void xrit_orientation(int orientation)
int read_xrit(const char *filename, uint16_t *counts, int *isegment, xrit_header_t **xrit_header, xrit_rows_infos_t *rows_infos, MSG_Prologue *prologue, MSG_Epilogue *epilogue)
void free_xrit_header(xrit_header_t *xrit_header)
void print_xrit_header(xrit_header_t *xrit_header)
This function should be called BEFORE any call to the read_xrit routine. It sets the orientation of the image which will be loaded by read_xrit.
orientation may be given the values : XRIT_NORTH_AT_TOP, XRIT_SOUTH_AT_TOP
The default is XRIT_SOUTH_AT_TOP (for this is the original orientation of the data)
This function loads the filename's content into the counts buffer. The file is expected to be an MSG/SEVIRI XRIT radiances file (the counts are 16-bit unsigned integral values in linear relationship with radiances, the conversion coefficients may be retrieved from the prologue)
filename: the name of the XRIT file to read
counts: the buffer to be filled by the routine. Must be allocated by the caller (with XRIT_NROWS*XRIT_NCOLUMNS elements of type uint16_t)
isegment: a pointer to an int that will be filled with the index of segment to extract (between 1 and 8). To extract all the segments, set *isegment to 0 or isegment to NULL.
xrit_header: a linked list containing the headers for each segment. Allocated by read_xrit (give only the address of a pointer of type xrit_header_t *, or NULL to ignore this parameter). These headers may be displayed with print_xrit_header.
rows_infos: a structure that contains time and validity infos for each row of data. Must be allocated by the caller (or set to NULL to ignore it). The xrit_rows_infos_t structure is defined in the read_xrit.h file.
prologue: a pointer to an MSG_Prologue structure, that must be allocated by the caller or set to NULL. The structure will be filled by the routine if the pointer is not NULL.
epilogue: a pointer to an MSG_Epilogue structure, that must be allocated by the caller or set to NULL. The structure will be filled by the routine if the pointer is not NULL (currently not implemented, so use NULL for the time being).
frees any xrit_header linked list allocated and filled by read_xrit
a debugging purpose function that prints infos about headers found in an XRIT file. Must be given an xrit_header returned by read_xrit
This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
The MSG_Epilogue structure is not implemented yet. The epilogue argument in read_xrit must be given a NULL value.
The radiometric_validity and geometric_validity fields in the xrit_rows_infos_t structure are not reliable. It seems they are not always correctly recorded in the XRIT files.
Please report any bug you could find to contact@icare.univ-lille1.fr