A Novel Digital IQ Demodulation for Interferometric Radiometers

Ignasi Corbella,Albert Catalan,Manuel Martín Neira,Roger Vilaseca,Francesc Torres,Martin Suess

doi:10.3390/rs13061156

Ignasi Corbella, Albert Catalan + Show 4 more

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https://doi.org/10.3390/rs13061156

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Abstract

In the frame of an SMOS follow-on operational mission, a new instrument design is being developed based on the lessons learned from MIRAS, the SMOS payload. To reduce hardware complexity and mass, digital In-phase Quadrature (IQ) demodulation is considered. In this schema, Q components are obtained by delaying one clock of the digitized IF signals instead of using phase quadrature analog mixers. The purpose of this article is to formulate this concept for application to interferometric radiometry, establish the required data processing methods, and provide experimental results.

Highlights

IntroductionInterferometric radiometry is a technique to obtain brightness temperature images using large arrays of antennas in order to achieve a spatial resolution similar to that of real apertures of a similar size
Demodulation for InterferometricInterferometric radiometry is a technique to obtain brightness temperature images using large arrays of antennas in order to achieve a spatial resolution similar to that of real apertures of a similar size
In the frame of developing an SMOS follow-on operational mission, a new instrument design was proposed taking into account the lessons learned [3] from the SMOS single payload MIRAS [4]

Summary

Introduction

Interferometric radiometry is a technique to obtain brightness temperature images using large arrays of antennas in order to achieve a spatial resolution similar to that of real apertures of a similar size. It has been used for decades in radio astronomy and has been successfully applied for Earth observation in the ESA’s (European Space Agency) SMOS (Soil Moisture and Ocean Salinity) mission. In the frame of developing an SMOS follow-on operational mission, a new instrument design was proposed taking into account the lessons learned [3] from the SMOS single payload MIRAS [4] To increase radiometric performances, a hexagonal structure is considered [5], so the total number of receivers becomes larger (74% increase) than its counterpart MIRAS

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