A Test of a Loran-C Multi-chain Positioning Method Using ASF Estimates

In this paper, we described a multi-chain ToA positioning method to estimate positions using all received Loran-C signals from multiple chains without constraining to a single chain and an ASF estimation method based on a receiver clock offset estimation. To validate these methods, we carried out a test. We firstly installed one receiver at fixed location in land and two receivers on the vessel. And we collected raw ToA measurements data from three receivers while the vessel moved along the path. Next, we estimated the ASF with the data provided by the land fixed receiver and measured the temporal change of ASF to generate the differential correction. The data provided by one of the receivers installed on the vessel was used to generate the ASF map. Loran-C multi-chain positioning was performed using the remaining receiver data. In this process, we mitigated the error by ASF using differential correction and ASF map. As a result, the horizontal positioning error was 2. 12m and 2DRMS was 24. 12m.