eccodes/examples/C/bufr_read_synop.c

124 lines
4.2 KiB
C

/*
* (C) Copyright 2005- ECMWF.
*
* This software is licensed under the terms of the Apache Licence Version 2.0
* which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
*
* In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
* virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
*/
/*
* C Implementation: bufr_read_synop
*
* Description: how to read SYNOP BUFR messages.
*
*/
/*
* Please note that SYNOP reports can be encoded in various ways in BUFR. Therefore the code
* below might not work directly for other types of SYNOP messages than the one used in the
* example. It is advised to use bufr_dump to understand the structure of the messages.
*/
#include "eccodes.h"
int main(int argc, char* argv[])
{
FILE* in = NULL;
/* message handle. Required in all the eccodes calls acting on a message.*/
codes_handle* h = NULL;
long longVal;
double doubleVal;
int err = 0;
int cnt = 0;
const char* infile = "../../data/bufr/syno_multi.bufr";
in = fopen(infile, "rb");
if (!in) {
fprintf(stderr, "Error: unable to open file %s\n", infile);
return 1;
}
/* loop over the messages in the BUFR file */
while ((h = codes_handle_new_from_file(NULL, in, PRODUCT_BUFR, &err)) != NULL || err != CODES_SUCCESS) {
if (h == NULL) {
fprintf(stderr, "Error: unable to create handle for message %d\n", cnt);
cnt++;
continue;
}
printf("message: %d\n", cnt);
/* we need to instruct ecCodes to unpack the data values */
CODES_CHECK(codes_set_long(h, "unpack", 1), 0);
/* station id*/
CODES_CHECK(codes_get_long(h, "blockNumber", &longVal), 0);
printf(" blockNumber: %ld\n", longVal);
CODES_CHECK(codes_get_long(h, "stationNumber", &longVal), 0);
printf(" stationNumber: %ld\n", longVal);
/* location*/
CODES_CHECK(codes_get_double(h, "latitude", &doubleVal), 0);
printf(" latitude: %f\n", doubleVal);
CODES_CHECK(codes_get_double(h, "longitude", &doubleVal), 0);
printf(" longitude: %f\n", doubleVal);
/* 2m temperature */
CODES_CHECK(codes_get_double(h, "airTemperatureAt2M", &doubleVal), 0);
printf(" airTemperatureAt2M: %f\n", doubleVal);
/* 2m dewpoint temperature */
CODES_CHECK(codes_get_double(h, "dewpointTemperatureAt2M", &doubleVal), 0);
printf(" dewpointTemperatureAt2M: %f\n", doubleVal);
/* 10 wind */
CODES_CHECK(codes_get_double(h, "windSpeedAt10M", &doubleVal), 0);
printf(" windSpeedAt10M: %f\n", doubleVal);
CODES_CHECK(codes_get_double(h, "windDirectionAt10M", &doubleVal), 0);
printf(" windDirectionAt10M: %f\n", doubleVal);
/* The cloud information is stored in several blocks in the
* SYNOP message and the same key means a different thing in different
* parts of the message. In this example we will read the first
* cloud block introduced by the key
* verticalSignificanceSurfaceObservations=1.
* We know that this is the first occurrence of the keys we want to
* read so we will use the # (occurrence) operator accordingly. */
/* Cloud amount (low and middleclouds) */
CODES_CHECK(codes_get_long(h, "#1#cloudAmount", &longVal), 0);
printf(" cloudAmount (low and middle): %ld\n", longVal);
/* Height of cloud base */
CODES_CHECK(codes_get_long(h, "#1#heightOfBaseOfCloud", &longVal), 0);
printf(" heightOfBaseOfCloud: %ld\n", longVal);
/* Cloud type (low clouds) */
CODES_CHECK(codes_get_long(h, "#1#cloudType", &longVal), 0);
printf(" cloudType (low): %ld\n", longVal);
/* Cloud type (middle clouds) */
CODES_CHECK(codes_get_long(h, "#2#cloudType", &longVal), 0);
printf(" cloudType (middle): %ld\n", longVal);
/* Cloud type (high clouds) */
CODES_CHECK(codes_get_long(h, "#3#cloudType", &longVal), 0);
printf(" cloudType (high): %ld\n", longVal);
/* delete handle */
codes_handle_delete(h);
cnt++;
}
fclose(in);
return 0;
}