Questionnaires can be divided into job-oriented and personnel-oriented. Job-oriented questionnaires place more emphasis on the conditions and results of the job itself, while personnel-oriented questionnaires focus on understanding the work behavior of staff. Questionnaire method can be all-encompassing, to collect as much information as possible about the work, can collect accurate, standardized, clear meaning of the work of the information can be arranged at any time to investigate. However, the questionnaire questions have been set in advance, the survey is difficult to deepen, the collection of work information is affected by the level of questionnaire design, and the level of knowledge of the incumbent staff requires a high level. To carry out the work survey, generally the questionnaire method is the main method, supplemented by the interview method and observation method. The sonobuoys are "directional", belonging to the close-range precision monitoring and alarm system, which can help the precision strike. "Non-directional", belonging to the medium and long range early warning system, to provide anti-submarine early warning report.