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Last name: SAMAIN
First name: Etienne
International audience
COupled SLope and scIntillation Detection And Ranging (CO-SLIDAR) is a recent profiling method of the vertical distribution of atmospheric turbulence strength ( Cn2 profile). It takes advantage of correlations of slopes and of scintillation, both measured with a Shack-Hartmann wavefront sensor on a binary star. In this paper, we present the...
The Time Transfer by Laser Link (T2L2) experiment, developed by both CNES and OCA, performs ground to ground time transfer over intercontinental distances. The principle is derived from laser telemetry technology with dedicated space equipment designed to record arrival time of laser pulses at the satellite. Using laser pulses instead of radio...
In order to address the high throughput requested for both downlink and uplink satellite to ground laser links, adaptive optics (AO) has become a key technology. While maturing, application of this technology for satellite to ground telecommunication, however, faces difficulties, such as higher bandwidth and optimal operation for a wide variety...
In October 2012, the Ge?oazur TF laboratory in OCA has been reorganized to improve signal distribution stability. In particular we have implemented a new time scale TA(OCA) based on H-maser T4Science. The H-maser frequency is steered with an HROG-10 microphase stepper. The correction applied is computed every day taking into account the...
In this work, we report recent progress on the design of all-fibered ultra-high repetition-rate pulse sources for telecommunication applications around 1550 nm. The sources are based on the non-linear compression of an initial beat-signal through a multiple four-wave mixing process taking place into an optical fiber. We experimentally...
In this paper, we report recent progress on the design of all-fibered ultra-high repetition-rate pulse sources for telecommunication applications around 1550 nm. Based on the nonlinear compression of an initial beat-signal in optical fibers through a multiple four-wave mixing process, we theoretically and experimentally demonstrate that this...
Three independent time transfer techniques are in use in Observatoire de la Côte d'Azur (OCA): GPS, TWSTFT and T2L2. In Autumn 2013, a GPS receiver relative calibration campaign has been carried out. The result of this campaign, primary intended to compare GPS with T2L2, have allowed the calibration of the TWSTFT link between OCA and OP. We...
International audience
International audience
The new generation of optical time transfer will allow the synchronization of remote ultra stable clocks and the determination of their performances over intercontinen-tal distances. The principle of T2L2 (Time Transfer by Laser Link) is based on the techniques of satellite laser ranging coupled with time-frequency metrology. It consists of...
The Time Transfer by Laser Link (T2L2) experiment aims at achieving ground to ground time transfer between remote clocks using time tagging of laser pulses. The principle is derived from laser telemetry technology with a dedicated space equipment designed to record arrival epoch of laser pulses at the satellite. The use of laser pulses, instead...
International audience
Since late 2014, OCA LLR station has been able to range with infrared wavelength (1064nm). IR ranging provides both temporal and spatial improvement in the LLR observations. IR detection also permits in densification of normal points, including the L1 and L2 retroreflectors due to better signal to noise ratio. This contributes to a better...
This paper presents a direct comparison of two time transfer techniques on independently calibrated links: Time Transfer by Laser Link (T2L2) and Global Positioning System (GPS) satellite common-views (CV). The two different techniques are described, along with the independent link calibrations. The results achieved during one measurement...
The Time Transfer by Laser Link (T2L2) project is designed for the comparison of ground clocks utilizing a space instrument able to time tag laser pulses reaching the satellite and a SLR station network. Compared to the microwave techniques, such as the GPS-Common View, T2L2 should improve the time transfer uncertainty by at least one order of...
Downlink measurement campaigns from the optical downlink terminal OSIRISv1 onboard the LEO satellite Flying Laptop were carried out with the French Observatoire de la Côte d'Azur and with two Optical Ground Stations of the German Aerospace Center. On/off keyed data at 39 Mb/s were modulated on the laser signal, and according telecom reception...
T2L2 (Time Transfer by Laser Link) permits the synchronization of remote ultra stable clocks over intercontinental distances. The principle is based upon laser telemetry technology with a network of laser stations on ground and dedicated space equipment designed to record arrival time of laser pulses at the satellite. T2L2 allows realization of...
International audience
Based on a fully passive space segment, the lunar laser ranging experiment is the last of the Apollo Lunar Surface Experiments Package to operate. Observations from the Grasse lunar laser ranging station have been made on a daily basis since the first echoes obtained in 1981. In this paper, first, we review the principle and the technical...
Based on a fully passive space segment, the Lunar Laser Ranging experiment is the last of the Apollo Lunar Surface Experiments Package to operate. Observations from Grasse Lunar Laser Ranging station have been realized on a daily basis since the first echoes obtained in 1981. We will give a brief summary of the progress made at Grasse Laser...
Based on a fully passive space segment, the lunar laser ranging experiment is the last of the Apollo Lunar Surface Experiments Package to operate. Observations from the Grasse lunar laser ranging station have been made on a daily basis since the first echoes obtained in 1981. In this paper, first, we review the principle and the technical...
The Grasse Satellite Laser Ranging (SLR) station (ID7845), part of the International Laser Ranging Service (ILRS) network, participates to various laser applications including SLR, Lunar Laser Ranging (LLR), Time Transfer by Laser Link (T2L2), high-resolution imagery, and debris detection. Since 2014, in collaboration with the France Space...