO). Currently the project is at the Critical Design Review (CDR) level and the anticipated launch is planned for early-to-mid 2021
Unification of Fanaroff-Riley II Radio Sources with 0.1 < z < 2.0 – 8.4 GHz VLA Observations of 15 Sources – Final Sample
Human and technological capacity building through the Sharjah-Sat-1 CubeSat project
Sharjah-Sat-1 is 3U+ CubeSat, carrying a primary payload consisting of an X-ray detector to study bright X-ray sources in our Galaxy and a dual camera system as a secondary, remote-sensing application payload. It is the first small satellite mission of the Sharjah Academy for Astronomy, Space Sciences, and Technology (SAASST) and the University of Sharjah (UoS), developed in close collaboration with Istanbul Technical University Space Systems Design and Test Laboratory (ITU-SSDTL) and Sabanci University (SU). Small satellites, especially CubeSat standard, have greatly interested universities and educational establishments due to their lower costs and shorter development time. This makes them ideal for engaging students in the design, testing, and operation of satellite missions and offers a unique first-hand experience in the space industry. The Sharjah-Sat-1 project has provided an essential basis for theoretical and hands-on knowledge of space technologies. This included various extensive workshops for the team of undergraduate students involved and public outreach programs on the topics of satellites and space systems. Additionally, the project has created a solid infrastructure at the Academy to develop further CubeSat missions in the future. Throughout the mission duration, the CubeSat laboratory at SAASST has been expanding and building the necessary facilities that are vital for its success. This includes the high-performance Workstation loaded with the required software to design, simulate and analyze the mission in the space environment, the cleanroom (ISO6 certified) to integrate and test the satellite subsystems, and the ground station (VHF/UHF) needed to communicate with CubeSat once it is in orbit. Furthermore, the participating students have been trained on how to use the software and the operation of the ground station in the scope of the Sharjah-Sat-1 mission. Ultimately, the human and technological capacities the project has built and all experience gained will certainly be transferred to future projects
SharjahSat-1 space-to-ground telecommunication operations
SharjahSat-1 is a collaborative research project by the Sharjah Academy for Astronomy, Space Science, and Technology (SAASST), University of Sharjah (UoS), Istanbul Technical University Space Systems Design and Test Laboratory (ITU-SSDTL), and Sabanci University (SU). The 3U+ CubeSat will host an improved X-ray Detector (iXRD) as the primary payload and a secondary payload system of a dual optical camera system. The X-ray detector's objective is to detect hard X-rays from very bright X-ray sources, and to study the solar coronal holes, whereas the camera system will provide a low-resolution remote sensing application. Although SharjahSat-1 would be the first CubeSat mission to be developed by SAASST and UoS, it aims to extend the experience for the following CubeSat missions. The anticipated launch date of the CubeSat is by the fourth quarter of 2022. Many parameters such as emission patterns, data rates, modulation schemes, and the dynamics of the satellites affect the completion of the communication links between the CubeSat and the ground station. Thus, it is crucial to consider all major and minor parameters while designing and performing telecommunication operations. SharjahSat-1 host a transmitter and a transceiver and their antennas to communicate the data from the payloads and telemetry through different frequency bands. It will perform these operations through S-band and VHF/UHF frequency ranges due to its payloads requirement of high data rates. Moreover, SAASST is equipped with an S-Band, a full-duplex VHF/UHF Ground Station, and a Software Defined Radio (SDR) ground station transceiver to fulfill such mission requirements and assure its success. Furthermore, a custom-console software was developed to control SharjahSat-1 while it is in orbit by sending commands to execute diverse types of operations that will directly affect the practicality of mission objectives. This paper comprises SharjahSat-1 communication subsystem design significance due to the requirements of the payloads. Then it will put forward the composition of the full-fledged SAASST Ground Segment equipped with technologically advanced hardware components that allow full automation during operations as it is remotely controlled. Finally, it will describe the developed custom-console software that aids the mission's operations to formulate a comprehensive End-to-End communication operations process