Aircraft Sensor Specifications                                    

• 10.7 GHz -- HPol
• Synthetic Aperture 1 meter²
• Cross-track imaging
• Spatial res @ 11 km altitude
  • 381 x 466 m (nadir)
  • 436 x 484 m (17° cross track)
  • 1079 x 629 m (45° cross track)
• NEDT of 0.3K

Strategic Advantages

• No moving parts -- low risk
• Allows for multiple frequencies, polarization separation, and nadir or conical imaging
• Allows for co-boresighted and identical beamwidth radar and radiometer antenna patterns
• Inexpensive design

CLICK ON A LINK BELOW TO SEE PHOTOS OF LRR BEING BUILT

January 2003

February and March 2003

April and May 2003

Additional Photos

LRR System Calibration

• On board calibration provides ~2K absolute TB and ~0.2K stability

  • Inject correlated noise between each antenna and receiver for grains

  • Switch each channel to uncorrelated reference loads for offset

• Anechoic Chamber measurement of interference patterns

  • Determines relative spatial frequency response to each antenna pair

• Clear sky ocean radiobrightness model for end-to-end absolute calibration

  • Determines system gain (noise diode TBinjected) and offset (antenna ohmic losses) calibration parameter

  • Demonstrated operationally with TOPEX and Jason-1 Microwave Radiometers

    • ~1.0K accuracy and ~0.3K long term stability

Interferometric Aperture Synthesis

• Cross-correlation of signals from pairs of antennas with different baselines samples visibility function 

• Visibility function is Fourier transform of brightness temperature distribution of scene          

• Used in radio astronomy since 1950s

• First used in Earth Remote Sensing by ESTAR to measure sea surface salinity & soil moisture

• ESA SMOS Mission (launch ~2007) will be first spaceborne mission that will use technique

• Successful first aircraft flight demo of LRR-X in June 2003

LRR First Field Campaign -- Summary                               

• Integration onto DC-8, 12-17 May 2003                                

  • other sensors: JPL PR-2 (precip radar), JPL WindRad & PolScat (ocean surface wind vector), LaRC et al. DICE (in situ aerosols, aerosol lidar)

• Shakedown Flights, 28-29 May 2003

  • air dam added in front of LRR to reduce turbulence

• Engineering Check Flights, 29 May & 3 June 2003

  • ground beacon overflights confirm image impulses response

• WindSat Cal/Val Flights, 5 & 11 June 2003

  • Navy Coriolis cal/val overpasses                                    

• Precipitation and Mapping science Flights, 12 & 13 June 2003

  • Coastal Imaging, WA Cascade Range snowfall, Pac NW precip

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