Results 21 to 30 of about 22,697 (311)

Uncertainty Analysis of the Short-Arc Initial Orbit Determination

IEEE Access, 2020
The solution of the short-arc angles-only orbit determination problem has large uncertainty because the topocentric range is not observable. For a certain angular observation tracklet with measurement noise, there exist numerous potential orbits, all of ...
Xuefeng Tao, Zhi Li, Qiuwu Gong, Yasheng Zhang, Ping Jiang   +4 more
doaj   +1 more source

Sensitivity of the Gravity Model and Orbital Frame for On-board Real-Time Orbit Determination: Operational Results of GPS-12 GPS Receiver

Remote Sensing, 2019
This paper describes the sensitivity of both the orbital frame domain selection and the gravity model on the performance of on-board real-time orbit determination.
Eunhyouek Kim, Seungyeop Han, Amer Mohammad Al Sayegh   +2 more
doaj   +1 more source

Correction Method for the Observed Global Navigation Satellite System Ultra-Rapid Orbit Based on Dilution of Precision Values

Sensors, 2018
For ultra-rapid orbits provided by the Global Navigation Satellite System (GNSS), the key parameters, accuracy and timeliness, must be taken into consideration in real-time and near real-time applications.
Qianxin Wang, Chao Hu, Ya Mao
doaj   +1 more source

Research on the Rotational Correction of Distributed Autonomous Orbit Determination in the Satellite Navigation Constellation

Remote Sensing, 2022
The autonomous orbit determination of the navigation constellation uses only bidirectional ranging data of the inter-satellite link for data processing.
Wei Zhou, Hongliang Cai, Ziqiang Li, Chengpan Tang, Xiaogong Hu, Wanke Liu   +5 more
doaj   +1 more source

Non-Cooperative LEO Satellite Orbit Determination Using Single Station for Space-Based Opportunistic Positioning

Remote Sensing
Space-based opportunistic positioning is a crucial component of resilient positioning, navigation, and timing (PNT) systems, and it requires the acquisition of orbit information for non-cooperative low Earth orbit (LEO) satellites.
Ruofan Deng, Honglei Qin, Yu Zhang
doaj   +1 more source

Asteroid impact monitoring [PDF]

Serbian Astronomical Journal, 2006
Some asteroids and comets with Earth-crossing orbit may impact our planet, thus we need to be able to identify the cases which could have a dangerous close approach within a century.
Milani A.
doaj   +1 more source

Direct Initial Orbit Determination

IEEE Transactions on Aerospace and Electronic Systems
Initial orbit determination (IOD) is an important early step in the processing chain that makes sense of and reconciles the multiple optical observations of a resident space object. IOD methods generally operate on line-of-sight (LOS) vectors extracted from images of the object, hence the LOS vectors can be seen as discrete point samples of the raw ...
Chee-Kheng Chng, Trent Jansen-Sturgeon, Timothy Payne, Tat-Jun Chin   +3 more
openaire   +2 more sources

Determining Orbits for the Milky Way’s Dwarfs [PDF]

AIP Conference Proceedings, 2010
We calculate orbits for the Milky Way dwarf galaxies with proper motions, and compare these to subhalo orbits in a high resolution cosmological simulation. We use the simulation data to assess how well orbits may be recovered in the face of measurement errors, a time varying triaxial gravitational potential, and satellite-satellite interactions.
H. Lux, J. I. Read, G. Lake, Victor P. Debattista, C. C. Popescu   +4 more
openaire   +7 more sources

Clinical and Biological Features of Response in Resistant Neuroblastoma to 131I‐Metaiodobenzylguanidine Radiotherapy in the Anti‐GD2 Immunotherapy Era

Pediatric Blood &Cancer, EarlyView.
ABSTRACT Background 131I‐metaiodobenzylguanidine (131I‐MIBG) radiotherapy is a key treatment for relapsed and refractory (R/R) neuroblastoma (NB). Patients with R/R disease treated in the modern era are increasingly exposed to anti‐GD2 immunotherapy, which exerts selective pressure and may modify both tumor cell state and microenvironment.
Benjamin J. Lerman, Katherine K. Matthay, Fabienne Hollinger, Catriona Black, Ann A. Lazar, Miguel Pampaloni, Steven G. DuBois, Kieuhoa T. Vo   +7 more
wiley   +1 more source

Perturbed initial orbit determination

Astrodynamics
An algorithm for robust initial orbit determination (IOD) under perturbed orbital dynamics is presented. By leveraging map inversion techniques defined in the algebra of Taylor polynomials, this tool returns a highly accurate solution to the IOD problem and estimates a range centered on the aforementioned solution in which the true orbit should lie. To
Alberto Fossà, Matteo Losacco, Roberto Armellin   +2 more
openaire   +2 more sources