Data Set Overview : AIRSAR flew on NASA's DC-8 and acquired data at multiple incidence angles and azimuths over selected geological targets, such as sand dunes, volcanic fields, and alluvial fans. The GRSFE field areas overflown include the Lunar Crater Volcanic Field, Lunar Lake, Ubehebe Crater, and Death Valley. AIRSAR data consist of corrected Stokes matrices for the C, L, and P frequencies and data often exist for 2 or 3 incidence angles.  The complete complex scattering matrix (Stokes matrix) was measured using the instrument's two orthogonally polarized antennas, recording both the amplitude and absolute phase for each element in the image. Then, the Stokes matrix was corrected using the corner reflector data which have a known radar signature. This corrected Stokes matrix can be used to generate the scattering coefficient for any combination of transmit and receive antenna polarizations and can be processed to backscatter cross section or image formats with range and azimuth resolutions of approximately 20 meters.  Information regarding a software package that performs these manipulations, known as SYNTHESIZE, is included in the GRSFE CD-ROM collection.  Processing Level Id : 3 Software Flag : N Processing Start Time : 1989-09-15T00:00:00.000 Processing Stop Time : 1991-05-28T00:00:00.000   Parameters :  Data Set Parameter 'STOKES SCATTERING OPERATOR' ----------------------------------------------- Matrix element used to convert from one Stokes matrix to another. Used in image synthesis with AIRSAR polarimetric radar.  Data Set Parameter Name : STOKES SCATTERING OPERATOR Data Set Parameter Unit : DIMENSIONLESS Sampling Parameter Name : PIXEL Sampling Parameter Unit : METER Minimum Sampling Parameter : N/A Maximum Sampling Parameter : N/A Sampling Parameter Resolution : 25 Sampling Parameter Interval : 9 Minimum Available Sampling Int : 6 Noise Level : UNK   Source Instrument Parameters : Instrument Host ID : NDC8 Data Set Parameter Name : STOKES SCATTERING OPERATOR Instrument Parameter Name : RADAR ECHO POWER Important Instrument Parameters : 1   Measurement Information :  Atmospheric Conditions ---------------------- Not Applicable   Source ------ The radar observations were made using the airborne polarimetric SAR on NASA's DC-8 aircraft.   Calibration Standard -------------------- The responses from trihedral corner reflectors are used to calibrate the radar signal in each scene.   Wavelength Calibration ---------------------- Signals are derived from a stable local oscillator source operating at the L-band center frequency (1250 MHz). The P-band center frequency is derived from this source by down-converting, while the C-band center frequency is derived by up-converting.   Processing :  Processing History ------------------ Source Data Set ID : N/A Software : UNK Product Data Set ID : NDC8-E-ASAR-3-RDR-IMAGE-V1.0

Overview : Because of uncertainties in calibration procedures, absolute values are less well known than relative cross section values.