PARIS Ocean Altimeter

Transcription

1 PARIS Ocean Altimeter M. Martín-Neira, S. D Addio (TEC-ETP) European Space Agency Acknowledgment: C. Buck (TEC-ETP) N. Floury, R. Prieto (TEC-EEP) GNSS-R10 Workshop, UPC, Barcelona, October /20

2 Objective The PARIS Ocean Altimeter is the payload of the PARIS In-Orbit Demonstrator PARIS IoD objective To explore the use of GNSS reflected signals for scientific applications: - Number of GNSS satellites will be above 150 and for decades (important in climatology) - Focus of PARIS IoD is mesoscale ocean altimetry (most stringent application foreseen) - The demonstration of mesoscale ocean altimetry could lead into a follow-on on mission GNSS-R10 Workshop, UPC, Barcelona, October /20

3 Mission Summary GNSS-R10 Workshop, UPC, Barcelona, October /20

4 PARIS IoD Concept High gain beams for direct signals (D) High gain beams for reflected signals (R) Observables obtained by cross-correlation (DxR) Implicit use of full GNSS bandwidth (3x40 MHz) Precise estimation of ionospheric delay Low noise ionospheric correction Precise on-board delay calibration Precise on-board amplitude calibration L5 L2 L1 40 MHz 40 MHz 40 MHz GNSS-R10 Workshop, UPC, Barcelona, October /20

5 Interferometric Processing Amplitude [A.U.] 6 x Normalized Cross-Correlation Power Waveform C/A code GPS L C/A 1 L1 interferometric 10-fold improvement demonstrated from a bridge in quasi-specular conditions Next step: aircraft experiment in diffused conditions ( a 3-fold precision improvement expected, at least ) Delay [Chips] GNSS-R10 Workshop, UPC, Barcelona, October /20

6 Specular Pointing PARIS IoD 4 specular points (GPS + GALILEO) Operational mission 20 specular points GPS + GALILEO + GLONASS + BEIDOU + INSS GNSS-R10 Workshop, UPC, Barcelona, October /20

7 Non-specular Pointing - Exploring new applications: : SWH, ocean surface currents, swell (and rogue) waves G G P P Backscatter 0 doppler line B S D S (a) Backscatter (b) 0-doppler 0 line GNSS-R10 Workshop, UPC, Barcelona, October /20

8 Ionospheric Correction I - One of the main goals of this demonstrator is to show that the large ionospheric delay at L-band can be corrected accurately from orbit to keep the required altimetric performance G 1 G 2 P Ionosphere i i s 1 s 2 O GNSS-R10 Workshop, UPC, Barcelona, October /20

9 Ionospheric Correction II Vertical Delay (m) m Derived from RA-2 real data m Mesoscale Delay (m) m m Residual Delay (m) m km averaging of mesoscale delay applied m GNSS-R10 Workshop, UPC, Barcelona, October /20

10 PARIS Ocean Altimeter Antenna - Double phased-array array with 19 elements on each side - Dual frequency: GPS L1 and L5 (Galileo E1 and E5) 0.9 m space for the electronics height < 11 cm Uplooking antenna Downlooking antenna GNSS-R10 Workshop, UPC, Barcelona, October /20

11 Antenna Element Pairing Up Concept Up-looking Antenna Elements Pressure connector 10 mm Honeycomb panel Electrical Harness Calibration Switch and LNA Aluminium Beam Pressure connector 10 mm Honeycomb panel < 11 cm Down-looking Antenna Elements GNSS-R10 Workshop, UPC, Barcelona, October /20

12 PARIS Ocean Altimeter Beamformers Beamformer B S1 Switch circuit UP 1 Antenna element Beamformer A T1 B1 1 B2 Sn LNA BPF B3 Power Divider Tn Phase Shifter DOWN DOWN 1 UP m Power Combiner UP 1 DOWN m GNSS-R10 Workshop, UPC, Barcelona, October /20

13 PARIS Ocean Altimeter Block Diagram GNSS receiver Ground Station (S-band uplink) GNSS-R10 Workshop, UPC, Barcelona, October /20

14 Delay and Amplitude Calibration - Accurate delay and amplitude calibration are essential for the scientific exploitation of the GNSS signals - Delay calibration is proposed by the swapping technique, for example - Amplitude calibration is based on radiometer techniques, using the cold sky and a matched load - The calibration box in-between the paired up-down elements performs the required switching of the inputs UP 1:2 switch 1:3 switch LNA 2 loads LNA 1 1:3 switch 1:2 switch DOWN GNSS-R10 Workshop, UPC, Barcelona, October /20

15 Preliminary Mass Budget TET Capability 47 kg GNSS-R10 Workshop, UPC, Barcelona, October /20

16 Preliminary Power Budget Payload Average Power Consumption < 100 W GNSS-R10 Workshop, UPC, Barcelona, October /20

17 Preliminary Mass and Power Budgets Summary PARIS IoD preliminary mass and power budgets are compatible with the TET platform GNSS-R10 Workshop, UPC, Barcelona, October /20

18 Payload Accommodation Stowed Configuration Antenna hold-down and release mechanism GNSS-R10 Workshop, UPC, Barcelona, October /20

19 Payload Accommodation on TET Platform Payload Electronics TET Platform PARIS Double-phased Array Deployment mechanisms and signal harness GNSS-R10 Workshop, UPC, Barcelona, October /20

20 PARIS IoD Launch Scenario Main passenger PARIS IoD GNSS-R10 Workshop, UPC, Barcelona, October /20

21 PARIS IoD Overall Planning Budget Consolidation Proof of Concept Critical Breadboarding Phase A APPROVED RUNNING ACTIVITIES GNSS-R10 Aircraft Test ACTIVITIES PENDING OF FUNDING Pot money TRP GSTP GSP GALILEO Evolution TBD Phase B Simulator and Ground Campaigns Phase C/D Launch Campaign late 2016 Launch in early 2017 GNSS-R10 Workshop, UPC, Barcelona, October /20