conver_bag_to_gpx.py

from pathlib import Path
import gpxpy
import gpxpy.gpx

from rosbags.highlevel import AnyReader
import sys

bag = sys.argv[1]
gpx = sys.argv[2]

def create_gpx_from_datapoints(datapoints, output_file='output.gpx'):
    gpx = gpxpy.gpx.GPX()

    for data in datapoints:
        lat, lon, ele = data
        gpx_track = gpxpy.gpx.GPXTrack()
        gpx_segment = gpxpy.gpx.GPXTrackSegment()
        gpx_point = gpxpy.gpx.GPXTrackPoint(latitude=lat, longitude=lon, elevation=ele)
        gpx_segment.points.append(gpx_point)
        gpx_track.segments.append(gpx_segment)
        gpx.tracks.append(gpx_track)

    with open(output_file, 'w') as f:
        f.write(gpx.to_xml())

# create reader instance and open for reading
with AnyReader([Path('/home/michal/wawa/1/rosbag2_2024_02_22-10_36_29')]) as reader:
    connections = [x for x in reader.connections if x.topic == '/fix']
    coordinates = []
    for connection, timestamp, rawdata in reader.messages(connections=connections):
         msg = reader.deserialize(rawdata, connection.msgtype)
         coordinates.append([msg.latitude , msg.longitude, msg.altitude])

    create_gpx_from_datapoints(coordinates, gpx)
    print ("done")