A5058518372- Soil Moisture and Remote Sensing
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Precipitation Measurement and Analysis
- Cryospheric studies and observations
- Radio Astronomy Observations and Technology
- Antenna Design and Optimization
- Ocean Waves and Remote Sensing
- Arctic and Antarctic ice dynamics
- Geophysics and Gravity Measurements
- Calibration and Measurement Techniques
- Climate change and permafrost
- Oceanographic and Atmospheric Processes
- Microwave Engineering and Waveguides
- Antenna Design and Analysis
- Underwater Acoustics Research
- Magneto-Optical Properties and Applications
- Geomagnetism and Paleomagnetism Studies
- Spacecraft and Cryogenic Technologies
- Superconducting and THz Device Technology
- Microwave and Dielectric Measurement Techniques
- Geophysical and Geoelectrical Methods
- Scientific Research and Discoveries
- CCD and CMOS Imaging Sensors
- Magnetic Properties and Applications
- Astronomical Observations and Instrumentation
Universitat Politècnica de Catalunya
2013-2022
European Space Research and Technology Centre
2005-2010
European Space Agency
2010
Institut d'Estudis Espacials de Catalunya
2008
Center For Remote Sensing (United States)
2008
Empresarios Agrupados
2004
Universitat de Barcelona
2003
FC Barcelona
2002
The fundamental equation of interferometric aperture synthesis radiometry is revised to include full antenna pattern characterization and receivers' interaction. It shown that the cross correlation between output signals a pair receivers Fourier-like integral difference scene brightness temperature physical receivers. derivation performed using thermodynamic approach account for effects mutual coupling elements. analysis assumes ferrite isolators so noise wave passing from receiver toward...
Soil Moisture and Ocean Salinity (SMOS) is an Earth Explorer Opportunity Mission from the European Space Agency with a launch date in 2007. Its goal to produce global maps of soil moisture ocean salinity variables for climatic studies using new dual-polarization L-band (1400-1427 MHz) radiometer Microwave Imaging Radiometer by Aperture Synthesis (MIRAS). SMOS will have multiangular observation capability can be optionally operated full-polarimetric mode. At this frequency sensitivity...
After the successful launching of Soil Moisture and Ocean Salinity satellite in November 2009, continuous streams data started to be regularly downloaded made available processed. The first six months operation were fully dedicated In-Orbit Commissioning Phase, with an intense activity aimed at bringing instrument into a operational condition. Concerning payload Microwave Imaging Radiometer Aperture Synthesis, it was characterized using specific orbits check all modes. procedures, already...
End-to-end calibration of the Microwave Imaging Radiometer by Aperture Synthesis (MIRAS) radiometer refers to processing measured raw data up dual-polarization brightness temperature maps over earth's surface, which is level 1 product Soil Moisture and Ocean Salinity (SMOS) mission. The process starts with a self-correction comparators offset quadrature error followed procedure itself. This one based on periodically injecting correlated uncorrelated noise all receivers in order measure their...
Sea surface salinity can be measured by microwave radiometry at L-band (1400-1427 MHz). This frequency is a compromise between sensitivity to the salinity, small atmospheric perturbation, and reasonable pixel resolution. The description of ocean emission depends on two main factors: (1) sea water permittivity, which function temperature, frequency, (2) state, wind-induced wave spectrum, swell, rain-induced roughness foam coverage its emissivity. study presents simplified two-layer model for...
The European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission aims at producing global frequent maps of SMOS will be launched in 2008. SMOS' single payload is a new type radiometer called Microwave Imaging Radiometer by Aperture Synthesis (MIRAS) operating L-band which brightness temperature images are formed Fourier synthesis technique. However, the alias-free field view where reconstructed, bias present has been found to higher for high-contrast scenes (coastlines) lower...
Brightness-temperature retrieval techniques for synthetic aperture radiometers are reviewed. Three different approaches to combine measured visibility and antenna temperatures, along with instrument characterization data, into a general equation invert presented. Discretization windowing briefly discussed, formulas reciprocal grids using rectangular hexagonal samplings given. Two known used the equation, namely, inverse Fourier transform <i xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Land-sea contamination observed in Soil Moisture and Ocean Salinity (SMOS) brightness temperature images is found to have two main contributions: the floor error inherent of image reconstruction a multiplicative either antenna or visibility samples measured by correlator. The origin this last one traced down SMOS calibration parameters yield simple correction scheme, which validated against several geophysical scenarios. Autoconsistency rules interferometric synthesis together with redundant...
The Microwave Imaging Radiometer by Aperture Synthesis (MIRAS) is the single payload of European Space Agency's (ESA) Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity mission. MIRAS will be first two-dimensional aperture synthesis radiometer for observation. Two-dimensional radiometers can generate brightness temperature images a Fourier process without mechanical antenna steering. To do so have necessary wide swath observation, array formed small low directive antennas,...
A software package to fully process SMOS data from level 0 up brightness temperature at antenna plane (level 1B) is described. The raw downloaded the payload are converted correlations and voltages; then calibrated visibility temperature; finally temperature. Results different levels saved in separate files for further post-processing a visualization tool provided order check various levels, as well producing maps (xi, eta) domain. has been developed independently official SMOS-mission...
