CPC G01S 5/26 (2013.01) | 4 Claims |
1. A method for positioning an underwater glider based on a virtual time difference of arrival (TDOA) of a single beacon, wherein the method comprises:
periodically sending, by a positioning beacon, a positioning message at a fixed time interval T, wherein the positioning message comprises longitude, latitude and depth information of the positioning beacon;
receiving, by the underwater glider, the positioning messages, and recording time of arrivals (TOAs) at which the positioning messages arrive at an acoustic positioning signal receiving module;
parsing, by the underwater glider, the positioning messages and storing positioning message data; and
calculating a position of the underwater glider, which comprises:
extracting, from the positioning message data, the TOAs tn−1, tn, and tn+1 of (n−1)-th, n-th, and (n+1)-th positioning messages, pitch angles θn−1, θn, and θn+1, heading angles ϕn−1, ϕn, and ϕn+1, and depths zn−1, zn, and zn+1 of the underwater glider at corresponding times;
creating virtual beacons VBn−1 and VBn+1 wherein plane coordinates of the VBn−1 are (XVB,n−1,YVB,n−1), a depth of the VBn−1 is ZVB,n−1, and latitude and longitude coordinates of the VBn−1 are (LVB,n−1,BVB,n−1); and plane coordinates of the VBn+1 are (XVB,n+1,YVB,n+1), a depth of the VBn+1 is ZVB,n+1, and latitude and longitude coordinates of the VBn+1 are (LVB,n+1,BVB,n+1);
calculating the position of the underwater glider based on the TDOA:
correcting TOAs of the virtual beacons VBn−1 and VBn+1 to obtain corrected TOAs tVB,n−1 and tVB,n+1;
wherein ri is a rounding function; and
calculating latitude and longitude coordinates (Ln,Bn) of the underwater glider at the time tn to complete the positioning of the underwater glider.
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