Results 31 to 40 of about 134,911 (241)

Probing Transit Timing Variation and its Possible Origin with Twelve New Transits of TrES-3b [PDF]

open access: yesAstronomical Journal, 2020, Vol. 160, 47, 2020
We present twelve new transit light curves of the hot-Jupiter TrES-3b observed during $2012-2018$ to probe the transit timing variation (TTV). By combining the mid-transit times determined from these twelve transit data with those re-estimated through uniform procedure from seventy one transit data available in the literature, we derive new linear ...
arxiv   +1 more source

Signal in Space Error and Ephemeris Validity Time Evaluation of Milena and Doresa Galileo Satellites

open access: yesSensors, 2019
In August 2016, Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. If these satellites could be used, an improvement in the position accuracy would be achieved.
Umberto Robustelli   +2 more
doaj   +1 more source

Galileo Single Point Positioning Assessment Including FOC Satellites in Eccentric Orbits

open access: yesRemote Sensing, 2019
On August 2016, the Milena (E14) and Doresa (E18) satellites started to broadcast ephemeris in navigation message for testing purposes. As the Galileo constellation is not yet complete. It is very important to have two more satellites available since the
Umberto Robustelli, Giovanni Pugliano
doaj   +1 more source

Accuracy of Precise Point Positioning (PPP) with the use of different International GNSS Service (IGS) products and stochastic modelling [PDF]

open access: yesGeodesy and Cartography, 2018
This paper provides analyses of the accuracy and convergence time of the PPP method using GPS systems and different IGS products. The official IGS products: Final, Rapid and Ultra Rapid as well as MGEX products calculated by the CODE analysis centres ...
Damian Kiliszek   +2 more
doaj   +1 more source

Initial Assessment of BDS PPP-B2b Service: Precision of Orbit and Clock Corrections, and PPP Performance

open access: yesRemote Sensing, 2021
On 31 July 2020, the Beidou global navigation satellite system (BDS-3) was officially announced as being commissioned. In addition to offering global positioning, navigation, and timing (PNT) services, BDS-3 also provides precise point positioning (PPP ...
Zhixi Nie   +3 more
doaj   +1 more source

Discovery of deep eclipses in the cataclysmic variable IPHAS J051814.33+294113.0 [PDF]

open access: yes, 2018
Performing the photometric observations of the cataclysmic variable IPHAS J051814.33+294113.0, we discovered very deep eclipses. The observations were obtained over 14 nights, had a total duration of 56 hours and covered one year.
Kozhevnikov, V. P.
core   +1 more source

Comprehensive Analyses of PPP-B2b Performance in China and Surrounding Areas

open access: yesRemote Sensing, 2022
BeiDou Global Navigation Satellite System (BDS-3) provides a regional Precise Point Positioning (PPP) service, called PPP-B2b, for users in China and surrounding areas through B2b signal transmitted from its three geostationary earth orbit (GEO ...
Yan Liu, Cheng Yang, Mengni Zhang
doaj   +1 more source

Searching for Transit Timing Variations and Fitting a New Ephemeris to Transits of TrES-1 b [PDF]

open access: yes, 2022
Based on the light an exoplanet blocks from its host star as it passes in front of it during a transit, the mid-transit time can be determined. Periodic variations in mid-transit times can indicate another planet's gravitational influence. We investigate 83 transits of TrES-1 b as observed from 6-inch telescopes in the MicroObservatory robotic ...
arxiv   +1 more source

Extensive photometry of the intermediate polar V2069 Cyg (RX J2123.7+4217) [PDF]

open access: yes, 2017
To obtain the spin period of the white dwarf in the intermediate polar V2069 Cyg with high precision, we fulfilled extensive photometry. Observations were performed within 32 nights, which have a total duration of 119 hours and cover 15 months.
Kozhevnikov, V. P.
core   +1 more source

Reducing roundoff errors in numerical integration of planetary ephemeris [PDF]

open access: yes, 2023
Modern lunar-planetary ephemerides are numerically integrated on the observational timespan of more than 100 years (with the last 20 years having very precise astrometrical data). On such long timespans, not only finite difference approximation errors, but also the accumulating arithmetic roundoff errors become important because they exceed random ...
arxiv   +1 more source

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