The SMOS Earth Explorer Opportunity Mission was selected in May 1999 by the European Space Agency to provide global and frequent soil moisture sea salinity maps. SMOS' single payload is MIRAS (Microwave Imaging Radiometer Aperture Synthesis), an L-band two-dimensional aperture synthesis interferometric radiometer with multi-angular observation capabilities. Two-dimensional brightness temperature images are obtained processing cross-relations measured pairs of signals collected each 72...
The Soil Moisture and Ocean Salinity (SMOS) mission was selected in May 1999 by the European Space Agency to provide global frequent soil moisture sea surface salinity maps. SMOS' single payload is Microwave Imaging Radiometer Aperture Synthesis (MIRAS), an L band two‐dimensional aperture synthesis interferometric radiometer with multiangular observation capabilities. Most geophysical parameter retrieval errors studies have assumed independence of measurements both time space so that...
The European Space Agency's Soil Moisture and Ocean Salinity (SMOS) mission will be the first one using two-dimensional aperture synthesis radiometry for Earth observation. This study presents formulation that relates instrument observables brightness temperature maps including cross-polar antenna voltage patterns, which may also different from element to element. Finally, radiometric accuracy degradation if patterns are neglected in image reconstruction is studied.
The on-ground characterization of the synthetic aperture radiometer onboard Soil Moisture and Ocean Salinity mission is described. Characterization includes basic functionality, internal calibration, thermal cycling, response to point flat sources, self-radio-frequency interference, others. description different tests performed as well detailed results are provided. show that instrument very stable has all gains offsets consistent with ones obtained at subsystem level. On other hand, phase...
Since each of the individual elements MIRAS array is a total power radiometer, zero-spacing visibility can be obtained by average all corresponding antenna temperatures. The main advantage this option with respect to using NIR measurements that amplitude calibration more consistent between and rest. On other hand, radiometers are not usually as stable noise injection radiometers, so small loose stability could expected. Preliminary results show, however, similar performance.
Soil moisture and ocean salinity at surface level can be measured by passive microwave remote sensing L‐band. To provide global coverage data of soil with three‐day revisit time, the Earth Explorer Opportunity Mission SMOS (Soil Moisture Ocean Salinity) was selected ESA (European Space Agency) in May 1999. SMOS' single payload is a Y‐shaped 2‐D aperture synthesis interferometric radiometer called MIRAS (Microwave Imaging Radiometer Aperture Synthesis). presents some particular imaging...
Sea surface salinity can be measured by passive microwave remote sensing at L-band. In May 1999, the European Space Agency (ESA) selected Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity Mission to provide global coverage of soil moisture ocean salinity. To determine effect wind on sea emissivity, ESA sponsored Wind Experiment (WISE 2000). This paper describes field campaign, measurements acquired with emphasis in radiometric L-band, their comparison numerical models,...
The Soil Moisture and Ocean Salinity (SMOS) Earth Explorer Opportunity Mission was selected in May 1999 by the European Space Agency Observation Programme Board to provide global frequent soil moisture (SM) sea surface salinity (SSS) maps. SMOS' single payload is Microwave Imaging Radiometer Aperture Synthesis (MIRAS) sensor, an L-band two-dimensional aperture synthesis interferometric radiometer with multiangular polarimetric imaging capabilities. definition of SMOS Level 2 Processor...
A complete and systematic noise analysis of radiometer front-ends, including both total power correlation measurements, is presented. The procedure uses the concepts waves S-parameters, widely used in microwave systems design takes into account full characterization receivers mismatch effects. general formulation compatible with known specially appropriate radiometers for which effect nonideal components, such as input isolators, analyzed. Along numerical simulations, simple formulas are...
This paper describes AMIRAS, an airborne demonstrator of the Microwave Imaging Radiometer with Aperture Synthesis, which is instrument onboard ESA's Soil Moisture and Ocean Salinity (SMOS) mission. The main electrical, mechanical, thermal, control elements are shown, together its capabilities performances as spaceborne instrument. AMIRAS tests inside anechoic chamber, field ground experiments, first two maiden flights reported, some results these highlighted. will further be used in...
SMOS brightness temperature images show some residual artifacts as a function of spatial directions. Due to having different antenna patterns in each element, even if knowing them perfectly, minimum reconstruction error inherent the inversion algorithm exists. On top that, measurement errors and other effects such cross-polarization terms, increase biases. Accurate characterization these sources allows improving quality images. Good results this direction are reported.
This paper reviews the relative calibration of an interferometric radiometer taking into account experimental results first batch receivers developed in frame European Space Agency's Soil Moisture and Ocean Salinity mission. Measurements show state-of-the-art baseline performance as long system is capable correcting effect orbital temperature swing. A method to validate internal during in-orbit deep-sky views correct linearity errors also presented.
This work has been conducted in the framework of several projects devoted to assess performance Soil Moisture and Ocean Salinity (SMOS) mission full-pol measurement mode. Since its launch November 2009, SMOS is producing dual-polarization brightness temperature synthesized images that are yielding a high scientific return. However, these affected by non-negligible spatial amplitude error, so-called bias (SB), degrades geophysical parameter retrieval. effect particularly detrimental...
Faraday rotation is dynamically computed from L-band radiometric data acquired by the Soil Moisture and Ocean Salinity satellite. Improved full polarimetric image reconstruction smart spatiotemporal filtering are used to obtain good estimations of rotation, which compare very well with values theoretically predicted available ionosphere geomagnetic field data.