Experimentally determined accuracy and stability of Loran C signals for land vehicle location

Measurements of the stability of loran C signals in a nonurban area were carried out to determine the suitability of these signals for land vehicle location. Measurements were made at a 25- point grid within a 400 square mile area in central Indiana and extended over a ten month period. It was found that root mean square (rms) time difference prediction errors were on the order of 200 ns or less and the rms position errors computed from three time-difference measurements were on the order of 45 m over the ten month test period. Methods of improving position estimates using least-squares and maximum likelihood procedures are discussed.