const struct {
    float d[4][3];
    struct {
        float vc, A, B;
    } rad[3];
    struct {
        float Ns;
        float b[3];
    } cor[3];
} satcal[4] =
{/* calibration coeff from NOAA KLM POES satellite user guide */
{/* NOAA-15 */
{ /* PRT coeff d0,d1,d2 */
{276.60157 , 0.051045 , 1.36328E-06},
{276.62531 , 0.050909 , 1.47266E-06},
{276.67413 , 0.050907 , 1.47656E-06},
{276.59258 , 0.050966 , 1.47656E-06}
},
{ /* channel radiance coeff vc,A,B*/
{925.4075 , 0.337810 , 0.998719}, /* channel 4 */
{839.8979 , 0.304558 , 0.999024}, /* channel 5 */
{2695.9743 , 1.621256 , 0.998015} /* channel 3B */
},
{ /*  nonlinear radiance correction Ns,b0,b1,b2 */
{-4.50 , {4.76 , -0.0932 , 0.0004524}}, /* channel 4 */
{-3.61 , {3.83 , -0.0659 , 0.0002811}},  /* channel 5*/
{0.0,{0.0,0.0,0.0}}  /* channel 3B*/
}
},
{/* NOAA-16 */
{ /* PRT coeff d0,d1,d2 */
{276.355 , 5.562E-02 ,-1.590E-05},
{276.142 , 5.605E-02 ,-1.707E-05},
{275.996 , 5.486E-02 ,-1.223E-05},
{276.132 , 5.494E-02 ,-1.344E-05}
},
{ /* channel radiance coeff vc,A,B*/
{917.2289 ,0.332380 ,0.998522}, /* channel 4 */
{838.1255 ,0.674623 ,0.998363}, /* channel 5 */
{2700.1148 ,1.592459,0.998147} /* channel 3B */
},
{ /*  nonlinear radiance correction Ns,b0,b1,b2 */
{-2.467, {2.96,-0.05411,0.00024532}}, /* channel 4 */
{-2.009,{2.25,-0.03665,0.00014854}}, /* channel 5*/
{0.0,{0.0,0.0,0.0}}  /* channel 3B*/
}
},
{/* NOAA 17 */
{ /* PRT coeff d0,d1,d2 */
{276.628 , 0.05098 , 1.371e-06},
{276.538 , 0.05098 , 1.371e-06},
{276.761 , 0.05097 , 1.369e-06},
{276.660 , 0.05100 , 1.348e-06}
},
{ /* channel radiance coeff vc,A,B*/
{926.2947 , 0.271683 , 0.998794}, /* channel 4 */
{839.8246 , 0.309180 , 0.999012}, /* channel 5 */
{2669.3554 , 1.702380 , 0.997378} /* channel 3B */
},
{ /*  nonlinear radiance correction Ns,b0,b1,b2 */
{-8.55 , {8.22 , -0.15795 , 0.00075579}}, /* channel 4 */
{-3.97 , {4.31 , -0.07318 , 0.00030976}}, /* channel 5 */
{0.0,{0.0,0.0,0.0}}  /* channel 3B*/
}
},
{/* NOAA 18 */
{ /* PRT coeff d0,d1,d2 */
{276.601 , 0.05090 , 1.657e-06},
{276.683 , 0.05101 , 1.482e-06},
{276.565 , 0.05117 , 1.313e-06},
{276.615 , 0.05103 , 1.484e-06}
},
{ /* channel radiance coeff vc,A,B*/
{928.1460 , 0.436645 , 0.998607}, /* channel 4 */
{833.2532 , 0.253179 , 0.999057}, /* channel 5 */
{2659.7952 , 1.698704 , 0.996960} /* channel 3B */
},
{ /*  nonlinear radiance correction Ns,b0,b1,b2 */
{-5.53 , {5.82 , -0.11069 , 0.00052337}}, /* channel 4 */
{-2.22 , {2.67 , -0.04360 , 0.00017715}}, /* channel 5 */
{0.0,{0.0,0.0,0.0}}  /* channel 3B*/
}
}
};


const float c1=1.1910427e-5;
const float c2=1.4387752;