1. PAU INSTRUMENT ABOARD INTA MICROSAT-1:A GNSS-R DEMONSTRATION MISSION FOR SEA STATE CORRECTION IN L-BAND RADIOMETRYA. Camps1, J.F. Marchn1,5, E. Valencia1, I. Ramos1, X. Bosch-Lluis1, N. Rodriguez1, H. Park1,A. Alcayde2, S. Chavero2, P. Martnez2, A. Mollfulleda2, J. Galindo2, M. Angulo3, and A. Rius41Dept.of Signal Theory and Communications, Universitat Politcnica de Catalunya and IEEC CRAE/UPC, UPC Campus Nord, D4-016, 08034 Barcelona, Spain. E-mail: camps@tsc.upc.edu 2ADTelecom, Cam de la Pelleria, 12, P.I. Bonavista, 08915 Badalona, Spain3INTA, Dept. Progrs. Espaciales y Ciencias del Espacio, Torrejn de Ardoz 28850, Madrid, Espaa4IEEC/ICE-CSIC, Campus UAB/Fac. Cincies, Torre C-5-parell-2a planta, 08193 Bellaterra, Spain 5Institut Cartogrfic de Catalunya, Parc de Montjuc, 08038 Barcelona, Spain IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 1

2. Outline of the presentation:1. Introduction2. Measurement Concept3. Instrument Heritage4. PAU in INTAs MicroSat-15. Preliminary Tests6. ConclusionsIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 2 3. 1. Introduction L-band microwave radiometry is the best suited forSea Surface Salinity and Soil Moisture e.g.: SMOS, Aquarius, SMAP missions The brightness temperature of the sea surface depends on: Th ,v ,SST,SSS 1 h ,v , r f ,SST, SSS SST Th ,v , param - salinity- physical temperature- sea state (surface roughness)critical correction: . SMOS: aux. data + multi-angular information . AQUARIUS: L-band scatterometer Potential solution = combination in a single instrument 3 different sensors:- PAU-RAD: New type of radiometer measure TB- PAU-GNSS/R:GPS reflectometer measure sea state (and altimetry)- PAU-IR:IR radiometer measure SST(PAU concept proposed to ESF in 2003, granted in 2004, cont MICIIN projects)IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 3 4. 2. Measurement Concept GNSS opportunity signals reflected over the seasurface come from a larger area (glistening zone)when the sea is rough longer delays as comparedto specular reflection point + larger Doppler shifts The Delay Doppler Map (DDM) provides an indication of the wideningof the so-called glistening zone related to TB may be used to correct for sea state Sample DDMs from UK-DMC (Tcoh.= 1 ms; Tincoh. = 200 ms)over the ocean, landand ice IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 4 5. 3. PAU Instrument Heritage (i)DO-DEREC early tests (July 2002)griPAU ground-based instrument40 km South of Barcelona(Gran Canaria, 2008 & 2009) sea state determination and impact on TB 24x32 DDM points (min =0.09 chips, fd=200 Hz) Tcoh. min = 1 ms / Tcoh. max = adjustable Tincoh. min = 1 ms / Tincoh. max = adjustable PAU-ORA(One Receiver Airborne): ALTIMETRIC & SM applicationsIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 5 6. 3. PAU Instrument Heritage (ii) TB Sensitivity to Normalized DDM VolumeMeasured DDM and threshold applied5x 105 x 10 32.5 22[au]1.5 11 200010002.5 0.5 021.5 -10001 -2000 0.5Doppler [Hz]Delay [chips]TB Sensitivity to Waveforms Tail LengthIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 20116 7. 4. PAU in INTAs MicroSat-1 (i):Sponsored by Spanish Ministry of Science and InnovationSistemas GNSS-R para Futuras Misiones SMOS: SUBPROYECTO UPC, code: AYA2008-05906-C02-01/ESP IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 7 8. 4. PAU in INTAs MicroSat-1 (ii):Simplified design: Radiometer operated as a TPR with frequent calibration, GNSS-Reflectometer operated while receiver is connected to the antenna, Combination of up-looking and down-looking channels through couplerFrequency plan: fRF = 1575.42 MHz, fIF = 70 MHz, fs = 16.384 MHzArchitecture: Two cold redundant receivers and processing boards.UP-looking antenna Processing board #1 Processing board #2DOWN-looking antennaIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 8 9. 