From Pascale.Defraigne@ksb-orb.oma.be Fri Feb 20 05:30 EST 1998 Received: from helios.oma.be (helios-fddi.oma.be) by Maia.usno.navy.mil with ESMTP (1.37.109.24/16.2) id AA116330620; Fri, 20 Feb 1998 05:30:20 -0500 Return-Path:Received: (from Pascale.Defraigne@helios.oma.be) by helios.oma.be (8.7.5/8.7.1) id KAA11168; Fri, 20 Feb 1998 10:31:32 GMT From: Pascale Defraigne Message-Id: <199802201031.KAA11168@helios.oma.be> Subject: Response to CALL To: jimr@Maia.usno.navy.mil Date: Fri, 20 Feb 1998 10:31:32 +0000 (UTC) Cc: cthomas@bipm.fr X-Mailer: ELM [$Revision: 1.16.213.5 $] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Status: RO Response to CALL FOR PARTICIPATION in an IGS/BIPM PILOT PROJECT TO STUDY ACCURATE TIME AND FREQUENCY COMPARISONS USING GPS PHASE AND CODE MEASUREMENTS Agency or group: Royal Observatory of Belgium (ROB) Av. Circulaire 3 B-1180 Brussels Belgium Contact person(s): Carine BRUYNINX Pascale DEFRAIGNE Rene WARNANT E-mail address(es): C.Bruyninx@oma.be P.Defraigne@oma.be R.Warnant@oma.be Areas of participation: 1) Deployment of GPS receivers: Yes 2) GPS data analysis: No 3) Analysis of instrumental delays: Yes 4) Time transfer comparisons: No 5) Other: clock comparisons by single differences on phases is foreseen Limitations on participation: (please list any restrictions) Comments or suggestions: The Royal Observatory of Belgium combines two observational activities relevant to the IGS/BIPM pilot project : - The permanent TurboRogue GPS receiver in Brussels belongs, since November 1993, to the IGS network (as a non-global station) and is therefore included into the ITRF. Precise reference frequency is provided to the GPS receiver by a hydrogen Maser maintained by the ROB time laboratory. - The time laboratory of the ROB participates to the realization of TAI by sending the measurements of its clocks to the BIPM. In 1997, data from 3 Cesium clocks and one Maser clock were submitted to the BIPM. The ROB clocks are located in thermostatised basements with limited humidity and temperature variations. The time transfer to TAI is presently done using a NBS type receiver. From mid-1998 a double frequency GLONASS/GPS (3S-Navigation : R-100/40T) will be used for both time transfer and participation to the upcoming IGEX-98 GLONASS observation campaign. A 8-channel Motorola Oncore receiver is also planned to be put into operation during 1998. The L1-L2 differential instrumental delays of the GPS receiver in Brussels have been determined and are continuously monitored since 1993. This work is done within the frame of a study of the ionospheric disturbance on the GPS signal. This long experience demonstrates the relevant contribution of the ROB with respect to the analysis of instrumental delays as proposed in the IGS/BIPM pilot project. Taking the above mentioned activities into account, the ROB proposes to contribute to the IGS/BIPM Pilot Project with : - the data from its permanent GPS (TurboRogue) and GLONASS (3S-Navigation,R-100/40T) receivers in Brussels - a contribution to the analysis of receiver specific instrumental delays