On-ground tests and measurements of the Passive Advanced Unit Synthetic Aperture (PAU-SA) Isaac Ramos Pérez, Thesis Advisor: Adriano José Camps Carmona Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 21 st October 2010

Outline Introduction and objectives PAU-SAs concept Work Plan Potential improvements for future SMOSs PAU-SAs processor PAU-SAs assembled process Preliminary results Conclusions Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 2v

Introduction and objectives The SMOS mission: o Retrieve global and frequent data of Soil Moisture and Ocean Salinity o New kind of spaceborne Y-shaped aperture synthesis radiometer: MIRAS (Microwave Imaging Radiometer by Aperture Synthesis) o ESA Earth Explorer, Scheduled for 2010 Objective: o Test potential improvements for future MIRAS payloads New instrument: o Passive Advanced Unit - Synthetic Aperture (PAU-SA) o Award EURYI 2004 by A. Camps / Patented Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 3v

PAU-SA concept PAU-RAD PAU-GNSS-R PAU-IR Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 4v

Work Plan Study Potential Improvements (Software) Simulator (Mechanic) Mobile Unit (Truck) (Electronic) Device & testAssembleFull systems test Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 5v

Potential improvements for future SMOSs ParameterMIRAS/SMOSPAU-SA Comments Frequency operationL-band ( MHz) L-band ( MHz) L1 of GPS signal Same frequency both Radiometry and GPS Reflectrometry Bandwidth19 MHz2.2 MHz Spatial correlation effects are negligible Arm size4 m1.3 m AltitudeGlobal observation, LEO, orbital altitudeground-based Antenna type Patch antenna with V & H polarizations (not simultaneous) Patch antenna with V & H polarization (simultaneous) Full-pol (non-sequential) Number of antennas per arm238+1 (dummy) Improve G matrix condition number Number total antennas6931 Antenna spacing at 1400 MHz, (21 cm) at MHz, (15.5 cm) Increase the alias-free field of view Receiver type single polarization (1 per element) dual polarization (2 per element) Full-pol (non-sequential) Topology of the LO down- converter Distributed LO (groups of 6 elements) Centralized reference clock + internal LO generated in each receiver Reduce LO leakage and correlated offset Quantization 1 bit IF sampling depending upon the noise uptake level (Inside the LICEF ) 8 bits IF sub-sampling using a external ADC Used both digital I/Q demodulation (8 bits) digital Power measurement (8 bits) I/Q conversionAnalogDigital Mass reduction. Elimination phase error Frequency response shaped by Analog RF filterDigital low- pass filter Mass reduction, quasi perfect matching, no temperature and aging drifts Power measurement system (PMS) Analog, using classical methods (diode)Digital (FPGA) Mass reduction, No temperature drifts Calibration by Noise Injection Injection of Distributed noiseInjection of Centralized noise PRN Simple calibration. Calibration of non-separable errors Image capabilitiesDual-pol or full-pol (sequential) Full-pol (non-sequential) Necessary to GNSS-R applications Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 6v

PAU-SA processor Simulation Characterization Processing window Source panel Antenna panel Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 7v

PAU-SAs assembled process Structure AutoCAD design and implementation 1.3 m Mobile Unit AutoCAD design and implementation Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 8v

PAU-SAs assembled process PAU-SA in Assemble process Calibration and validation test PAU-SA instrument during integration process ADCs + FPGA (correlations and power estimation) Master clock and buffers for clock distribution Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 9v

PAU-SAs assembled process 1 st Barcelona Forum on Ph.D. Research in Electronic Engineering

Preliminary results Measurements at UPC anechoic chamber Power variance versus number of samples Normalized correlation (I and Q) vs. number of samples Minimum Allans variance for power at 15 s visibilities desnormalization Minimum Allans variance for normalized correlations (real and imaginary parts) for 200 s Real data: Single baseline response Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 11v

Preliminary results FFT Point Source : PRN or tone Moving the Instrument (without control temperature) El +/- 10º, +/- 20º Az +/- 10º, +/- 20º Pol H Az= 0º El= 0º Pol H Az= +10º El= 0ºPol H Az= +20º El= 0º Pol V Az= 0º El= +10ºPol V Az= 0º El= +20º PRN Signal Rectangular filter Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 12v

Conclusions Long Project with different tasks: –RF/FI Hardware designer - Digital Hardware: FPGA /PICs –Analog Hardware - Software programmer (Simulator) –System Assembled and tested – Director 5 PFCs (Coordination) –TEAM work, collaboration with: –GUTMAR (Mobile Unit) Project –Funcadió Eduard Soler (Mobile Unit) Mechanic –Student designers –PAU TEAM (brainstorm meetings ) –Several UPC personal Implementation of an end-to-end physically-based simulator for data acquisition & processing, PAU-SAs instrument has been assembled and tested internally, Preliminary test with the instrument has been done successfully, Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 13v

Thank you for your attention Barcelona Forum on Ph.D. Research in Communications, Electronics and Signal Processing 14v