Gamma LAT: Reference Manual

quad2cp

ANSI-C program: quad2cp.c

NAME quad2cp -Synthesize Compact Polarization Data from quad-pol HH, VV, HV, VH SLC data

SYNOPSIS

quad2cp <SLC_HH> <SLC_HV> <SLC_VH> <SLC_VV> <SLC_HH_par> <SLC_HV_par> <SLC_VH_par> <SLC_VV_par> <CP> <TX_pol>

<SLC_HH>	(input) HH single-look complex image coregistered with SLC_HH (scomplex or fcomplex format)
<SLC_HV>	(input) HV single-look complex imagecoregistered with SLC_HH (scomplex or fcomplex format)
<SLC_VH>	(input) VH single-look complex image coregistered with SLC_HH (scomplex or fcomplex format)
<SLC_VV>	(input) VV single-look complex image coregistered with SLC_HH (scomplex or fcomplex format)
<SLC_HH_par>	(input) SLC_HH image parameter file
<SLC_HV_par>	(input) SLC_HV image parameter file
<SLC_VH_par>	(input) SLC_VH image parameter file
<SLC_VV_par>	(input) SLC_VV image parameter file
<CP>	(output) root file name of the 2 linearly polarized images (H,V): (fcomplex format) RCP transmit: _RH: 1/(sqrt(2) (S_HH - iS_HV) _RV: 1/(sqrt(2) (S_VH - iS_VV) LCP transmit: _LH: 1/(sqrt(2) (S_HH + iS_HV) _LV: 1/(sqrt(2) (S_VH + iS_VV) Note: SLC parameter files are created from the CP SLC name + .par
<TX_pol>	transmit polarization of synthesized compact mode data: 0: RCP Right Circular Polarziation 1: LCP Left Circular Polarziation

EXAMPLE

quad2cp 20080409_HH.slc
  20080409_HV.slc 20080409_VH.slc 20080409_VV.slc
  20080409_HH.slc.par 20080409_HV.slc.par 20080409_VH.slc.par
  20080409_VV.slc.par CP/20080409

1

Synthesizes compact polarization data with left circular polarized (LCP) illumination and linear H and V receive polarization. Input data are the 4 channels of a fully polarimetric data set. The output files are stored in the directory CP with SLC names 20080409_LH.slc and 20080409_LV.slc.

DESCRIPTION

Compact polarization data can be synthesized from quad-pol data sets [1]. Out of the different possible compact polarization configurations, circular polarized transmit with linear receive has been implemented on the Indian RISAT-1 satellite and will be used in the future Canadian Radarsat constellation.

Compact polarization has the advantage that single and double-bounce scattering mechanisms can be differentiated with just 2 polarization channels instead of the usual 4. quad2cp synthesizes data that would be received with circular polarization illumination illumination. The user can select the rotation sense of the illumination. With RCP transmit the output file names have _RH or _RV appended to the root file name. If LCP is selected then the extensions are _LH and LV respectively.

With RCP illumination calculation of the RH and RV are as follows:

RH: 1/sqrt(2) (S_HH - iS_HV)
RV: 1/sqrt(2) (S_VH - iS_VV)

For LCP illumination:

LH: 1/sqrt(2) (S_HH + iS_HV)
LV: 1/sqrt(2) (S_VH + iS_VV)

where S_* are the components of the complex valued scattering matrix for each sample.

[1] Cloude, S. R., D.G. Goodenough, H. Chen, "Compact Decomposition Theory," IEEE Geoscience and Remote Sensing Letters, Vol 9, No. 1, pp 28-32, January, 2012.

SEE ALSO

stokes, stokes_qm, m-chi