RANDOM ERROR IN ESTIMATING SUBMARINE POSITION BY USING ONLY SOUNDINGS FROM THREE FIXED HYDROPHONES,
Abstract
Three hydrophones are assumed to be located exactly at the corners of a known equilateral triangle on a level ocean floor. The three sonically measured distances from a submarine to these hydrophone stations are used to compute the position of the submarine. Each of these three measurements is subject to a random error, which, in consequence, causes an error in the computed location of the submarine. This report derives methods for computing the amount of im precision in the resulting estimate of the sub marine's position. These methods were programmed for machine computation, and somof the results of the computations are shown in tables and contour maps. It is noted that, throughout large regions, precision improves considerably as the submarine moves from a height of 1/20 of the baseline length to a height of 1/5 this length. Finally, tables (from an earlier report) for a similar system, which uses an accurate depth (pressure) sensor in the submarine, are included for the reader's comparison. The addi tion of the depth sensor improves precision con siderably. The substitution of the depth sensor for one hydrophone either decreases or increases precision, depending upon the location of the submarine relative to the two remaining hydrophones. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 25, 1963
- Accession Number
- AD0419591
Entities
People
- K.p. Weller
- M.l. Eaton