Loran-C Signal Stability Study: St. Lawrence Seaway

Since 1977, the U.S. Coast Guard has been conducting studies on the suitability of Loran-C as a precision aid to navigation in the harbor-harbor entrance (HHE) areas of the continental U.S. The final phase of this effort involves an assessment of the stability of the signals of the existing Loran-C system along with an examination of stability improvement methods. These efforts were extended to the St. Lawrence Seaway area in late 1981. Resulting data is analyzed in the report and indicates that the performance of the existing Loran-C system is inadequate to support precision applications in the St. Lawrence. The performance of Differential Loran-C is hypothesized and found to be, at best, marginal due to suboptimal system geometry.