TOA Systems, Inc. (TOA) and Weather Decision Technologies, Inc (WDT) have partnered to bring the latest in state-of-the-science lightning detection technology to the United States by building and installing the United State Precision Lightning Network (USPLN). USPLN includes 87 Precision Lightning Sensors (PLS) over the mainland US and 6 PLS in the Caribbean to provide lightning detection over that region. The sensor coverage provides a detection efficiency of over 95% with accuracy better than 250m. The USPLN system uses a Time Difference of Arrival (TDOA) technique applied to the transmission from a lightning generated radio signal source. This TDOA technique is based on the time differences between the receptions of a radio signal at three remote receivers at known points from a single source at an unknown point. It is a highly accurate method of resolving lightning locations and determining whether the lightning is in-cloud or cloud-to-ground. Information from each sensor is sent to TOA and WDT redundant data collection sites where the data are used to determine strike locations. Lightning strike data and WDT value added products are disseminated to clients over the internet and/or through satellite delivery.

This paper will discuss the USPLN including detection instrumentation and methods, data collection and dissemination techniques, and accuracy results.