4. PAU in INTAs MicroSat-1 (iii): Antenna Array Design1. Antenna array optimized for lowest possible ohmic losses and maximum gainPlanar structure (microstrip patches + stripline 8:1 power combiner < 6 mm thick)Patch GPS R4360f= 1575.42 MHzr = 6.15l = 36.6 mmh = 2.54 mmS11 = -25 dBG = 5.37 dB = 86%ArrayG = 15 dBIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 9 10. 4. PAU in INTAs MicroSat-1 (iv):All boards (Engineering Model final version pending) DPU VOLTAGE MAIN SUPPLYRFBOARD BOARDBOARD IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 10 11. 4. PAU in INTAs MicroSat-1 (v): RF/IF chain2. RF / IF chain to provide G ~ 110 dB gain, NF ~ 2 dB, B ~ 2.2 MHzG [dB]Gcum [dB]IP3 [dB]IP3cum [dB]NF [dB]NFcum [dB]IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 11 12. 4. PAU in INTAs MicroSat-1 (vi): DPU3. Signal Processor Virtex-4 FPGAs + in-orbit reconfiguration capability Interfaces: CAN (commands & reconfigurability), Space-Wire (data) DDM size: 4096* samples in delay x 16 samples in Doppler Dummy processing: Sequential search of all GPS satellites using1 ms coherent integration time + > 10 incoherent avg. (100 typ.) On-board NRT processing or raw data acquisitionIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 12 13. 4. PAU in INTAs MicroSat-1 (vii): DPUData Processing Unit Main Board (x 2: space-qualified + commercial compts.)CANinterfaceSRAMADC IF Input signal Back- PROMpanelSpaceWireconnector InterfaceFPGACLOCKGENERATIONIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 201113 14. 4. PAU in INTAs MicroSat-1 (viii): Boards being stacked IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 14 15. 4. PAU in INTAs MicroSat-1 (ix): Boards being stackedIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 15 16. 5. Preliminary Tests: (i)R&S SMU-200A arbitrary signal generator + GPS moduleAcquisition Set-upIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 16 17. 5. Preliminary Tests: (ii)Sampling = 6-bitLevel = GPS L1 C/A at ground levelTcoh =1 msNincoh =1fDoppler [Hz]Doppler [lags] Delay [lags]Delay [lags]IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 201117 18. 5. Preliminary Tests: (iii)Sampling = 6-bitLevel = GPS L1 C/A at ground level -15 dBTcoh = 2 msNincoh =50 Doppler [lags] Delay [lags] IGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 18 19. 6. Conclusions PAU in INTA MicroSat-1 is a small secondary payload to test sea state correction in L-band radiometric observations (TB vs Volume under the normalized DDM). Combination of direct and reflected signals will allow also to explore other scatterometric and altimetric measurements Planar antenna size limited by available space: trade-off between low ohmic losses (~86%), high gain (~15 dB), side lobes (-11 dB at 90), mass and thickness (< 6 mm). Computes real-time DDMs or stores raw data for ground processing Engineering Model finished and first tests performed. Current basic processing scheme: Tcoh = 1 ms, Nincoh. avg = 100 + blind sequential search of GPS satellites in viewIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 19 20. Acknowledgements:Activities sponsored by ESF EURYI 2004 grant and the Spanish Ministryof Science and Innovation Sistemas GNSS-R para Futuras MisionesSMOS: SUBPROYECTO UPC, code: AYA2008-05906-C02-01/ESPIGARSS 2011, Vancouver, Canada, July 25-29, 2011 UPC, ADTelecom 2011 20