Aquarius Maps: Scatterometer RFI (Southern Hemisphere)

  • Scatterometer RFI, September 2011

    September 2011

  • Scatterometer RFI, October 2011

    October 2011

  • Scatterometer RFI, November 2011

    November 2011

  • Scatterometer RFI, December 2011

    December 2011

  • Scatterometer RFI, January 2012

    January 2012

  • Scatterometer RFI, February 2012

    February 2012

  • Scatterometer RFI, March 2012

    March 2012

  • Scatterometer RFI, April 2012

    April 2012

  • Scatterometer RFI, May 2012

    May 2012

  • Scatterometer RFI, June 2012

    June 2012

  • Scatterometer RFI, July 2012

    July 2012

  • Scatterometer RFI, August 2012

    August 2012

  • Scatterometer RFI, September 2012

    September 2012

  • Scatterometer RFI, October 2012

    October 2012

  • Scatterometer RFI, November 2012

    November 2012

  • Scatterometer RFI, December 2012

    December 2012

  • Scatterometer RFI, January 2013

    January 2013

  • Scatterometer RFI, February 2013

    February 2013

  • Scatterometer RFI, March 2013

    March 2013

  • Scatterometer RFI, April 2013

    April 2013

  • Scatterometer RFI, May 2013

    May 2013

  • Scatterometer RFI, June 2013

    June 2013

  • Scatterometer RFI, July 2013

    July 2013

  • Scatterometer RFI, August 2013

    August 2013

  • Scatterometer RFI, September 2013

    September 2013

  • Scatterometer RFI, October 2013

    October 2013

  • Scatterometer RFI, November 2013

    November 2013

  • Scatterometer RFI, December 2013

    December 2013

  • Scatterometer RFI, January 2014

    January 2014

  • Scatterometer RFI, February 2014

    February 2014

  • Scatterometer RFI, March 2014

    March 2014

  • Scatterometer RFI, April 2014

    April 2014

  • Scatterometer RFI, May 2014

    May 2014

  • Scatterometer RFI, June 2014

    June 2014

  • Scatterometer RFI, July 2014

    July 2014

  • Scatterometer RFI, August 2014

    August 2014

  • Scatterometer RFI, September 2014

    September 2014

  • Scatterometer RFI, October 2014

    October 2014

  • Scatterometer RFI, November 2014

    November 2014

  • Scatterometer RFI, December 2014

    December 2014

  • Scatterometer RFI, January 2015

    January 2015

  • Scatterometer RFI, February 2015

    February 2015

  • Scatterometer RFI, March 2015

    March 2015

  • Scatterometer RFI, April 2015

    April 2015

  • Scatterometer RFI, May 2015

    May 2015

  • Credit
  • Credit
Slideshow: Monthly scatterometer RFI at 1.26 GHz (hover over images to pause the slideshow).

Radio Frequency Interference (RFI) can cause errors in the salinity estimated by Aquarius by affecting the signal received by the microwave radiometers and the scatterometer. The scatterometer is important for correcting for the effect of ocean waves (surface roughness). The images on this page show global monthly RFI for ascending/descending passes as detected by the scatterometer in the Orthographic Southern Hemisphere (Le Vine and de Matthaeis, 2014), at 1.26 GHz, the frequency of the Aquarius scatterometer.

Each data point represents the average of scatterometer measurements over 1.44 seconds (the fundamental data block in Aquarius Level 2 data). The color scale indicates the percentage of radiometer measurements within this window that are identified as RFI by the RFI detection algorithm (Le Vine and de Matthaeis, 2014). Measurements identified as RFI are removed from processing and not used to calculate salinity. Red colors indicate areas where over 80% of the sampled data are flagged for RFI presence. Dark blues show relatively little detected RFI, with less than about 10% of samples flagged in these regions.

The scatterometer operated in a band shared with other active "services" including air traffic control radars, which are known sources of interference. Fortunately, over the ocean where the scatterometer data are needed most, the interference is small; however, over land there is significant and persistent interference with the scatterometer signal.

Click here to view a slideshow of scatterometer RFI in the northern hemisphere.

Images are provided by Paolo de Matthaeis, NASA Goddard Space Flight Center.

References
Le Vine, D. and de Matthaeis, P. (2014). Aquarius Active/Passive RFI Environment at L-band, IEEE T. Geosci. Remote Let, 11 (10), 1747-1751.
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