Results 11 to 20 of about 169 (129)

Precise disciplining of a chip-scale atomic clock using PPP with broadcast ephemerides [PDF]

open access: yesGPS Solutions, 2023
AbstractOver the last decade, chip-scale atomic clocks (CSACs) have emerged as stable time and frequency references with small size, weight, and power (SWaP). While the short-term stability of these devices clearly outperforms other oscillators with similar power consumption, their stability over longer time intervals is notably limited by frequency ...
Oliver Montenbruck, Florian Kunzi
exaly   +3 more sources

ASSESSING EFFICIENCY OF GPS EPHEMERIDES IN DIFFERENT REGION USING PRECISE POINT POSITIONING [PDF]

open access: yesThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2023
Precise Point Positioning (PPP) is a technique that process Global Positioning System (GPS) observation that can achieve sub-decimetre accuracy. Precise ephemerides that contain satellite clock and position plays a vital role in minimising orbital and ...
H. S. Lee   +3 more
doaj   +1 more source

Effect of using different satellite ephemerides on GPS PPP and post processing techniques

open access: yesGeodesy and Cartography, 2021
The orbital error is one of the errors in GPS which affect the accuracy of GPS positioning. In this research GPS broadcast, ultra-rapid, rapid and precise satellite ephemerides are used for processing different baseline lengths among some CORS stations ...
Khaled Mahmoud Abdel Aziz   +1 more
doaj   +1 more source

Mobile laser scanning elevation data accuracy in closed and partially open sky area

open access: yesGeodesy and Cartography, 2021
Mobile laser scanning is being used more often in Estonia and abroad to obtain geospatial information. As the system is still new and being upgraded, different methods are being used to find out how accurately the mobile laser scanner can measure in ...
Gerly Annok, Valdar Tammin, Natalja Liba
doaj   +1 more source

Implementation of the variation of the luni-solar acceleration into GLONASS orbit calculus [PDF]

open access: yesGeodetski Vestnik, 2021
In the differential equation system describes the motion of GLONASS satellites (rus. Globalnaya Navigazionnaya Sputnikovaya Sistema, or Global Navigation Satellite System ), the acceleration caused by the luni-solar traction is often taken as a constant ...
Sid Ahmed Medjahed   +3 more
doaj   +1 more source

Orbital Elements Ephemerides and Interfaces Design of LEO Satellites [PDF]

open access: yesJournal of Geodesy and Geoinformation Science, 2019
Low earth orbit satellites, with unique advantages, are prosperous types of navigation augmentation satellites for the GNSS satellites constellations. The broadcast ephemeris element needs to be designed as an important index of the augmented LEOs.
Shanchuan FANG,Lan DU,Yunpeng GAO,Peiyuan ZHOU,Zejun LIU
doaj   +1 more source

PRELIMINARY ANALYSES OF BEIDOU SIGNAL-IN-SPACE ANOMALY SINCE 2013 [PDF]

open access: yesThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2016
As BeiDou navigation system has been operational since December 2012. There is an increasing desire to use multiple constellation to improve positioning performance. The signal-in-space (SIS) anomaly caused by the ground control and the space vehicle is
Y. Wu, J. Ren, W. Liu, W. Liu
doaj   +1 more source

Satellite Availability and Service Performance Evaluation for Next-Generation GNSS, RNSS and LEO Augmentation Constellation

open access: yesRemote Sensing, 2021
Positioning accuracy is affected by the combined effect of user range errors and the geometric distribution of satellites. Dilution of precision (DOP) is defined as the geometric strength of visible satellites.
Haomeng Cui, Shoujian Zhang
doaj   +1 more source

Real-time precise measurements of ocean surface waves using GNSS variometric approach

open access: yesInternational Journal of Applied Earth Observations and Geoinformation, 2022
The global navigation satellite system (GNSS) wave buoys currently in use can measure ocean surface waves but have major drawbacks regarding their real-time high-precision application due to the communication burden and high differential correction ...
Yang Liu   +7 more
doaj   +1 more source

Sub-Decimeter Onboard Orbit Determination of LEO Satellites Using SSR Corrections: A Galileo-Based Case Study for the Sentinel-6A Satellite

open access: yesRemote Sensing, 2022
In GNSS-based navigation onboard Low Earth Orbit (LEO) satellites, typical accuracy requirements are 10 cm and 0.1 mm/s for 3D position and velocity, respectively.
Francesco Darugna   +4 more
doaj   +1 more source

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