Description
This example shows: how to read SYNOP BUFR messages.
Source code
bufr_read_synop.f90
! ! (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. ! ! ! FORTRAN 90 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 first to understand the structure of these messages. ! ! program bufr_read_synop use eccodes implicit none integer :: ifile integer :: iret integer :: ibufr integer :: count=0 integer(kind=4) :: blockNumber,stationNumber real(kind=8) :: lat,t2m,td2m,ws,wdir integer(kind=4) :: cloudAmount,cloudBaseHeight,lowCloud,midCloud,highCloud call codes_open_file(ifile,'../../data/bufr/syno_multi.bufr','r') ! The first bufr message is loaded from file, ! ibufr is the bufr id to be used in subsequent calls call codes_bufr_new_from_file(ifile,ibufr,iret) do while (iret/=CODES_END_OF_FILE) write(*,*) 'message: ',count ! We need to instruct ecCodes to expand all the descriptors ! i.e. unpack the data values call codes_set(ibufr,"unpack",1) !read and print some data values. This example was written ! for a SYNOP BUFR file! ! wmo block number call codes_get(ibufr,'blockNumber',blockNumber) write(*,*) ' blockNumber:',blockNumber ! station number call codes_get(ibufr,'stationNumber',stationNumber) write(*,*) ' stationNumber:',stationNumber ! location call codes_get(ibufr,'latitude',lat) write(*,*) ' latitude:',lat call codes_get(ibufr,'longitude',lat) write(*,*) ' longitude:',lat ! 2m temperature call codes_get(ibufr,'airTemperatureAt2M',t2m); write(*,*) ' airTemperatureAt2M:',t2m ! 2m dewpoint temperature call codes_get(ibufr,'dewpointTemperatureAt2M',td2m); write(*,*) ' dewpointTemperatureAt2M:',td2m ! 10m wind call codes_get(ibufr,'windSpeedAt10M',ws); write(*,*) ' windSpeedAt10M:',ws call codes_get(ibufr,'windDirectionAt10M',wdir); write(*,*) ' windDirectionAt10M:',wdir ! 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) call codes_get(ibufr,'#1#cloudAmount',cloudAmount) write(*,*) ' cloudAmount (low and middle):',cloudAmount ! Height of cloud base call codes_get(ibufr,'#1#heightOfBaseOfCloud',cloudBaseHeight) write(*,*) ' heightOfBaseOfCloud:',cloudBaseHeight ! Cloud type (low clouds) call codes_get(ibufr,'#1#cloudType',lowCloud) write(*,*) ' cloudType (low):',lowCloud ! Cloud type (middle clouds) call codes_get(ibufr,'#2#cloudType',midCloud) write(*,*) ' cloudType (middle):',midCloud ! Cloud type (high clouds) call codes_get(ibufr,'#3#cloudType',highCloud) write(*,*) ' cloudType (high):',highCloud ! Release the bufr message call codes_release(ibufr) ! Load the next bufr message call codes_bufr_new_from_file(ifile,ibufr,iret) count=count+1 end do ! Close file call codes_close_file(ifile) end program bufr_read_synop
bufr_read_synop.py
# (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. # # Python implementation: bufr_read_synop # # Description: how to read data values from 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. import sys import traceback from eccodes import * INPUT = '../../data/bufr/syno_multi.bufr' VERBOSE = 1 # verbose error reporting def example(): # open bufr file f = open(INPUT, 'rb') # define the keys to be printed keys = [ 'blockNumber', 'stationNumber', 'latitude', 'longitude', 'airTemperatureAt2M', 'dewpointTemperatureAt2M', 'windSpeedAt10M', 'windDirectionAt10M', '#1#cloudAmount', # cloud amount (low and mid level) '#1#heightOfBaseOfCloud', '#1#cloudType', # cloud type (low clouds) '#2#cloudType', # cloud type (middle clouds) '#3#cloudType' # cloud type (highclouds) ] # 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 in the list above we used the # (occurrence) operator # accordingly. cnt = 0 # loop for the messages in the file while 1: # get handle for message bufr = codes_bufr_new_from_file(f) if bufr is None: break print("message: %s" % cnt) # we need to instruct ecCodes to expand all the descriptors # i.e. unpack the data values codes_set(bufr, 'unpack', 1) # print the values for the selected keys from the message for key in keys: try: print(' %s: %s' % (key, codes_get(bufr, key))) except CodesInternalError as err: print('Error with key="%s" : %s' % (key, err.msg)) cnt += 1 # delete handle codes_release(bufr) # close the file f.close() def main(): try: example() except CodesInternalError as err: if VERBOSE: traceback.print_exc(file=sys.stderr) else: sys.stderr.write(err.msg + '\n') return 1 if __name__ == "__main__": sys.exit(main())
bufr_read_synop.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) { printf("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) { printf("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; }