geojson文件示例，

{"type": "FeatureCollection","features": [{"type": "Feature","geometry": {"type": "Point","coordinates": [102.0, 0.5]},"properties": {"name": "Example Point"}},{"type": "Feature","geometry": {"type": "LineString","coordinates": [[102.0, 0.0],[103.0, 1.0],[104.0, 0.0],[105.0, 1.0]]},"properties": {"name": "Example Line"}},{"type": "Feature","geometry": {"type": "Polygon","coordinates": [[[100.0, 0.0],[101.0, 0.0],[101.0, 1.0],[100.0, 1.0],[100.0, 0.0]]]},"properties": {"name": "Example Polygon"}}]
}

生成geojson文件的C++代码示例，

void GlobalMappingImpl::generate_geojson_gnss() const {Json::Value root;root.clear();root["type"] = "FeatureCollection";root["name"] = "SingleTrajectoryGlobalRes";auto& root_features = root["features"];auto _it_meas = _map_gnss._meas_map.begin();while (_map_gnss._meas_map.size() >= 1 && _it_meas != _map_gnss._meas_map.end()) {Json::Value json;json["type"] = "Feature";auto& json_properties = json["properties"];json_properties["name"] = "GNSS";json_properties["head_veh"].append(_it_meas->second->head_veh());json_properties["fix_type"].append(_it_meas->second->fix_type());auto& json_geometry = json["geometry"];json_geometry["type"] = "Point";json_geometry["coordinates"].append(_it_meas->second->lon());json_geometry["coordinates"].append(_it_meas->second->lat());root_features.append(json);_it_meas++;}static Json::FastWriter fast_write;auto* file = new std::ofstream("./debug_optimized_gnss.geojson", std::ios::trunc);if (file->is_open()) {*file << fast_write.write(root);file->flush();file->close();}delete file;
}