Use of two traveling GPS receivers for a relative calibration campaign among European laboratories

Uhrich, Pierre; Rovera, Daniele; Chupin, Baptiste; Galindo, J.; Esteban, H.; Jaldehag, Kenneth; Rieck, Carsten; Bauch, A.; Polewka, T.; Cerretto, Giancarlo; Fantino, G.; Piriz, R.

doi:10.1109/fcs.2015.7138927

Cited by 4 publications

(6 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since 2015, the International Bureau of Weights and Measures (BIPM) has started to organize the calibration of some NMIs. Thanks to the calibration campaign [7][8][9][10], the time delay is well measured. However, little is known about the long-term change in the time delay.…”

Section: Introductionmentioning

confidence: 88%

A Study of GPS Carrier-Phase Time Transfer Noise Based on NIST GPS Receivers

Yao

Levine

2016

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

To do a better time comparison between high-precision clocks (such as a Cesium-fountain clock and Hydrogen-maser clock), we want to study and eventually lower the GPS carrier-phase time transfer noise. The GPS carrier-phase time transfer noise comes from four sources: GPS satellite, GPS signal path, ground receiving equipment (receiver and antenna), and data-processing algorithm. This paper focuses on the noise introduced by the ground receiving equipment. At NIST, we have installed seven GPS receivers. All receivers have the same reference time, i.e., UTC(NIST). Three of them are connected to the same antenna. The other four are connected to four different antennas. This architecture enables us to study the time-transfer noise from the ground receiving equipment. We study both long-term (> 100 days) noise and short-term (< 1 day) noise. For the long-term noise, the time-transfer result using one receiver can vary from that using another receiver by up to 1.8 ns, during 1.3 years. To achieve sub-nanosecond GPS timing accuracy, a careful monitoring of the time delays or a more frequent calibration is needed. For the short-term noise, we find that the common-clock difference between receivers using the same antenna is less noisy than that using two different antennas, at an averaging time of less than 0.5 hour. This indicates that the antenna and antenna cable contribute to the super-short-term noise of GPS carrier-phase time transfer significantly. In addition, the response to the GPS receiver's reference-time change is tested in this paper. The variation in the response can be up to ± 350 ps. Last, this paper gives the best carrier-phase time transfer result we can currently achieve with the available equipment at NIST. The best frequency stability is 4.0×10 −16 at 3 hours, 1.1×10 −16 at 1 day, 4.0×10 −17 at 10 days, and 1.3×10 −17 at 48 days.

show abstract

Section: Introductionmentioning

confidence: 88%

A Study of GPS Carrier-Phase Time Transfer Noise Based on NIST GPS Receivers

Yao

Levine

2016

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

show abstract

“…This GAUT information can be compared to [GST − UTC] determined locally using equation (7). This equation includes the calibrated BIPM link on one hand, and the absolute calibration of the CS22 receiver chain on the other.…”

Section: Galileo To Utc Offsetmentioning

confidence: 99%

“…A relative calibration [7] can be used to transfer the calibration from a GNSS receiver chain with an absolute calibration to another GNSS receiver chain.…”

Section: Introductionmentioning

confidence: 99%

Absolute calibration of timing receiver chains at the nanosecond uncertainty level for GNSS time scales monitoring

Valat¹,

Delporte²

2020

Metrologia

View full text Add to dashboard Cite

The use of global navigation satellite systems (GNSS) for time transfer is widespread, in particular for the computation of the coordinated universal time (UTC). It is an inexpensive, easy-to-implement method to compare distant clocks. This time transfer method can also be applied to the monitoring of the GNSS time scales and of the broadcast UTC conversion parameters. One mission of the French space agency (CNES) is to perform this task for Galileo. For that purpose it is mandatory to carry out an absolute calibration of the propagation delay of a GNSS receiver chain. This propagation delay is the one between the GNSS antenna phase centre and the time reference that feeds the receiver chain. In order to allow a link to UTC, the time reference must be a UTC(k). CNES has developed a method of absolute calibration of GNSS receiver chains, in which the delays of the GNSS antenna, the antenna cable and the GNSS receiver are determined separately, with a total uncertainty in the range of 1 ns (1 – σ). The purpose of this paper is to present the method developed by CNES along with its uncertainty budget for GPS, Galileo and BeiDou signals. A validation in common-clock with actual GPS and Galileo signals is also provided. The absolute calibration is finally applied to an accurate monitoring of the GNSS time scales, the Galileo broadcast UTC conversion parameters and the broadcast Galileo to GPS time offset (GGTO), with associated uncertainties.

show abstract

“…The calibration of the GPS chain of the receiver was carried out by Observatoire de Paris (OP-SYRTE) during a calibration campaign carried out in 2014 in the frame of the TVF activities [4], and involving also the receiver of the first PTF at Fucino, Italy (PTF1), and the receivers at the five UTC(k) laboratories participating in the TVF [5].…”

Section: The Receiversmentioning

confidence: 99%

Relative Calibration of Galileo receivers within the Time Validation Facility (TVF)

Piriz

Rodríguez

Roldan

et al. 2015

2015 Joint Conference of the IEEE International Frequency Control Symposium &Amp; The European Frequency and Time Forum

Self Cite

View full text Add to dashboard Cite

GMV is the prime contractor for the Time and Geodetic Validation Facility (TGVF) in the Galileo FOC phase (Full Operational Capability), a contract of the European Space Agency (ESA). Within the TGVF, the Time Validation Facility (TVF) is the subsystem in charge of steering Galileo System Time (GST) to UTC, among other duties. The TVF is operated at GMV headquarters near Madrid, Spain. Calibrated Galileo receivers are needed in the frame of TVF activities to, among other tasks, assess the UTC-GST offset broadcast in the Galileo navigation message.Absolute receiver calibration is a complex activity involving the availability of a signal simulator and of a calibrated reference antenna. An alternative data-based method to evaluate the Galileo receiver delay in E5 signals relative to GPS is also possible. The key feature of such method is the cancellation of the GPS and Galileo ionospheric delays when combining pseudoranges from two satellites with a close position in the sky.A software tool called gecal has been developed by GMV within the Galileo TVF, implementing such method and processing RINEX 3 observation files. Satellite positions are read from a SP3 orbit file. The tool allows the rapid E5 calibration of a new or existing Galileo receiver. This paper describes the tool and the calibration of three Galileo receivers used in the TVF. Galileo Signal-In-Space validation results obtained using such receivers are also presented.

show abstract

Use of two traveling GPS receivers for a relative calibration campaign among European laboratories

Cited by 4 publications

References 9 publications

A Study of GPS Carrier-Phase Time Transfer Noise Based on NIST GPS Receivers

A Study of GPS Carrier-Phase Time Transfer Noise Based on NIST GPS Receivers

Absolute calibration of timing receiver chains at the nanosecond uncertainty level for GNSS time scales monitoring

Relative Calibration of Galileo receivers within the Time Validation Facility (TVF)

Contact Info

Product

Resources

About