19.1ET.01 - TIME TRANSFER USING LOW COST HIGH-GAIN ANTENNAS - EXPRO PLUS
Publication Date: 04-FEB-19
Program ref.: Technology Developme
Tender Type: C
Tender Status: INTENDED
Price Range: 200-500 KEURO
Budget Ref.: E/0901-01 - Technology Developme
Proc. Prop.: NO
Special Prov.: BE+DK+FR+DE+IT+NL+ES+SE+CH+GB+IE+AT+NO+FI+PT+GR+LU+CZ+RO+PL+EE+HU
Responsible: Crisci, Massimo
Products: Ground Segment / Ground Station / F&T equipment / Time Generation and Synchronisation equipment
Techology Domains: RF Systems, Payloads and Technologies / RF Technologies and Equipment / Time and Frequency RF Systems, Payloads and Technologies / Radio Navigation Systems/Subsystems / Ground Receivers
Industrial Policy Measure: C1 - Activities in open competition limited to the non-Larg...
Universal Coordinated Time (UTC) generation relies nowadays mostly on two techniques for time and frequency transfer: Two-Way Satellite Time and Frequency Transfer (TWSTFT) and Global Navigation Satellite Systems (GNSS). Both techniques present the following maincharacteristics: a) TWSTFT: accuracy 1-2ns, precision 100ps and usage of small high gain antennas to a geostationary channel in Ku-band with discrete measurements in observation windows. b) GNSS : accuracy 3-5ns, precision 20ps and usage of omnidirectional antennas and free L-Band signals with continuous measurements. TWSTFT remains as the principal technique for time transfer due to the better accuracy (1-2 ns) than GNSS, despite the many advantages in other areas (precision, continuity and cost). In term of cost, TWSTFTrequires leasing a dedicated link in a geostationary transponder and dedicated specialized hardware, while GNSS relies on free signals and standard geodetic equipment. Despite being the primary link technique in BIPM for the realization of UTC, only few time Laboratories use TWSTFT while all run GNSS equipment. A previous ESA activity, finalised in 2018, EGEP-ID103 "Accurate Calibration of Multisystem/Multi-Frequency GNSS Receiver Chains" has led to the development of a procedure and set-up for the full absolute calibration of GNSS chains with omnidirectional antennas. This procedure is expected to foster the use of Galileo in the timing community. However, EGEP-ID103 concluded that further improvements were limited by the calibration and the gain of the omnidirectional antenna (e.g. effects of multipath). This limitation is in principle removed by using a directional high gain antenna. The objective of this activity is to develop a new methodology combining the benefits of both time transfer techniques (TWSTFT and GNSS) by using low cost high gain antennas together with GNSS signals, with the following final performance targets: accuracy less than 1ns, precision 1ps and usage of free L-Band signals with continuous measurements. The expected benefits are in performance, cost and independence. This is deemedfeasible relying on free GNSS signals and the better capabilities of high gain antennas in terms of calibration capabilities and gain. Successful experience exists using low cost high gain antennas of up to 3 meter diameter at ESA and within European Industry forsupporting Galileo satellites calibration. The existing methodology has to be updated to cover high gain directional antennas calibration, benefits and issues. Then, the effort is devoted to the functional verification and final validation by the deployment of the calibrated high gain antenna chain at ESA/ESTEC and ESA/ESOC to link both time scale realizations towards a combined internationalrealization of UTC(ESA) time scale. Deliverables include the procedure, algorithmic model, software, hardware, a validation campaign between at least two UTC(k) realizations and the final deployment at ESA/ESTEC and ESA/ESOC including an acceptance campaign. Procurement Policy: C(1) = Activity restricted to non-prime contractors (incl. SMEs). For additional information please go to EMITS news "Industrial Policy measures for non-primes, SMEs and RD entities in ESA programmes".