Specifications of APL/UW's COherent Real Aperture Radar (CORAR)



CORAR operates in both a rotating and imaging mode simultaneously.  
The rotating mode may be implemented in 2 different configurations 
and the imaging mode in 3.  Furthermore a third mode in which the 
rotating antennas are disconnected allows pulse-to-pulse switching 
between HH and VV polarizations in the imagery.  These are all 
outlined below:


COMMON SPECIFICATIONS:

Microwave Frequency				9.360 GHz
Polarization					HH, VV
Peak Power Transmitted				100 W
Pulse Repetition Frequency			40 kHz
Integration Time				210 ms
Quantities Recorded in Each Cell		Doppler Spectra,
						Cross Section,
						Doppler Offset,
						Doppler Bandwidth

ROTATING MODE:

Antenna Rotation Rate				15 rpm
Antenna Length					2 feet
Antenna Width					5 inches each (HH & VV)
Vertical Beamwidth, One Way, 3-dB, Full		25 degrees
Horizontal Beamwidth, One Way, 3-dB, Full	4 degrees
Pulse Width					50 ns
Time Between Polarization Switching		340 ms

Configuration 1:
  Mean Antenna Incidence Angle			55 degrees
  Flight Altitude				300 m
  Continuous Incidence Angle Range (Approx)	25 to 65 degrees
  Swath Width (Approx)				750 m

Configuration 2:				
  Mean Antenna Incidence Angle			75 degrees
  Flight Altitude				75 m
  Continuous Incidence Angle Range (Approx)	45 to 85 degrees
  Swath Width (Approx)				750 m


IMAGING MODE (SIDELOOKING):

Antenna Length					4 feet
Antenna Width					5 inches each (HH & VV)
Vertical Beamwidth, One Way, 3-dB, Full		25 degrees
Horizontal Beamwidth, One Way, 3-dB, Full	1.8 degrees
Time Between Polarization Switching		340 ms (VV and HH)
						Infinite (VV or HH)
Configuration 1:
  Mean Antenna Incidence Angle			60 degrees
  Flight Altitude				300 m
  Pulse Width					50 ns
  Continuous Incidence Angle Range (Approx)	30 to 70 degrees
  Swath Width (Approx)				1 km
  Ground-Range Resolution (Approx)		10 m
  Azimuthal Resolution (Approx @ 50 m/s)	15 m	

Configuration 2:
  Mean Antenna Incidence Angle			75 degrees
  Flight Altitude				75 m
  Pulse Width					50 ns
  Continuous Incidence Angle Range (Approx)	40 to 85 degrees
  Swath Width (Approx)				1 km
  Ground-Range Resolution (Approx)		10 m
  Azimuthal Resolution (Approx @ 50 m/s)	11 m	

Configuration 3:
  Mean Antenna Incidence Angle			60 degrees
  Flight Altitude				1200 m
  Pulse Width					200 ns
  Continuous Incidence Angle Range (Approx)	30 to 70 degrees
  Swath Width (Approx)				4 km
  Ground-Range Resolution (Approx)		40 m
  Azimuthal Resolution (Approx)			40 m	



FAST POLARIZATION SWITCHING MODE:

Any of the three imaging configurations but with the rotating 
mode disabled.   This mode allows polarization switching at rates 
much higher than the decorrelation rate of sea surface return.