| Publication type: |
 |
Conference proceedings |
|
| Subject: |
|
Sciences of the Universe/Ocean, Atmosphere
|
|
| Title: |
|
Field of view characteristics of a microwave 2D interferometric antenna as illustrated by the MIRAS concept. |
|
| Author(s): |
|
Philippe Waldteufel 1, Eric Anterrieu ( ) 2, Jean-Marc Goutoule, Yann Kerr 3 |
|
| Laboratory: |
|
|
|
| Abstract: |
|
Recently developed interferometric techniques allow to design realistic space missions using L-Band radiometry, devoted to remote sensing of soil moisture (over land) and surface salinity (over the ocean) at the Earth surface. The SMOS mission, submitted to the European Space Agency, uses the 2-D interferometric MIRAS concept, developed since 1993 by ESA. The MIRAS antenna is a Y shaped structure, each arm of which consists of aligned, adjacent elementary antennas. Visibility functions are retrieved from the correlation products constructed from the signals collected by elementary antennas, then transformed into brightness temperature maps. The field of view (FOV) is limited both by the solid angle where visibility functions can be reconstructed and by aliased Earth images. The alias free FOV roughly consists of two regions. In the "inner" swath, a large range of look angles is explored instantaneously ; the same region on Earth can thus be seen for a variety of incidence angles. This may strongly improve the accuracy and power of retrieving procedures. In the "outer" swath, the range of angles decreases: the 2-D radiometer then becomes comparable to a conical scanning radiometer. This duality may help to optimise mission scenarios in terms of revisit time and measurement performances. Over the ocean, an averaging procedure is necessary, in order to estimate surface salinity with adequate accuracy. What then matters is the total number and accuracy of instantaneous independant views. It is shown that 2-D interferometric designs do not suffer major degradations when compared to real antennas. |
|
| Fulltext language: |
|
English |
|
|
| Book title: |
|
Proc. 6th Specialist Meeting on Microwave Radiometry & Remote Sensing Applications (μRAD'99), Florence (Italia), 16-18 March 1999. |
|
| Publication date: |
|
1999 |
|
| Page, identifiant, ...: |
|
477-483 |
|
|
| Conference date: |
|
1999 |
|
|
Export this paper
