A Sensitivity Study of POD Using Dual-Frequency GPS for CubeSats Data Limitation and Resources

Wang, Kan; Allahvirdi-Zadeh, Amir; El‐Mowafy, Ahmed; Gross, Jason N.

doi:10.3390/rs12132107

Cited by 19 publications

(8 citation statements)

References 46 publications

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“…For LEO POD, the least-squares adjustment is performed using 24 h of GPS observations with a sampling interval of 30 s, which is sufficient for LEO POD (Wang et al 2020). The dynamic models used for numerical integration are summarized in Table 1.…”

Section: Processing Strategymentioning

confidence: 99%

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Integrity monitoring for precise orbit determination of LEO satellites

2021

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Due to an increasing requirement for high accuracy orbital information for low Earth orbit (LEO) satellites, precise orbit determination (POD) of LEO satellites is a topic of growing interest. To assure the safety and reliability of the applications requiring high accuracy LEO orbits in near-real-time, integrity monitoring (IM) is an essential operation of the POD process. In this contribution, the IM strategy for LEO POD in both the kinematic and reduced-dynamic modes is investigated. The overbounding parameters of the signal-in-space range error are investigated for the GPS products provided by the International GNSS Service’s Real-Time Service and the Multi-GNSS Advanced Demonstration of Orbit and Clock Analysis service. Benefiting from the dynamic models used and the improved model strength, the test results based on the data of the LEO satellite GRACE FO-1 show that the average-case mean protection levels (PLs) can be reduced from about 3–4 m in the kinematic mode to about 1 m in the reduced-dynamic mode in the radial, along-track and cross-track directions. The overbounding mean values of the SISRE play the dominant role in the final PLs. In the reduced-dynamic mode and average-case projection, the IM availabilities reach above 99% in the radial, along-track and cross-track directions with the alert limit (AL) set to 2 m. The values are still above 98% with the AL set to 4 m, when the duty cycle of tracking is reduced to 40%, e.g., in the case of power limits for miniature satellites such as CubeSats.

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Section: Processing Strategymentioning

confidence: 99%

“…The reduced data decreases the model strength and the precision of the estimated orbital parameters. However, in the reduced-dynamic mode the orbital positions and PLs can still be computed over the entire period, benefiting from the dynamic model and numerical integration (Wang et al 2020).…”

Section: Pls With Different Duty Cyclesmentioning

confidence: 99%

Integrity monitoring for precise orbit determination of LEO satellites

2021

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“…The processing details and the dynamic models used in the processing are summarized in Table 3 . An observation sampling interval of 30 s was chosen for faster processing, where the resulted orbital accuracy should not differ much compared to the case when a shorter sampling interval of, e.g., 10 or 20 s was used [ 19 ]. The prediction here refers to the orbital extrapolation.…”

Section: Processing Proceduresmentioning

confidence: 99%

Proposed Orbital Products for Positioning Using Mega-Constellation LEO Satellites

Wang

El‐Mowafy

2020

Sensors

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With thousands of low Earth orbit (LEO) satellites to be launched in the near future, LEO mega-constellations are supposed to significantly change the positioning and navigation service for ground users. The goal of this contribution is to suggest and discuss the feasibility of possible procedures to generate the LEO orbital products at two accuracy levels to facilitate different positioning methods—i.e., Level A orbits with meter-level accuracy as LEO-specific broadcast ephemeris, and Level B orbits with an accuracy of centimeters as polynomial corrections based on Level A orbits. Real data of the LEO satellite GRACE FO-1 are used for analyzing the error budgets. For the Level A products, compared to the orbital user range errors (OUREs) of a few centimeters introduced by the ephemeris fitting, it was found that the orbital prediction errors play the dominant role in the total error budget—i.e., at around 0.1, 0.2 and 1 m for prediction intervals of 1, 2 and 6 h, respectively. For the Level B products, the predicted orbits within a short period of up to 60 s have an OURE of a few centimeters, while the polynomial fitting OUREs can be reduced by a few millimeters when increasing the polynomial degree from one to two.

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“…Some companies have deployed cubesats for RO ionospheric sounding successfully [36], [37], despite initial problems due to size and power (e.g. duty cycling impact, see for instance [38]).…”

Section: Introductionmentioning

confidence: 99%

Systematic Detection of Anomalous Ionospheric Perturbations Above LEOs From GNSS POD Data Including Possible Tsunami Signatures

Yang

Hernández‐Pajares

Jarmołowski

et al. 2022

IEEE Trans. Geosci. Remote Sensing

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In this paper we show the capability of Global Navigation Satellite System (GNSS) Precise Orbit Determination (POD) Low Earth Orbiter (LEO) data to detect anomalous ionospheric disturbances in the spectral range of the signals associated to earthquakes and tsunamis, applied to two of these events in Papua New Guinea (PNG) and Solomon Islands during 2016. This is achieved thanks to the new PIES approach (POD-GNSS LEO Detrended Ionospheric Electron Content Significant Deviations). The significance of such ionospheric signals above the Swarm LEOs is confirmed with different types of independent data: in-situ electron density measurements provided by the Langmuir Probe (LP) on board Swarm LEOs, DORIS and ground-based GNSS co-located measurements, as it is described in the paper. In this way we conclude the possible detection of the tsunami related ionospheric gravity wave in PNG 2016 event, consistent with the most-recent theory which shows that a tsunami (which is localized in space and time) excites a spectrum of gravity waves, some of which have faster horizontal phase speeds than the tsunami. We believe that this work shows as well the feasibility of a future potential monitoring system of ionospheric disturbances, to be made possible by hundreds of cubesats with POD GNSS receivers among other appropriate sensors, and supported for real-time or near real-time confir-

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A Sensitivity Study of POD Using Dual-Frequency GPS for CubeSats Data Limitation and Resources

Cited by 19 publications

References 46 publications

Integrity monitoring for precise orbit determination of LEO satellites

Integrity monitoring for precise orbit determination of LEO satellites

Proposed Orbital Products for Positioning Using Mega-Constellation LEO Satellites

Systematic Detection of Anomalous Ionospheric Perturbations Above LEOs From GNSS POD Data Including Possible Tsunami Signatures

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