Dedicated timing reference distribution system for high accuracy synchronisation of networked RFeyes

The RFeye SyncLinc system allows multiple RFeye nodes to be phase locked together to allow each receiver to capture data within one sampling clock cycle of another by distributing an accurate timing reference from a master node to a group of slave nodes. This system operates via dedicated hardware over standard CAT5 cable network that is independent of the data transfer network, and therefore is not vulnerable to the buffering delay and associated degradation in performance which can occur over busy shared network hardware.

The use of RFeye SyncLinc wired networks allows more accurate timing control for the RFeye nodes over and above that of GPS timing synchronisation (GPS synchronisation on the RFeye node is also available). There are also situations where GPS synchronisation is not possible, practical or desirable, for example with indoor in-place monitoring systems (IPMS) and systems requiring invulnerability to GPS jamming or failure.

Existing wired network synchronisation technologies can synchronise devices to within the sub-microsecond range, however the RFeye can sample at a maximum rate of 40Msamples/s, therefore to take full advantage of this performance and synchronise networked RFeye Nodes down to the level of individual samples, a timing reference accuracy of better than 25 nanoseconds RMS is required. The GPS timing synchronisation option can achieve around 35 nanoseconds RMS between RFeye nodes, and the RFeye SyncLinc system can typically achieve less than 10 nanoseconds RMS between RFeye nodes. The SyncLinc system is also significantly more cost effective for typical network deployments, when compared with the expensive supporting hardware associated with alternative synchronisation technologies.

RFeye SyncLinc therefore allows comparison and correlation of data between individual nodes in a network to within a few nanoseconds, which in turn allows advanced correlative operations including high accuracy power on arrival (POE) geolocation for IMPS and wide-area time difference of arrival (TDOA) geolocation even for transient and low power signals, while retaining the full performance of the RFeye.