/**
* Computes water vapour transmission for any band. Called by {@link #gas_correction}.
*
* <p>Reference: Level 2 DPM, step 2.6.12.3<br>
* Uses:<br>
* {@link L2AuxData#spectral_shift_H2Owavelength}, <br>
* {@link L2AuxData#H2OcoefSpecShift}, <br>
* {@link L2AuxData#H2Ocoef}, <br>
* {@link #H2OT_POLY_K} <br>
*
* @param ib band index
* @param R_h2o ratio rho(b15)/rho(b14)
* @param detector detector index
* @return h2o transmission in band ib
*/
private double trans_h2o(int ib, double R_h2o, int detector) {
double th2o, th2o_blw, th2o_abv;
int k;
if (ib == bb705)
/* if (FALSE) */ {
/* DPM #2.1.3-1,2,3,4-b900 */
Interp.interpCoord(
auxData.central_wavelength[bb705][detector],
auxData.spectral_shift_H2Owavelength,
lh.spectralShift705);
if (lh.spectralShift705.index == (PPOL_NUM_SHIFT - 1)) {
lh.spectralShift705.index = PPOL_NUM_SHIFT - 2;
lh.spectralShift705.fraction = 1.;
}
th2o_blw = 0.;
th2o_abv = 0.;
for (k = H2OT_POLY_K - 1; k >= 0; k--) {
th2o_blw =
R_h2o * th2o_blw
+ auxData.H2OcoefSpecShift[lh.spectralShift705.index][k]; /* DPM #2.6.12.3-2 */
th2o_abv =
R_h2o * th2o_abv
+ auxData.H2OcoefSpecShift[lh.spectralShift705.index + 1][k]; /* DPM #2.6.12.3-2 */
}
th2o =
(1. - lh.spectralShift705.fraction) * th2o_blw
+ (lh.spectralShift705.fraction) * th2o_abv;
} else {
th2o = 0.;
for (k = H2OT_POLY_K - 1; k >= 0; k--) {
th2o = R_h2o * th2o + auxData.H2Ocoef[ib][k]; /* DPM #2.6.12.3-2 */
}
}
return th2o;
}
/**
* Computes o2 transmission for band {@link #bb12}. Called by {@link #gas_correction}.
*
* <p>Reference: Level 2 DPM, step 2.6.12.2<br>
* Uses: {@link L2AuxData#central_wavelength} <br>
* {@link L2AuxData#spectral_shift_wavelength} <br>
* {@link L2AuxData#O2coef}<br>
* {@link #PPOL_NUM_SHIFT}<br>
* {@link #O2T_POLY_K}<br>
*
* @param ib band index (in case any other band is affected in the future)
* @param R_o2 ratio rho(b11)/rho(b10)
* @param detector detector index
* @return o2 transmission in band ib
*/
private double trans_o2(int ib, double R_o2, int detector) {
double to2;
if (ib == bb775) {
/* DPM #2.6.12.2-3, DPM #2.6.12.2-4, DPM #2.6.12.2-5, DPM #2.6.12.2-6 */
Interp.interpCoord(
auxData.central_wavelength[bb760][detector],
auxData.spectral_shift_wavelength,
lh.spectralShift760);
if (lh.spectralShift760.index == (PPOL_NUM_SHIFT - 1)) {
lh.spectralShift760.index = PPOL_NUM_SHIFT - 2;
lh.spectralShift760.fraction = 1.;
}
double to2_blw = 0.;
double to2_abv = 0.;
for (int k = O2T_POLY_K - 1; k >= 0; k--) {
/* DPM #2.6.12.3-2 */
to2_blw = R_o2 * to2_blw + auxData.O2coef[lh.spectralShift760.index][k];
/* DPM #2.6.12.3-2 */
to2_abv = R_o2 * to2_abv + auxData.O2coef[lh.spectralShift760.index + 1][k];
}
to2 =
(1. - lh.spectralShift760.fraction) * to2_blw + (lh.spectralShift760.fraction) * to2_abv;
} else {
to2 = 1.0; /* DPM #2.6.12.2-3 */
}
return to2;
}
