Circular Polarization Degree

From a pair of (R+L) and (R-L) images of 17 GHz, distribution of circluar polarization degree can be obtained. It is used for judging the emission mechanism and/or deriving the magnetic field strength. The definition is;

$$r_{c} \equiv {F_{\nu}^{(R-L)}\over F_{\nu}^{(R+L)}} = {T_{b}^{(R-L)}\over T_{b}^{(R+L)}}$$

Minimum is -1 (perfectly left-handed circular polarized), and maximum is +1 (perfectly right-handed circular polarized). The procedure is :
IDL> file='./ipa990828_005642' $<$CR$>$
IDL> norh_rd_img,file,indexa,dataa $<$CR$>$
IDL> file='./ips990828_005642' $<$CR$>$
IDL> norh_rd_img,file,indexs,datas $<$CR$>$
IDL> fi17=norh_tb2flux(dataa,indexa,/intensity) $<$CR$>$
IDL> fv17=norh_tb2flux(datas,indexs,/intensity) $<$CR$>$
IDL> norh_polariz,indexa,fi17,indexs,fv17,indexp,pol,mvdp $<$CR$>$
pol is an array of $r_{c}$. mvdp is an array including the values of unity (1) for valid data or zero (0) for non-valid data. indexp is an index correspoinding to data pol.