What does the survey brigade do?

Because it should be a surveying and mapping brigade, both the State Bureau of Surveying and Mapping and the General Staff Bureau of Surveying and Mapping of the People's Liberation Army have surveying and mapping brigades, which are engaged in geodesic ranging, marine survey, remote sensing photogrammetry and so on. At present, military maps are completed by surveying and mapping brigades in various military regions. Each military region has a surveying and mapping brigade, which not only completes the surveying and mapping tasks of the General Staff, but also undertakes the engineering survey tasks in some places! The army's surveying and mapping brigades are all active troops and regimental units!