// Determine radiometrically correction amplitude value
float get_rad_cal_dn(meta_parameters *meta, int line, int sample, char *bandExt,
float inDn, float radCorr)
{
// Return background value unchanged
if (FLOAT_EQUIVALENT(inDn, 0.0))
return 0.0;
meta->general->radiometry = r_SIGMA;
double incid = meta_incid(meta, line, sample);
double sigma = get_cal_dn(meta, incid, sample, inDn, bandExt, FALSE);
double calValue, invIncAngle;
// Calculate according to the calibration data type
if (meta->calibration->type == asf_cal) { // ASF style data (PP and SSP)
asf_cal_params *p = meta->calibration->asf;
double index = (double)sample*256./(double)(p->sample_count);
int base = (int) index;
double frac = index - base;
double *noise = p->noise;
// Determine the noise value
double noiseValue = noise[base] + frac*(noise[base+1] - noise[base]);
// Convert (amplitude) data number to scaled, noise-removed power
//scaledPower = (p->a1*(inDn*inDn-p->a0*noiseValue) + p->a2)*invIncAngle;
calValue = sqrt(((sigma * radCorr) - p->a2)/p->a1 + p->a0*noiseValue);
}
else if (meta->calibration->type == asf_scansar_cal) { // ASF style ScanSar
invIncAngle = 1.0;
asf_scansar_cal_params *p = meta->calibration->asf_scansar;
double look = 25.0; // FIXME: hack to get things compiled
double index = (look-16.3)*10.0;
double noiseValue;
double *noise = p->noise;
if (index <= 0)
noiseValue = noise[0];
else if (index >= 255)
noiseValue = noise[255];
else {
// Use linear interpolation on noise array
int base = (int)index;
double frac = index - base;
noiseValue = noise[base] + frac*(noise[base+1] - noise[base]);
}
// Convert (amplitude) data number to scaled, noise-removed power
//scaledPower = (p->a1*(inDn*inDn-p->a0*noiseValue) + p->a2)*invIncAngle;
calValue = sqrt(((sigma * radCorr) - p->a2)/p->a1 + p->a0*noiseValue);
}
else if (meta->calibration->type == esa_cal) { // ESA style ERS and JERS data
esa_cal_params *p = meta->calibration->esa;
//scaledPower = inDn*inDn/p->k*sin(p->ref_incid*D2R)/sin(incid);
calValue = sqrt(sigma * radCorr * p->k*sin(p->ref_incid*D2R)*sin(incid));
}
else if (meta->calibration->type == rsat_cal) { // CDPF style Radarsat data
invIncAngle = 1/tan(incid);
rsat_cal_params *p = meta->calibration->rsat;
double a2;
if (meta->calibration->rsat->focus)
a2 = p->lut[0];
else if (sample < (p->samp_inc*(p->n-1))) {
int i_low = sample/p->samp_inc;
int i_up = i_low + 1;
a2 = p->lut[i_low] +
((p->lut[i_up] - p->lut[i_low])*((sample/p->samp_inc) - i_low));
}
else
a2 = p->lut[p->n-1] +
((p->lut[p->n-1] - p->lut[p->n-2])*((sample/p->samp_inc) - p->n-1));
if (p->slc)
//scaledPower = (inDn*inDn)/(a2*a2)*invIncAngle;
calValue = sqrt(sigma * radCorr *a2*a2/invIncAngle);
else
//scaledPower = (inDn*inDn + p->a3)/a2*invIncAngle;
calValue = sqrt((sigma * radCorr *a2/invIncAngle) - p->a3);
}
else if (meta->calibration->type == alos_cal) { // ALOS data
alos_cal_params *p = meta->calibration->alos;
double cf;
if (strstr(bandExt, "HH"))
cf = p->cf_hh;
