function cal_cds_psf_coeff_wave,lambda,X_PSF=X_PSF,Y_PSF=Y_PSF ;+ ;NAME: ; CAL_CDS_PSF_COEFF_WAVE ; Project: ; SOHO - CDS ; ;CREATED BY: David Christophe, IAS, march 1, 1999 ; ;CALLING SEQUENCE: ; C_L=cal_cds_psf_coeff_wave(lambda) ; ;PURPOSE: ; get the Point Spread Function in function of the ; wavelength. ; ;INPUTS: ; lambda : reference wavelength ; ;OUPUTS: ; C_L : The coefficients of the polynomial funtion describing the ; PSF (CDS telescope)in log-log scale. ; ; X_PSF : abscisse of PSF courbe for lambda (in arcsec) ; ; Y_PSF : value of PSF for lambda calculated with C_L polynomial ; coefficient. ; ; MODIFICATION HISTORY: ; David Christophe, IAS, jun 28, 1999 ; ;********************************************************************* ;********************************************************************* ;- C_L=fltarr(6) C_ref=[0.988441,-9.38801,6.13821,-2.73354,0.573765,-0.0449529] ;C_ref=[-2.25017,-2.63259,0,0,0,0] alpha=lambda/703. X_alpha=alog10(alpha) ; C_L(5)=C_ref(5) C_L(4)=(-5*X_alpha)*C_ref(5)+C_ref(4) C_L(3)=10*X_alpha^2*C_ref(5)-4*X_alpha*C_ref(4)+C_ref(3) C_L(2)=-10*X_alpha^3*C_ref(5)+6*X_alpha^2*C_ref(4)-3*X_alpha*C_ref(3)+C_ref(2) C_L(1)=5*X_alpha^4*C_ref(5)-4*X_alpha^3*C_ref(4)+3*X_alpha^2*C_ref(3)-2*X_alpha*C_ref(2)+C_ref(1) C_L(0)=-X_alpha^5*C_ref(5)+X_alpha^4*C_ref(4)-X_alpha^3*C_ref(3)+X_alpha^2*C_ref(2)-X_alpha*C_ref(1)+C_ref(0)-4*X_alpha ; X_LOGPSF=((findgen(10000)*(3.7-1)/9999.)+1) Y_PSF=10^poly(X_logPSF,C_L) X_PSF=10^X_logPSF return,C_L end