Single Look Comlex Data Description

	For SIR-C  there are three possible data formats:

		1) compressed cross-products data (MLC)  (Multilook data)
			 quad-pol, 10 bytes per pixel
		 	 dual-pol 5 bytes per pixel 

		2) compressed detected data (MLD)  (Multilook data)
			 single-pol, 2 bytes per pixel

		3) compressed scattering matrix data (SLC)  (Singlelook data)
			 quad-pol, 10 bytes per pixel
			 dual-pol, 6 bytes per pixel
			 single-pol, 4 bytes per pixel 

	In the following descriptions:
	
		sign( ) will return the sign of the argument ( ± 1) 

		nint( ) will indicate that the nearest integer value is calculated of its 
argument.  

		int( ) will indicate that the truncation of the floating point value to integer 
is calculated of its argument, and that, if the floating point value is less than zero, 
subtraction by 1.0 is additionally required.  Note that this is not the same as FORTRAN 
int( ).



Single Look Complex data


	There are three data products for complex scattering matrix data, depending of 
polarization mode.


	SIR-C "SLC" quad-pol data - 10 bytes per pixel.  Consists of one file for each 
scene, per frequency.  Each line of the file consists of TBD range samples, in which range 
increases with sample number.  There are a TBD number of lines per file, in which each 
line corresponds to different azimuth or along track locations.  There are no header lines 
after the file has been stripped for the header by the CEOS reader.   The standard output 
product by the GDPS will not have 12 bytes of file information at the beginning of each 
line.  There will be separate header files.  This data will be single look complex scattering 
matrix data.  This is the only format that is supported by the SIR-C calibration processor 
during phase 1.  There is no symmetrization of the data.  There is no general scale factor.

¡ 10 bytes per pixel - quad-pol data, with:
	¡ Byte(1) :  int{log2 (SHHSHH* + SHVSHV* + SVHSVH*+ SVVSVV*)}
	¡ Byte(2) : nint{254[Mantissa  - 1.5]}

		Mantissa =  (SHHSHH* + SHVSHV* + SVHSVH*+ SVVSVV*) / 
2Byte(1)
		qsca =  sqrt{ [ (Byte(2) / 254 ) + 1.5] 2Byte(1) }

	¡ Byte(3) : nint{127 Re(SHH)/qsca}
	¡ Byte(4) : nint{127 Im(SHH)/qsca}
 	¡ Byte(5) : nint{127 Re(SHV)/qsca}
	¡ Byte(6) : nint{127 Im(SHV)/qsca}
	¡ Byte(7) : nint{127 Re(SVH)/qsca}
	¡ Byte(8) : nint{127 Im(SVH)/qsca}
	¡ Byte(9) : nint{127 Re(SVV)/qsca}
	¡ Byte(10) : nint{127 Im(SVV)/qsca}

	 The total power (when  decompressing) is :

		TP =  0.25 ( byte(2) / 254 + 1.5) 2Byte(1)) 

	and the remaining terms are given by :

		ysca =  sqrt{ [ (Byte(2) / 254 ) + 1.5] 2Byte(1) }

		Re(SHH) = byte(3) ysca/127
		Im(SHH) = byte(4) ysca/127
		Re(SHV) = byte(5) ysca/127
		Im(SHV) = byte(6) ysca/127
		Re(SVH) = byte(7) ysca/127
		Im(SVH) = byte(8) ysca/127
		Re(SVV) = byte(9) ysca/127
		Im(SVV) = byte(10) ysca/127


	SIR-C "SLC" dual-pol data - 6 bytes per pixel.  Consists of one file for each 
scene, per frequency.  Each line of the file consists of TBD range samples, in which range 
increases with sample number.  There are a TBD number of lines per file, in which each 
line corresponds to different azimuth or along track locations.  There are no header lines 
after the file has been stripped for the header by the CEOS reader. The standard output 
product by the GDPS will not have 12 bytes of file information at the beginning of each 
line.  There will be separate header files.  This data will be single look complex scattering 
matrix data.  The compression format is the same as for the quad-pol data format, except 
that not all 10 bytes are present.  The bytes present depend on the polarization mode.
	HH and VV polarizations : bytes 1,2,3,4,9,10
	HH and HV polarizations : bytes 1,2,3,4,5,6
	VH and VV polarizations : bytes 1,2,7,8,9,10

	SIR-C "SLC" single-pol data - 4 bytes per pixel.  Consists of one file for each 
scene, per frequency.  Each line of the file consists of TBD range samples, in which range 
increases with sample number.  There are a TBD number of lines per file, in which each 
line corresponds to different azimuth or along track locations.  There are no header lines 
after the file has been stripped for the header by the CEOS reader. The standard output 
product by the GDPS will have 12 bytes of file information at the beginning of each line.  
There will be separate header files.  This data will be single look complex scattering 
matrix data.  The compression format is the same as for the quad-pol data format, except 
that not all 10 bytes are present.  The bytes present depend on the polarization mode.

	HH polarization : bytes 1,2,3,4
	VV polarization : bytes 1,2,9,10