else if (strstr(bandExt, "HV"))
cf = p->cf_hv;
else if (strstr(bandExt, "VH"))
cf = p->cf_vh;
else if (strstr(bandExt, "VV"))
cf = p->cf_vv;
//scaledPower = pow(10, cf/10.0)*inDn*inDn*invIncAngle;
calValue = sqrt(sigma * radCorr / pow(10, cf/10.0));
}
else if (meta->calibration->type == tsx_cal) {
invIncAngle = 1/tan(incid);
double cf = meta->calibration->tsx->k;
//scaledPower = cf*inDn*inDn*invIncAngle;
calValue = sqrt(sigma * radCorr / (cf*invIncAngle));
}
return calValue;
}
int asf_calibrate(const char *inFile, const char *outFile,
radiometry_t outRadiometry, int wh_scaleFlag)
{
meta_parameters *metaIn = meta_read(inFile);
meta_parameters *metaOut = meta_read(inFile);
if (!metaIn->calibration) {
asfPrintError("This data cannot be calibrated, missing calibration block.\n");
}
// Check for valid output radiometry
if (outRadiometry == r_AMP || outRadiometry == r_POWER)
asfPrintError("Invalid radiometry (%s) passed into calibration function!\n",
radiometry2str(outRadiometry));
// Check whether output radiometry fits with Woods Hole scaling flag
if (wh_scaleFlag && outRadiometry >= r_SIGMA && outRadiometry <= r_GAMMA)
outRadiometry += 3;
// This can only work if the image is in some SAR geometry
if (metaIn->projection && metaIn->projection->type != SCANSAR_PROJECTION)
asfPrintError("Can't apply calibration factors to map projected images\n"
"(Amplitude or Power only)\n");
radiometry_t inRadiometry = metaIn->general->radiometry;
asfPrintStatus("Calibrating %s image to %s image\n\n",
radiometry2str(inRadiometry), radiometry2str(outRadiometry));
// FIXME: This function should be able to remap between different
// radiometry projections.
if (metaIn->general->radiometry != r_AMP)
asfPrintError("Currently only AMPLITUDE as radiometry is supported!\n");
metaOut->general->radiometry = outRadiometry;
int dbFlag = FALSE;
if (outRadiometry >= r_SIGMA && outRadiometry <= r_GAMMA)
metaOut->general->no_data = 0.0001;
if (outRadiometry >= r_SIGMA_DB && outRadiometry <= r_GAMMA_DB) {
metaOut->general->no_data = -40.0;
dbFlag = TRUE;
}
if (metaIn->general->image_data_type != POLARIMETRIC_IMAGE) {
if (outRadiometry == r_SIGMA || outRadiometry == r_SIGMA_DB)
metaOut->general->image_data_type = SIGMA_IMAGE;
else if (outRadiometry == r_BETA || outRadiometry == r_BETA_DB)
metaOut->general->image_data_type = BETA_IMAGE;
else if (outRadiometry == r_GAMMA || outRadiometry == r_GAMMA_DB)
metaOut->general->image_data_type = GAMMA_IMAGE;
}
if (wh_scaleFlag)
metaOut->general->data_type = ASF_BYTE;
char *input = appendExt(inFile, ".img");
char *output = appendExt(outFile, ".img");
FILE *fpIn = FOPEN(input, "rb");
FILE *fpOut = FOPEN(output, "wb");
int dualpol = strncmp_case(metaIn->general->mode, "FBD", 3) == 0 ? 1 : 0;
int band_count = metaIn->general->band_count;
int sample_count = metaIn->general->sample_count;
int line_count = metaIn->general->line_count;
char **bands =
extract_band_names(metaIn->general->bands, band_count);
