LEO augmented precise point positioning using real observations from two CENTISPACE™ experimental satellites

Li, Wenwen; Yang, Qiangwen; Du, Xiaodong; Li, Min; Zhao, Qile; Yang, Long; Qin, Yanan; Chang, Chuntao; Wang, Yubin; Qin, Geer

doi:10.1007/s10291-023-01589-0

Cited by 11 publications

(2 citation statements)

References 37 publications

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“…quantity of both currently operational and planned LEO satellites has surged, reaching tens of thousands. The increasing number of LEO satellites has brought opportunities for their use in augmentation of traditional Global Navigation Satellite System (GNSS)-based positioning, navigation, and timing [4][5][6]. Benefiting from the lower altitudes and higher speeds of LEO satellites, the augmentation of the GNSS by LEO satellites has numerous advantages, including providing hundreds to thousands of times stronger signal strength than the GNSS satellites [7], the more rapid convergence time of precise point positioning (PPP) and the PPP-Real-Time Kinematic positioning due to the rapid geometry change [8][9][10].…”

Section: Introductionmentioning

confidence: 99%

PCO and hardware delay calibration for LEO satellite antenna downlinking navigation signals

Liu,

Wang,

El-Mowafy

et al. 2024

Meas. Sci. Technol.

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Augmentation of the GNSS by Low Earth Orbit (LEO) satellites is a promising approach benefiting from the advantages of LEO satellites. This, however, requires errors and biases in the satellite downlink navigation signals to be calibrated, modeled, or eliminated. This contribution introduces an approach for in-orbit calibration of the Phase Center Offsets (PCOs) and code hardware delays of the LEO downlink navigation signal transmitter/antenna. Using the satellite geometries of Sentinel-3B and Sentinel-6A as examples, the study analyzed the formal precision and bias influences for potential downlink antenna PCOs and hardware delays of LEO satellites under different ground network distributions, and processing periods. It was found that increasing the number of tracking stations and processing periods can improve the formal precision of PCOs and hardware delay. Less than 3.5 mm and 3 cm, respectively, can be achieved with 10 stations and 6 processing days. The bias projections of the real-time LEO satellite orbital and clock errors can reach below 3 mm in such a case. For near-polar LEO satellites, stations in polar areas are essential for strengthening the observation model.

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Section: Introductionmentioning

confidence: 99%

PCO and hardware delay calibration for LEO satellite antenna downlinking navigation signals

Liu,

Wang,

El-Mowafy

et al. 2024

Meas. Sci. Technol.

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show abstract

“…In recent years, due to the unique advantages of orbital characteristics and signal strength, augmentation with Low Earth Orbit (LEO) satellites has gained attention and favor in the global satellite navigation field, promising to be an incremental development in the next generation of satellite navigation systems. Worldwide, there is the active implementation and deployment of LEO satellite constellation plans, such as Musk's Starlink [2], the OneWeb [3], the Iridium [4], the Xona's Pulsar of the United States [5], the Kepler system of Germany [6], and the Centispace [7], Hongyan and Hongyun [8] of satellite clocks by integrating ground observations from specific regions with onboard observations from LEO satellites. Without using a ground network, the kinematic clock estimation achieved a precision of over 0.3 ns using GNSS products, while incorporating a simulated ground network improved the clock precision to 0.15 ns [23].…”

Section: Introductionmentioning

confidence: 99%

Real-Time LEO Satellite Clocks Based on Near-Real-Time Clock Determination with Ultra-Short-Term Prediction

Wu,

Wang,

Wang

et al. 2024

Remote Sensing

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The utilization of Low Earth Orbit (LEO) satellites is anticipated to augment various aspects of traditional GNSS-based Positioning, Navigation, and Timing (PNT) services. While the LEO satellite orbital products can nowadays be produced with rather high accuracy in real-time of a few centimeters, the precision of the LEO satellite clock products that can be achieved in real-time is less studied. The latter, however, plays an essential role in the LEO-augmented positioning and timing performances. In real-time, the users eventually use the predicted LEO satellite clocks, with their precision determined by both the near-real-time clock precision and the prediction time needed to match the time window for real-time applications, i.e., the precision loss during the prediction phase. In this study, a real-time LEO satellite clock determination method, consisting of near-real-time clock determination with ultra-short-term clock prediction is proposed and implemented. The principles and strategies of this method are discussed in detail. The proposed method utilized Kalman-filter-based processing, but supports restarts at pre-defined times, thus hampering continuous bias propagation and accumulation from ancient epochs. Based on the method, using Sentinel-3B GNSS observations and the real-time GNSS products from the National Center for Space Studies (CNES) in France, the near-real-time LEO satellite clocks can reach a precision of 0.2 to 0.3 ns, and the precision loss during the prediction phase is within 0.07 ns for a prediction time window from 30 to 90 s. This results in a total error budget in the real-time LEO satellite clocks of about 0.3 ns.

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The topside global broadcast ionospheric delay correction model for future LEO navigation augmentation

Yang,

Guo,

Tang

et al. 2024

J Geod

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LEO augmented precise point positioning using real observations from two CENTISPACE™ experimental satellites

Cited by 11 publications

References 37 publications

PCO and hardware delay calibration for LEO satellite antenna downlinking navigation signals

PCO and hardware delay calibration for LEO satellite antenna downlinking navigation signals

Real-Time LEO Satellite Clocks Based on Near-Real-Time Clock Determination with Ultra-Short-Term Prediction

The topside global broadcast ionospheric delay correction model for future LEO navigation augmentation

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