COMMON-VIEW LORAN-C AS A BACKUP TO GPS FOR PRECISE TIME RECOVERY

摘要

The LORAN-C network is being recapitalized to serve as a backup to GPS for navigationrnand timing. LORAN-C is being investigated as a precision (sub 100 ns) time recovery systemrnfor use in the continental United States. Traditionally, LORAN-C time recovery has beenrnlimited by propagation effects (both spatial and temporal) to provide time recovery in thernmicrosecond range. By employing common-view techniques long used in GPS, the potentialrnexists to enhance time recovery performance by over an order of magnitude using LORAN-C.rnThe LORAN-C Accuracy Panel (run by the US Coast Guard) has sponsored a research projectrnto collect data and determine the performance level for time recovery using common-viewrnLORAN-C. This paper presents the results of that work.rnThis paper begins with a short overview of the LORAN-C recapitalization project, with anrnemphasis on timing enhancements at the transmitting stations. A description of the commonviewrnLORAN-C test network follows. Data collected in Boulder will be corrected via commonviewrnusing a near field station and a far field station. Results will be analyzed to determine therndependence of time recovery precision on distance.