float *bufIn = (float *) MALLOC(sizeof(float)*sample_count);
float *bufOut = (float *) MALLOC(sizeof(float)*sample_count);
float *bufIn2 = NULL, *bufOut2 = NULL, *bufOut3 = NULL;
if (dualpol && wh_scaleFlag) {
bufIn2 = (float *) MALLOC(sizeof(float)*sample_count);
bufOut2 = (float *) MALLOC(sizeof(float)*sample_count);
bufOut3 = (float *) MALLOC(sizeof(float)*sample_count);
metaOut->general->band_count = 3;
sprintf(metaOut->general->bands, "%s,%s,%s-%s",
bands[0], bands[1], bands[0], bands[1]);
}
int ii, jj, kk;
float cal_dn, cal_dn2;
double incid;
if (dualpol && wh_scaleFlag) {
metaOut->general->image_data_type = RGB_STACK;
for (ii=0; ii<line_count; ii++) {
get_band_float_line(fpIn, metaIn, 0, ii, bufIn);
get_band_float_line(fpIn, metaIn, 1, ii, bufIn2);
for (jj=0; jj<sample_count; jj++) {
// Taking the remapping of other radiometries out for the moment
//if (inRadiometry >= r_SIGMA && inRadiometry <= r_BETA_DB)
//bufIn[jj] = cal2amp(metaIn, incid, jj, bands[kk], bufIn[jj]);
incid = meta_incid(metaIn, ii, jj);
cal_dn =
get_cal_dn(metaOut, incid, jj, bufIn[jj], bands[0], dbFlag);
cal_dn2 =
get_cal_dn(metaOut, incid, jj, bufIn2[jj], bands[1], dbFlag);
if (FLOAT_EQUIVALENT(cal_dn, metaIn->general->no_data) ||
cal_dn == cal_dn2) {
bufOut[jj] = 0;
bufOut2[jj] = 0;
bufOut3[jj] = 0;
}
else {
bufOut[jj] = (cal_dn + 31) / 0.15 + 1.5;
bufOut2[jj] = (cal_dn2 + 31) / 0.15 + 1.5;
bufOut3[jj] = bufOut[jj] - bufOut2[jj];
}
}
put_band_float_line(fpOut, metaOut, 0, ii, bufOut);
put_band_float_line(fpOut, metaOut, 1, ii, bufOut2);
put_band_float_line(fpOut, metaOut, 2, ii, bufOut3);
asfLineMeter(ii, line_count);
}
}
else {
for (kk=0; kk<band_count; kk++) {
for (ii=0; ii<line_count; ii++) {
get_band_float_line(fpIn, metaIn, kk, ii, bufIn);
for (jj=0; jj<sample_count; jj++) {
// Taking the remapping of other radiometries out for the moment
//if (inRadiometry >= r_SIGMA && inRadiometry <= r_BETA_DB)
//bufIn[jj] = cal2amp(metaIn, incid, jj, bands[kk], bufIn[jj]);
if (strstr(bands[kk], "PHASE") == NULL) {
incid = meta_incid(metaIn, ii, jj);
cal_dn =
get_cal_dn(metaOut, incid, jj, bufIn[jj], bands[kk], dbFlag);
if (wh_scaleFlag) {
if (FLOAT_EQUIVALENT(cal_dn, metaIn->general->no_data))
bufOut[jj] = 0;
else
bufOut[jj] = (cal_dn + 31) / 0.15 + 1.5;
}
else
bufOut[jj] = cal_dn;
}
else // PHASE band, do nothing
bufOut[jj] = bufIn[jj];
}
put_band_float_line(fpOut, metaOut, kk, ii, bufOut);
asfLineMeter(ii, line_count);
}
if (kk==0)
sprintf(metaOut->general->bands, "%s-%s",
radiometry2str(outRadiometry), bands[kk]);
else {
char tmp[255];
sprintf(tmp, ",%s-%s", radiometry2str(outRadiometry), bands[kk]);
strcat(metaOut->general->bands, tmp);
}
}
}
meta_write(metaOut, outFile);
meta_free(metaIn);
meta_free(metaOut);
FREE(bufIn);
FREE(bufOut);
if (dualpol) {
FREE(bufIn2);
FREE(bufOut2);
FREE(bufOut3);
}
for (kk=0; kk<band_count; ++kk)
FREE(bands[kk]);
FREE(bands);
FCLOSE(fpIn);
FCLOSE(fpOut);
FREE(input);
FREE(output);
return FALSE;
}
