公开(公告)号：EP0752112A4

公开(公告)日：1999-10-27

申请号：EP96906173

申请日：1996-01-19

申请人： ASCEND CORP

发明人： PRICHARD D WAYNE ,  GUTHRIE JOE C

IPC分类号： G01S3/803 ,  G01S15/10 ,  G01S15/74 ,  G01S3/80

CPC分类号： G01S15/74 ,  G01S3/803 ,  G01S15/10 ,  Y10S367/91

摘要： A navigational device (10) for assisting a scuba diver in determining a direction toward and a distance from a dive boat (12) or to a buoy near the shore at which point the dive originated. The navigational device (10) includes a transponder unit (16) carried by a boat (12) and an interrogator unit (34) carried by a diver. The transponder unit (16) repeatedly pulses an identification signal to be received by the interrogator unit (34). The direction from which the signal is received is determined and displayed. When the distance to the boat (12) is required, a distance request signal is emitted from the interrogator unit (34) and a responding signal is emitted by the transponder unit (16). The distance between the diver and the boat is then determined by the interrogator unit as a function of the time elapsed between the emission of the distance request signal and receipt of the responding signal.