"EQZ was Incorporated in 2013 and comprised of seasoned professionals with extensive experience in sensoring technology and operational security, systems engineering, product management, project management and customer service, currently 12 employees.
Following a strong demand for a new type of cost-effective and commercially feasible monitoring solutions for extended objects providing a holistic approach to the perimeter security. EQZ developed RELSEN product based on a distributed audio-seismic sensoring (DAS) approach.
Our products and services provides solutions for gas and oil industries, border security, critical infrastructure security, transportation.
EQZ is committed to maintaining its technology leadership position in the industry. This is achieved by substantial investment in Research and Development activities which enable solutions’ adaptation to new communication technologies, applications, standards and regulations"
This optical fiber will be called a fiber optic sensor (FOS). Typically FOS length is 40-50 km. In the systems of this class, all relevant information is transferred to Processing Center (PC) by the optical fiber, which is not only a sensor (FOS) but at the same time an effective and reliable channel for ordinary data transmission.
So, the vibrosensitive infrared stream injects into a FOS by means of a coherent semiconductor laser at the wavelength of 1550 nm. The simplified scheme of RELSEN represented on Fig. 1. Thus, the laser probes the FOS with usage of infrared stream. This probing is carried out in the pulsed mode. Pulses have a length of ~ 20-200 ns, with an interval of ~ 50-300 μs. The optical fiber is put into the ground, at the depth of 30-50 cm, at the distance of 5-10 m from the monitoring object and, as a matter of fact, it is an optical fiber sensor.
A sequence of speckles is received in the point of emanation using an ordinary welded coupler or a circulator. The central moment of the concept is the phenomenon that any seismic vibration arising on the surface of the optical fiber due to propagation of seismoacoustic waves from the sources of elastic oscillations, changes its local refractive index. Changes of the local refractive index are reflected in the time-and-frequency structure (TFS) of the respective speckle.
Analysis of the sequence of speckle structures using wavelet conversion apparatuses (the phase of singling out of primary signs of target signals) and Lipschitz classifiers (the phase of classification of target signals) makes it possible not only to reliably detect the target source of seismoacoustic radiation, but also to determine its type and area of occurrence.
