The OLMS is a system designed to monitor the effects of electromagnetic transients on ground and space systems.

The potential damage of sensitive electronic systems by lightning-induced electromagnetic transients is of concern to system designers, operators, and maintainers. The OLMS uses broadband sensors to measure radiation (electric and magnetic fields), as well as energy coupled to conductors (current and voltage). Processing of the signals is performed by two subsystems, in parallel: a transient processor (TPM) and conventional state-of-the-art digitizers. The digitizers are able to provide the waveforms desired by many users, but have inherent limitations in duty cycle and have large data storage requirements. The companion TPM electronics use SRI International-patented technologies to process the full-bandwidth signal in real time to extract parameters of interest, such as peak amplitudes and energy. Unlike digitizer based systems, the TPM is guaranteed never to miss a transient event and produces a very compact result data stream.

OLMS allows users to accurately monitor the electromagnetic threat to their sensitive electronic systems, and retest systems only if necessary. This is of value since over-testing leads to very expensive delays and schedule impacts, while under-testing may result in the deployment of a damaged system where repair may not be possible. The data from OLMS is available in real-time and is accessed by users via the Internet using a standard web browser interface.

OLMS was developed to support spacecraft launches at a number of launch sites in the United States, and has been operational since November 1999. The OLMS is currently installed at the following launch sites: SLC-37B [Delta IV] and SLC-41 [Atlas V] at Cape Canaveral, and SLC-3E [Atlas V] and SLC-6 [Delta IV] at Vandenberg Air Force Base. In addition, an OLMS is installed at the Integrated Processing Facility (IPF) near SLC-6 to monitor spacecraft during processing operations.