Underground Activity Detection System

Problem identification

Shallow tunnels present both military and homeland security threats. Smugglers with intentions of avoiding border security have turned tunnels into transit routes for trafficking weapons, people, drugs and other illegal materials. Shallow tunnels are also used by prisoners to escape prisons. While drug and human trafficking have long been border concerns, the threat of international terrorism has transformed the effort to detect tunnels into a national security priority.

Imminent threats include assailants entering military fortifications by burrowing under buildings, detonation of high grade explosives from foundations of high security facilities, and high level prisoners escaping detention centers through tunnels.

Real-time monitoring of the ground surrounding security installations, oil and gas rigs installations, banks and prisons across the country is an effective solution to this problem.


Develop and verify an innovative, efficient, practical, reliable and easily deployable technique for real time monitoring of soil structure integrity, and localized detection of shallow tunnels and perimeter and border protection.


This solution was designed for detecting any tunneling and digging activity nearby any infrastructure. It is typically used to protect security installations, any government facility, border crossings, airports, banks, sea ports, prisons, pipelines and oil and gas rigs infrastructures.

Solution’s scope

It can fit into any perimeter intrusion detection solution such as Smart Fence or underground intrusion, including a variety of vertical markets and facilities for multiple applications like military installation, critical infrastructure sites, and so on.

Elpam’s comprehensive on-site turnkey solution includes the following phases:

  • Analyzing
  • Initial design
  • Implementation
  • Commissioning


Detection Method – How it works?

ELPAM’s system uses ground based Geophones (Seismic Sensors), buried near the walls or foundations of a structure, to detect tunneling attempts and other  suspicious activities nearby protected assets.

The system can recognize the seismic footprint of a variety of activities like digging, drilling, hammering, etc. and can measure their intensity and duration.

These Geophones measure energy waves in the earth. When an activity is registered in the protected area, the seismic sensors (Geophones) produce a signal which is processed in real time through an advanced algorithm, identifying which type of activity has been registered (digging, drilling, hammering, walking, vehicle, and so on).

The Seismic Sensors combine Geophones with advanced intrusion recognition algorithms that analyze the seismic signals to effectively filter out false alarms. This intelligent signal processing technology provides a high probability of detection and an extremely low false and nuisance alarm rate (reduces unwanted background noise while increases the sound of terrorist and criminal activity).

The underground sensors can be installed at varying depths and distances from each other. Each sensor has an adjustable detection range that is usually overlapped by several units for increased reliability.

By design, the installation of the sensors can be divided into the areas (zones) of disclosure. This method can pinpoint the excavation tracks.

The computerized system processes the signals picked from the seismic sensors (Geophones), processes them, and by smart algorithms developed especially by ELPAM, displays the results over the monitors (including cellular phones).

System layout

A – Seismic Sensor unit

  • The sensors are installed approximately 150 meters  apart from each other.
  • The Seismic Sensor unit is buried near the walls of the building
  • Each unit is an autonomous entity with a distinct ID.
  • The Seismic Sensor unit is software-based (can be updated).
  • The Seismic Sensor can transfer the alarm message to the operator through wireless RF or wired.
  • The Seismic Sensor is powered by a lithium battery pack or through a wire from the central power source.

B- Seismic Sensors Interface Unit (Gateway)

  • Connects a group of 2 to 8 Seismic Sensors
  • Connection can be wired or wireless
  • Can be attached to the power hub
  • The data from the unit can be connected to the Communication and Power Unit (see “C” below).

C- Communication and Power Unit

  • Connected to Seismic Sensors Interface Units
  • Power and Communication Hub
  • Can be attached to the power hub.
  • The data from the unit can be connected to a management computer through RS485 or TCP/IP

D – Local Management Computer

  • Can collect all the DATA received from the Seismic Sensors Gateway.
  • Gives the possibility of a local alarm or alarm transmission to a remote control system

E – Wireless (RF) Seismic Sensors – option

Features & Benefits:

  • Robust and innovative technology
  • Weather proof – Sensors are resistant to temperature changes, humidity, rain, snow and wind
  • Adaptable to various types of terrain e.g. sand, clay, soil, etc
  • Sophisticated signal processing
  • Detection resolution ±10 meters
  • Easily integrates with other smart sensors to provide multi-layered protection and deliver data fusion for greater accuracy such as surveillance or back-up systems
  • Full control of system features from remote center
  • Extremely difficult to locate and disconnect
  • Multiple applications including borders, nuclear plants, oil pipes, chemical plants, military installations and critical infrastructure sites
  • Very low infrastructure expenses
  • Low system power – use inexpensive cabling solutions
  • Does not interfere with site aesthetics
  • Easily integrated into a full turnkey solution – including detection systems, perimeter protection and security management system

System’s specifications

  • Operating temperature -30°c to +60°c
  • Relative humidity 100%
  • Operating voltage 30-40 V D .C.
  • Power requirements 10mw /sensor
  • Enclosure sealed to IP67, UV protected
  • Detection range adjustable

GEOPHONE – Technical Specifications

  • Resonance Frequency: 14Hz ± 2%
  • Resistance: 395Ω ± 2%
  • Sensitivity:0/275v/Cm/Sec
  • Working temperature: -30 °C ÷   +60°C
  • Weight:6Kg
  • Diameter:60mm
  • Height:88mm
  • Material: Aluminum60-61T6
  • Coating:anodizednatural


Read more about:

Tunnel detection

Human activity detection in exposed tunnels

Aviv Moshe st 8 Or Yehuda, 6037130 Israel
Tel: +972.353.370.19
Fax: +972.353.370.63
Email: office@elpam.com
Website: www.elpam.com