/* * Atpdec * Copyright (c) 2004 by Thierry Leconte (F4DWV) * * $Id$ * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Library General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #define REGORDER 3 typedef struct { double cf[REGORDER + 1]; } rgparam; static void rgcomp(double x[16], rgparam * rgpr) { /*{ 0.106,0.215,0.324,0.433,0.542,0.652,0.78,0.87 ,0.0 }; */ const double y[9] = { 31.07, 63.02, 94.96, 126.9, 158.86, 191.1, 228.62, 255.0, 0.0 }; extern void polyreg(const int m, const int n, const double x[], const double y[], double c[]); polyreg(REGORDER, 9, x, y, rgpr->cf); } static double rgcal(float x, rgparam * rgpr) { double y, p; int i; for (i = 0, y = 0.0, p = 1.0; i < REGORDER + 1; i++) { y += rgpr->cf[i] * p; p = p * x; } return (y); } static double tele[16]; static double Cs; static int nbtele; int Calibrate(float **prow, int nrow, int offset) { double teleline[3000]; double wedge[16]; rgparam regr[30]; int n; int k; int mtelestart, telestart; int channel = -1; float max; printf("Calibration ... "); fflush(stdout); /* build telemetry values lines */ for (n = 0; n < nrow; n++) { int i; teleline[n] = 0.0; for (i = 3; i < 43; i++) { teleline[n] += prow[n][i + offset + 956]; } teleline[n] /= 40.0; } if (nrow < 192) { fprintf(stderr, " impossible, not enought row\n"); return (0); } /* find telemetry start in the 2nd third */ max = 0.0; mtelestart = 0; for (n = nrow / 3 - 64; n < 2 * nrow / 3 - 64; n++) { float df; df = (teleline[n - 4] + teleline[n - 3] + teleline[n - 2] + teleline[n - 1]) / (teleline[n] + teleline[n + 1] + teleline[n + 2] + teleline[n + 3]); if (df > max) { mtelestart = n; max = df; } } mtelestart -= 64; telestart = mtelestart % 128; if (mtelestart < 0 || nrow < telestart + 128) { fprintf(stderr, " impossible, not enought row\n"); return (0); } /* compute wedges and regression */ for (n = telestart, k = 0; n < nrow - 128; n += 128, k++) { int j; for (j = 0; j < 16; j++) { int i; wedge[j] = 0.0; for (i = 1; i < 7; i++) wedge[j] += teleline[n + j * 8 + i]; wedge[j] /= 6; } rgcomp(wedge, &(regr[k])); if (k == nrow / 256) { int i, l; /* telemetry calibration */ for (j = 0; j < 16; j++) { tele[j] = rgcal(wedge[j], &(regr[k])); } /* channel ID */ for (j = 0, max = 10000.0, channel = -1; j < 6; j++) { float df; df = wedge[15] - wedge[j]; df = df * df; if (df < max) { channel = j; max = df; } } /* Cs computation */ for (Cs = 0.0, i = 0, j = n; j < n + 128; j++) { double csline; for (csline = 0.0, l = 3; l < 43; l++) csline += prow[n][l + offset]; csline /= 40.0; if (csline > 50.0) { Cs += csline; i++; } } Cs /= i; Cs = rgcal(Cs, &(regr[k])); } } nbtele = k; /* calibrate */ for (n = 0; n < nrow; n++) { float *pixelv; int i; pixelv = prow[n]; for (i = 0; i < 1001; i++) { float pv; int k, kof; pv = pixelv[i + offset]; k = (n - telestart) / 128; if (k >= nbtele) k = nbtele - 1; kof = (n - telestart) % 128; if (kof < 64) { if (k < 1) { pv = rgcal(pv, &(regr[k])); } else { pv = rgcal(pv, &(regr[k])) * (64 + kof) / 128.0 + rgcal(pv, &(regr[k - 1])) * (64 - kof) / 128.0; } } else { if ((k + 1) >= nbtele) { pv = rgcal(pv, &(regr[k])); } else { pv = rgcal(pv, &(regr[k])) * (192 - kof) / 128.0 + rgcal(pv, &(regr[k + 1])) * (kof - 64) / 128.0; } } if (pv > 255.0) pv = 255.0; if (pv < 0.0) pv = 0.0; pixelv[i + offset] = pv; } } printf("Done\n"); return (channel); } /* ------------------------------temperature calibration -----------------------*/ extern int satnum; const struct { float d[4][3]; struct { float vc, A, B; } rad[3]; struct { float Ns; float b[3]; } cor[3]; } satcal[4] = #include "satcal.h" typedef struct { double Nbb; double Cs; double Cb; int ch; } tempparam; /* temperature compensation for IR channel */ static void tempcomp(double t[16], int ch, tempparam * tpr) { double Tbb, T[4]; double C; int n; tpr->ch = ch - 3; /* compute equivalent T black body */ for (n = 0; n < 4; n++) { float d0, d1, d2; C = t[9 + n] * 4.0; d0 = satcal[satnum].d[n][0]; d1 = satcal[satnum].d[n][1]; d2 = satcal[satnum].d[n][2]; T[n] = d0; T[n] += d1 * C; C = C * C; T[n] += d2 * C; } Tbb = (T[0] + T[1] + T[2] + T[3]) / 4.0; Tbb = satcal[satnum].rad[tpr->ch].A + satcal[satnum].rad[tpr->ch].B * Tbb; /* compute radiance Black body */ C = satcal[satnum].rad[tpr->ch].vc; tpr->Nbb = c1 * C * C * C / (exp(c2 * C / Tbb) - 1.0); /* store Count Blackbody and space */ tpr->Cs = Cs * 4.0; tpr->Cb = t[14] * 4.0; } static double tempcal(float Ce, tempparam * rgpr) { double Nl, Nc, Ns, Ne; double T, vc; Ns = satcal[satnum].cor[rgpr->ch].Ns; Nl = Ns + (rgpr->Nbb - Ns) * (rgpr->Cs - Ce * 4.0) / (rgpr->Cs - rgpr->Cb); Nc = satcal[satnum].cor[rgpr->ch].b[0] + satcal[satnum].cor[rgpr->ch].b[1] * Nl + satcal[satnum].cor[rgpr->ch].b[2] * Nl * Nl; Ne = Nl + Nc; vc = satcal[satnum].rad[rgpr->ch].vc; T = c2 * vc / log(c1 * vc * vc * vc / Ne + 1.0); T = (T - satcal[satnum].rad[rgpr->ch].A) / satcal[satnum].rad[rgpr->ch].B; /* rescale to range 0-255 for +40-60 °C */ T = (-T + 273.15 + 40) / 100.0 * 255.0; return (T); } void Temperature(float **prow, int nrow, int channel, int offset) { tempparam temp; int n; printf("Temperature ... "); fflush(stdout); tempcomp(tele, channel, &temp); for (n = 0; n < nrow; n++) { float *pixelv; int i; pixelv = prow[n]; for (i = 0; i < 1001; i++) { float pv; pv = tempcal(pixelv[i + offset], &temp); if (pv > 255.0) pv = 255.0; if (pv < 0.0) pv = 0.0; pixelv[i + offset] = pv; } } printf("Done\n"); }